PROJECT FAO/ETH/82/O08
DEVELOPMENT OF IRRIGATED AGRICULTURE, PHASE II
A cooperative project of the
Government of Ethiopia,
Food and Agriculture Organization of the United Nations and United Nations Development Programme
BUTAJIRA PROJECT AREA
SOILS AND LAND SUITABIl ITY FOR IRRIGATED AGRICULTURE
M. YASIN JAVED MIRZA FAO Soil Survey Consultant
WATER RESOURCES DEVELOPMENT AUTHORITY
ADDIS AEA0A
1986table oe contents
SUMMARY..
INTRODUCTION.............................................................
P a £ e ..iv
................ 10
I. j j ■>
1.3 THE
2. 1
2.2
General............................ .. ..............• ' ’’
project rationale and terms ol
»■ reference...
.... 3
Acknowledgements...................................................
... 4
2.3          Geomorphology and physiography................................................................
Location and extent.................................................................................... V / 1 1 ill < i I t • • • • •
.... 4
...............b 
............ /
r?
2.4
2.5
Hydrology...................................................
Present land use and natural vegetation....
2.6          Population ami socio economic conditions...
2.7 Marketing and communication.............................................................
...............8 
.... 9
............10
.................................. 11
3 . SOILS
3.1           General nature
3.2           Main soil types
3.3            Mapping units................................................................................................................... J
LAND
4. 1
SUITABILITY FOR IRRIGATED AGRICULTURE
General land characterlstics/qua1ities.............................................................................. 4.1.1              Climate, growl ng periods and
adapted crops
4.1.2              Irrigation water quality and
availability.................................................................................................. 4.1.3              Topography
4.1.4              Soil depth and rootability
4.1.5              Available water capacity of soils 4.1.6              Soil permeability and water intake
2 9
2 9
2 9
3 1
3 I
3 1
3 1
rates............................................................................................................ 3 J 4.1.7              Drainage and flooding32
4.1.8              Soil fertility and pH33
4.1.9              Lime content
4.1.10            Salinity and sodicity or acidity34
4.1.11            Soil workability34
4.1.12            Soil erosion................................................................................................ 3 4
4.2
I . 3
4.4
4.5
4.6
4.7
4 . b 4.9
The classification system Class-determining 
Crops
and 
input
levels              <?
onside
35
factors’3^ red33 
Crop requirements............................................................................................................ ^9
Assumptions made
Land suitability classification 
Land suitability mapping units
Specific management requirements****'
5.
CONCLUSIONS AND RECOMMEND AT I ON b
5.1           Main conclusions
5.2           Specific recoiuueixlat ions ......... .............................................-1 i-
Page
LITERATURE CONSULTED55 APPENDICES
1 . METHODOLOGY57
II.         WATER INFILTRATION AND HYDRAULIC CONDUCTIVITY
STUDIES60
Ila. Water infiltration studies^0
lib. Hydraulic conductivity studies62
III.        SOIL GENESIS69
IV.       LAND SUITABILITY ASSESSMENT ACCORDING TO SOIL
TYPES (Table 12)73
V.         DESCRIPTION OF TYPICAL SOIL PROFILES AND SOIL
ANALYTICAL
DATA77
Va.
Profile
descriptions77
Vb. Analytical data95
MAPS
Map 1: Location of the project area3/4
Map 2:              Soils (and land units), scale 1:25,000. . ..20/2 1
Map 3a:             Land suitability for irrigated agriculture
under medium level of inputs, scale
1 : 25,00045/46 
Map 3b:             Land suitability for irrigated agriculture
under high level of inputs, scale
1:25,00045/46
Map 4:               Soil observation and infiltration test sites
59/60
TABLES
Table 1:                  Agroclimatic data for Ogelcho5
Table 2:                  General cropping pattern and yield levels
among        smal        1-ho        1        ders        of        mid-Meki        aread 
Table 3:                  Characteristics of main soil types16
Table 4:                  Description of soil mapping units21
Table 5:                  Climatically adapted irrigated crops30
Table 6:                  Grading and definition of class determining 
Table 7: Classification of land units with respect to
factors37 
different factors
grades
of
class-determining 
Table 8:                  Crop requirements in terms of factor
grades........................................................................................................ 49
Table 9:                  Land suitability classification for different
crops       at       medium       and       high       levels       of       input...42 Table 10:                Land suitability mapping units, their extent
and component land units45-i i l-
Pagr
Table 11:                 Crop-wise assessment of land suitability
. .46
Table 12:                  Land suitability assessment according to
. . 73
Table 13:                  Analytical data of soil types Al, A2,
R1 B2 il3 and C
.....................................................
. . 96
Table 14:                  Available water capacity of soil types Al,
B2 and B 3........................................................................................................
. . 9K
F 1 CURES
Fig. 1 :                           Schematic profiles                             of different soil types
showing important                                horizons and textural
changes upto 150 cm depth
15
Fig. 2(a,b) to 6(a,b>:                                         Water intake curves and
wetting profiles of different soil
types...................................................................................................  64 to 6Hi v
S___ U__ M M _A ft Y
The Butajira land with 
we a th ere d thick, very
structured content t here
1 i g h t almost
project very deep 
ignimbrite,
dark greyish topsoil which has about
area          represents          an          almost
flat
t    rac1    o    f
overlying 15 40cm
c r uuib matt er sol Is, thick thick,
so i Is
All brown
formed in volcanic ash soils invariably have a
to bl ack, granu1 ar Io 2 to 4 percent organi<
p e r m e a b L e The rain 
and
and exists,
grey dense
act as
is very fert ile. However, in most of t lie immediately below the topsoil, a 10-20cm
silty layer abruptly underlain by a 15- 35c id clayey layer, both of which are slowly 
weak barriers for plant roots and water,
water,
therefore, stagnates fsortagnates for significantly long 
pcriods l he occ u r layers
t j e 1 o w
the topsoil above these layers
which would affect
growth of most crops.
l Dimed i atrly 
ploughings water
dej> I h 
must to
be
after a broken 
improve
t he
Similar situation may be expected to 
medium or heavy irrigation. These
by subsol1lng/chise11ing or deep 
subsoil conditions for rooting and 
penetration.
may even then be
A
t hese
covered bet ter
sol Is.
A     considerable
shallow drainage system at about required to get high crop yields part of the project area
by soils
drained.
ploughings),
a g r i c u 1 t u r a 1 management
nor
which have no slowly permeable layers and are These soils need neither subsoiling (or deep any shallow drainage system to get
product ion; for that purpose,
but they do requie careful
The eastern and southwestern
of the
tii an 4 moderately precision c over
project
percent
area have gentle slopes of 1 to 3 percent
along the river) and the soils have slight
severe risk of sheet erosion. levelling, or contour ploughing and good
during rainy season, will be required to protect
Terracing
60c  m from
i s    also
high water parts (more
t o and
v e g e t a t 1 v e the soils
medium
and 
high 
levels
of
inputs.
against that risk.
Since           the           proposed           land           use           types           under           irrigation 
were not defined  in  the terms of reference, the project land  was
evaluated  for all important crops adapted  to  the climate at
2130         ha         was
ha        (about        74 
An 
area
of
surveyed 
for
the
project.
Out
of
this
area,
1572 
percent
of
the
total)
are
moderately 
to 
highly 
suitable
for
growing 
of
most
irrigated 
crops
adapted 
to 
the
climate,
at
both 
levels           of
inputs.
In           general,           the           land           is           specially           suitable
for growing  of foodgrain  crops and  commercial production  of vegetables and  pulses. Orchards of citrus, grapes, olive and pomegranate can also be successfully grown.Out of the*  total suitable land, only  143  ha which  lie below the contour line of 1812  m are counudiidab  le by  gravity channels from the proposed  dam, while other part of the land will require pumping  of water for irrigation  to  about 12  m height. The land  coimnnndab1e by  gravity  channels has, however, relatively  good  drainage conditions with  seldom occurrence of the above described  slowly  permeable layers in  subsoils. But it has slop«*s of 1  to  3  percent and  has a minor limitation  of sheet erosion  by  rain  water which  would  require special techniques for soi 1 management .1.            1 NTRODUCTION 1 . 1 Gene r.a I
The t rac t s
Project           Area           represents           one           of           the
various
I hrough perennial Developmen t possibi lities River near
i rrigation
H uI aj i ra
of land
considered            for            extension            of
irrigation 
< ons t ruc t st reams
of
of K o s h e engineers
ion of under
irrigated construct ing
medium        aand   nJ smalslmall        scale        dams        on        some
an
FAO assisted project ’ETH/82/008 Agriculture’ in Ethiopia.
an irrigation dam over the Woja
The
village have already been in cooperation with
explored by a I earn of cooperation with the Water Resources
D e v e 1 o p hi c n t  Aut hori t y
Ethiopia. A report on 
of Ethiopia. A report on land resources
and however, report is land use
irrigated
potential of required
the
before
i   n   tended planning,
to especially
for irrigated agriculturearea for irrigated agriculture was, project could be exectut heepr d. oject could be executed. This
serve the purpose as well as to help in with respect to the choice ol
c r o p s
and their management requirements,
In add it ion 
to
alternatives,
i rr igut ion 
irrigation
in
g u i d i n g
assessment of
i n 
it
needs
designing of the dam, select ion of
me t hods
wou 1 d and
and
t he
the
choice of most promising land use
infrastructure requirements for proper of inputs and credits etc.
provide a sound basis for estimating the
water distribution and, to some extent,
water control and supply
The        report        may        be        regarded        as        consisting        of        3        major
parts. Tile first part (Chapter 2) gives a general information 
on 
the
ecology 
and 
socio-econ
omic
enviro
nments
of
the
project
area.
The
second 
part
(Chapter
3)
deals
with 
the
soil
resources
of
the
area,
indicating 
the
distribut
ion 
and 
extent
of
various
soil types on  a map  of 1:25,000  scale. The third  part 'Chapter
4) presents an  assessment of land  suitability  for irrigated 
agricultural
use,            with            specific            reference
to            crops            and            the
envisaged  levels of inputs and  management; the areas having  the
same potential for the selected  crops are delineated  on  two  land 
suitability             maps             of
1:25,000             scale
representing             suitability             al
two  different input levels. Main  conclusions derived  from tin 
study  and  specific recommendations on  land  use and  soil
management are included  in  a separate chapter following  the land 
suitability             classification 
for             guidance             of
the             government,
the
project executing  agency  and  the land  user. The appendices
include details about the methodology  adopted  for the study, the
water-
infiltration            and            hydraulic            conductivity            studies            made,
soil
genesis,           land           suitability           assessment           according           to           soil           types           and 
profile           description           of           important           soil           types
identified 
in 
th« 
area,          along          with          the          analytical          data          of          soil          samples          collected from the profiles.
The terminology used to describe soils and land suitability assessment is explained in the USDA’s Soil Surve} Manual (Soil Survey Staff, 1951), Guidelines for Soil Pi< file Drsiription (FAO, 1977), FAO UNESCO’s Legend for Soil Map of I he-3-
sites,
to           be           followed           by           excavation           of           the
Elstun- profiles with 
distribution of water after infiltration.
respect to 
lateral
sites         to study and          vert i ca I
Finally,
the
results
of
soil
survey 
were
to 
he
compiled          in 
the
form
of
maps
and 
report
includin
g 
suitabi
lity 
assessment
for
various
irrigated 
drops
rele
vant
to 
the
proj
ect
area         and 
giving 
specific
recom
mendations
for
follow
up 
action 
by 
the FAO/Government of Ethiopia.
1.3             Acknow 1edgmen t s
The         soil         survey         of         the         project         area         was         carried         out in   c   o   1   1   a   b   o   i'   a   t   i   on   with   Mr.   Steven   Paris,   1A0   Soil   Expci   I,   w   h   o   s   • whole-hearted           cooperation           in           field           work           and           useful           suggest           ions
during             writing             of
the
report
are             highly             appreciated.             The
technical assistance in  the field  work  rendered  by  Messrs. Arnaha
Getachew and  All Muhammed, Soil Technicians from Water Resources
Development              Authority,
is
thankfully 
acknowledged.              The
author
feels highly  obliged  Io  Mr. E. De Pauw, FAO Soil Scientist, for
providing  preliminary  information  about soils and  landforms of
the area gathered  by  him through  a rapid  reconnaissance soil
survey  before our departure for the field, and  for rendering 
technical guidance during  writing  of the report. Thanks are due
to  Ato  Tclahoun  Eshetu, the National Project Coordinator, for
providing  the necessary  facilities and  equipment for the field 
work  and  for the report writing. The collaboration  of the staff of Soils Laboratory  and  Cartographic Section  of WRDA, and  of the
National acknowledged.
Soils               Laboratory,               Addis               Ababa, Finally, the author owes thanks to Ms. Tegist
are
also 
duly 
Bekele,           the           Project           Secretary,           whose           efficient           typing           made possible to finalize this report in time.
it»-u-
2 . TEOT AREA
2 . 1 Location and extent
The
Butajira
project
area
comprises
a
nearly 
flat
tract         of
land 
covering 
2130 
hectares
near
Koshe
village
along 
Zwai-Butajira
road 
in 
Mareku 
Wereda
of
Shewa
Region 
in 
Ethiopia. It is mainly  located  along  the west bank  of the Woja River northeast of the Zwai -Butajira road, roughly  between 8° 01  ’ and  8°06’N latitudes and  38°30’ and  38°33  E longitudes. It is bounded  by  the Woja River in  the southeast, by  the Zwai-Butajira road  in  the southwest, by  a contour line of
1812       in       (200-500       m       across       the       river)       in       the       south       and       by       a straight        line        approximately        parallel        to        and        about        3        km        away        from the        river        in        the        northwest        which        is        cut        near        perpendicularly        at about        6        km        distance        from        the        road        by        another        straight        line        in the        northeast.        It        ranges        in        elevation        from        about        1808        m        near the        river        bridge        to        about        1823        m        on        its        northwestern        boundary. A        location        map        of        the        project        area        is        fixed        opposite        to        this page.
C1 i m a t c
There        are        no        climatic        data        for        the        project        area.        The nearest          meteorological          stations          for          which          the          data          are         available are        Zwai,        Meki        and        Butajira        which        are        located        at        distances        of about      20      to      40      km      from      the      project      area      and      occur      at      elevations of       1640,       1650       and       2100       iu         respectively.       As       the       project       area       lies at       elevations       ranging       from       1808       to       1823       m,       and       as       the       climate varies          significantly          with          the          elevation,          the          climatic          data          from any        of        these        stations        cannot        be        used.        An        interpolation        from        the isohytes        drawn        on        the        ’Annual        Rainfall’        map        by        Makin        et        al (      1975)      yields      a      figure      of      about      750      min      of      mean      annual      rainfall
for
the             project
area.             The
rainfall
distribution             patterns
studied  from the nearby  rain-recording  station  (Meki and  Zwai) indicate that the main  rainy  season  occurs during  June to September when  moist winds from the Indian  and  Atlantic Oceans converge over the highlands of Ethiopia. About 60  to  65  percent of the total annual precipitation  occurs during  this season. 1he period  from October to  December is almost dry  with  only about 5  percent of the annual precipitation, while the remaining 30  to  35  percent precipitation  occurs during  January  to  May  with an  erratic distribution. The rain  often  falls in  short heavy bursts accompanied  by  thunderstorms with  intensities of upto  100 
min          per          hour.          Hail          also          commonly          occurs          during          heavier I bunder s t onus .-5-
Table 1:        Agnx.1 biutic data for Ogelcho
(Alt: 1800m, bat: 8®04*,Long:                  39°02')
Jan.      Teh.    Mar.    Apr.    May     June     July   Aug.     Sep.     Oct.    Nov.     Dec.    Year
Precipitation
(rm)
12
47
44
85
41
72
132
118
89
32
11
6
689
Mean dally temp. (°C)
18.3
19.4
20.2
20.9
20.7
20.2
19.5
19.2
18.8
19.3
17.9
17.5
19.3
Mean daily nax.
temp. (°C)
26.2
26.6
27.4
28.5
2b.6
27.0
24.6
24.2
24.4
26.2
25.5
26.2
26.3
Mean daily min.
temp. (°C)
10.3
12.1
12.9
13.2
12.8
13.4
14.3
14.1
13.1
12.4
10.3
8.8
12.3
Mean day tenp.
(°C)
21.1
22.0
22.8
23.6
23.5
22.6
21.3
21.0
20.8
21.8
20.6
Mean night
20.6
21.8
temp. (°C)
15.5
16.9
17.6
18.2
17.9
17.7
17.5
Av. Vapour
17.2
16.6
16.6
15.0
14.1
16.7
Pressure
(m. bars)
10.9
10.8
11.8
12.4
12.9
Av. wind speed 
14.9
17.2
17.6
16.9
14.3
10.1
9.6
13.3
at 2m (m/s)
1.3
1.0
1.0
0.8
Sunshine durat
0.9
1.5
1.1
1.0
0.7
0.8
1.2
0.9
1.0
ion (%)
84
79
70
Solar radiation
63
61
61
41
47
44
71
80
78
64
(cal/cm day)
505
.524
Potential Evapo
520
501
484
474
403
433
422
504
501
472
478
transpiration
(mn)
112
107
127
123
125
118
101
103
96
111
108
100
1331
Source: FAO (1984)
The data show that the mean da i y temperatures vary little during the year, the maximum variation being 3.4°C. But the diurnal variations are high ranging from 10°C during the wettest period (August) to 17.4°C during the driest period (December). The mean day temperatures generally fluctuate around 22°C while the mean night temperatures vary between about 1U and 18°C. November, December and January are relatively cool months while April and May are relatively warm. No frost occurs during any part of the year. 
The rate of potential evapotranspiration varies from 3 to 4 mm per day.-6-
2.3 Geomorphology and physiography
The         project         area         forms         part         of         a         low         plateau         of ancient          basement          rocks          which          is          overlain          by          Pliocene          weathered 
ignimbrites            (consolidated            ash            flows)1'            and            is
further
covered 
by  a relatively  recent (probably  of middle to  late Pleistocene period) and  loose volcanic ash. The ash  was later compacted  to form an  almost uniform layer of 1  to  1.2  m thickness over the ignimbrites, thus the plateau  being  transformed  into  extensive
’old volcanic ash plains’
An
the
southern 
deep  I  h  r  o  u  gh sediments.
meandering            course. short periods of rainy season confined only to some low Consequently, the volcanic ash
old river stream, the Woja River, which runs along and eastern limits of the area had been cutting 
the ignimbrites with little deposition of its
It has by now been deeply incised and has adopted a The area which is flooded by the river for
material is found uncovered by
is extremely
limited and is
parts of its
s t eep margins .
alluvial
sediments            upto            the
considerable            part probably when the riverbed was
along            the
river bank, with  of course a river bank  having  been  eroded  away higher.
A         major         part         of         the         volcanic         ash         plains         in         the northwest        has        a        very        flat        topography        with        less        than        1        percent slope       while       its       southeastern       part       has       a       gentle       slope       of       1       to       2 
percent toward  the river, except for a narrow strip  along  the river which  is rather steep  and  dissected. A small part of the plains toward  the extreme southwest (across the river) has
exceptionally an undulating topography.
Ea
st
of
the
river
and 
almost
par
allel
to 
the
latter,
but
outside
the
proj
ect
area,
there
runs
a
hi
gh 
escarpment
of
Mareko 
Ridge
which 
slopes
steeply 
tow
ards
the
river.
The
volcanic
ash 
was
a
lso 
probably 
depo
sited 
over
these
slopes
but
much  of it has been  washed  down  by  rains to  the lower slopes where a narrow strip  of ’alluviated  ash  plains’ has been 
formed. The alluviated  ash  material is distinguishable from the old  ash  by  virtue of it being  relatively  less compacted  and having, in  contrast to  the old  volcanic ash, more variable thickness over the ignimbrites. These plains have gentle slopes of about 1  to  3  percent which  gradually  decrease towards the river.
If Mak
a I       (1975).-7-
1 s Hive r ln
2.4 Hydrology
The only source a tributary of the Meki
of surface water existing in the area Hiver, i.e. the Woja Hiver. The Woja
is the
.
along smal 1 northwest. incised Iherefore banks.
its course as well as with some contribution by another stream originating from the Gurage Mountains in the
The stream is quite narrow and becomes deeply when passing through the project area.
, ineffective to flood any part ol land beyond its
The stream flows with full discharge only during a short
a peperernni  ennialasl tsrteraemamwwiuuu    hich uor i  iginates from
southwest and has a substantial recharge from the swamps ----- ------  - -
-•—* ^he Lake lula
It is,
we t
are
season (July to September) while the dry season water flows extremely variable and generally very low. According to 
Makin        el lor        some years out Woja river,
al (1975), the Meki Hiver has a probability to dry up period during December to March for, on an average, 10 
of every 100 years period, which also applies to the
the latter
being a tributary of the Meki.
The         analyses         of         river         water         samples         from         the         inLd-Mcki valley        (probably        of        the        Woja        tributary        of        the        Meki)        taken        in January 1974 are given by Makin et al. (1975) as follows:
EC    at    25°C    :    .3    mmho.ciu-1 pH: 7.6
Cations (meq.1 1 ) :
Ca: 1.5
Mg: .95
Na: 1.40
K: .41
Anions (meq.1  ):
Cl: .08
SOn;    .30
C03     and   HCO3   :   3.00 SAW: 1.3
RSC:   .5 meq.1-1
1
The
EC and
Zwai-Butajira 1 be .28 mmho.cur Westcot ( 1985 ) purposes. The
nd ph of the Woja river water
road bridge during jnid-November 1986 in1 and 7.4 respectively. Accordin
during |
this water can be
water quality would 
periods of high river discharge
to dilution effect of rains.
measured near > were found to 
. According to Ayers and used safely for irrigation 
probably be much superior (i.e. the wet season) due
The domestic channel from the
river at present acts as the r
and 
livestock             consumption 
major source of water for
It
aicn             ~             1K/I
for        the        whole        project        area        ind        serv*s           as           a            drainage area during the wet season ^cumulates all runoff-8-
The
systernat ical1y existing in saline and analysis of groundwater part of the
groundwater investigated.
the area
occurs at
the water for irrigation 
project area.
resources have not so far been Observation of a few wells
___
reveals that the groundwater is slightly depths varying from 20 to 30 metres. h-
has, however, been made. The purposes was not in practice
No
use
of
in any
2.5 Present land use and natural vegetatj_un
At
present,
the
major
part
(over
75 
percent)
of
the
project
area
is
used 
for
rainfed 
farming 
of
mainly 
sorghum, farmers
red also 
pepper         and         tef         crops         at         subsistence         level,
maize, Some
in by very 
addit ion tenants
grow        peas,        haricot        beans,        wheat,        barley        and        lentil to        the        above        crops.        The        land        is        cultivated        mostly 
who  have extremely  meager capital resources and  hold 
smal1-sized
plots scattered at different places, all
const itut ing 
together        generally        not        more        than        2        ha        but        casually 
upto
the
5      or      6      ha      per      tenant.      The      level      of      farming      is      very      low      and only input made, else than their family labour, is the seed
which, though  of poor quality, is used  in  considerably  high amounts to  compensate for low rates of germination  and  losses due to picking up by the birds and soil fauna. For seeding
purposes, the land  surface is shallowly  scratched  by  means of an 
indiginous,            cattle-drawn,
local            country            plough.            The            seed            is
then  broadcast and, after another ploughing  (which  is avoided  by many  farmers), the land  is left to  nature for the crop  to  grow and  mature. No  fertilizers or pesticides are used; nor any  kind of interculture is practised  and  the fields remain  heavily infested  by  different kinds of weeds. The general level of crop yields as well as the quality of produce is very low.
A general cropping pattern and levels of yield in the area are given by Makin et al (1975) as in Table 2.
Table 2:                                   General cropping pattern and yield levels among smal1-ho 1ders of mid Meki area
% of farm                      Average yields
Crops
area grown
(q/ha)
Maize*                                            47
Peas and beans
7.2
22
Pepper
16
3.8 (dried)
Tef
2.8
6
0 thers
9
5.2
♦ Probably includes sorghum-9-
A          caretui          estimate          made          by          the          author          during          field work        from        the        standing        mature        crops        of        maize,        sorghum        and        t»*l. however,         gives         about         double         the         figures         of         average         yields         quoted in         Table         2.         This         may         probably         be         attributed         to         the         unusually favourable          rainy          season          during          this          year          or          an          unfavourable          one
during the year when Makin made his study.
The
red 
peppe
r
is
the
main 
cash 
crop 
of
farmers
while
a         small
proportio
n 
of
cash 
income
is
also 
contrib
uted 
by 
limited 
sale of other crops including peas, beans and lentil.
The
glasses which 
tall and short
to 80 percent. Myparrhenia, Aristida,
uncultivated part of the land grows natural are extensively grazed by cattle and goats. both 
grasses are found which have a ground cover of 60 The most common grasses belong probably to
Cenchrus and Cynodon species.
Mos t
natural
for the fuel
tree
species growing on grassland have been cleared oil and timber needs of the local inhabitants. The
species which  still persist even  on  cultivated  land  are mainly Ficus and  Acacia, with  a few others which  are relat ively unimportant. A moderately  thick  stand  of different species of trees, shrubs and  bushes is, however, found  in  relatively  moist areas along  the river bank. These provide some grazing  for the livestock  as well as serve as a source of fuel wood  and  sticks for building of farmers huts (tukul).
2.6 F op u I at i on_ and s o cj o - e cony mi c c o_n d i_tj on s
No          data          regarding          the          population          of          people          living          in the           area          are           available.          It          way,          however,          be          roughly          estimated that        there        are        presently        2        to        3        thousand        people        living        in        t        lie area.                 Most of them are farmers with medium to large sized
families while a few earn their living by working as labourers.
The common food grains are maize, sorghum and tef which are
usually consumed in combination with cooked pulses or meat.
Safe drinking  water is scarce. There are a few open  wells which supply  drinkable water but in  general most of the water needs for drinking  or other domestic purposes have to  be met by  the river. The level of integration  of the local peasants into  a cash economy appears low.-10-
2.7. Marke t i n g and communication
The          project          area          is          well          connected          with          the          nearby markets        of        Koshe,        Lnseno,        Butajira        and        Zwai,        as        well        as        to        the capital         town         of         Addis         Ababa         and         the         seaport         of         Assab,         through all-weather          metalled          roads          on          which          public          buses          and          trucks          are
plying  regularly. There are a number of cart tracks crossing 
though  the area which  link  almost all settlements within  the
area
with 
the
metalled 
road.
These
tracks
are
fairly 
trafficable
by 
4-wheel
drive
vehicles
in 
dry 
weather.
The
farmers
generally 
transport
then 
saleable
produce
to 
the
markets
of
koshe
and 
lnseno 
through 
donkeys
on 
marketing 
days
which 
are
fixed 
for
every        week.        From        these        markets        the        produce        is        picked        up        by        the dealers and moved to larger towns through trucks.
General food provisions are usually available in the nearby villages but their shortages are not uncommonly 
experienced. The agricultural inputs like good quality seed, fertilizers and pesticides are virtually non-existent in these
markets. The farmers generally use their own seed and no fertilizers or biocides*. The labour is, however, plentifully available at fairly low rates.
t e .. f t c 1 d e £ ,
Kermxcidet., fungicides ■» nd weedicides.-11-
/
J.              SOILS
. |              Genera I na t ur e
sed i Un* n I
p robab1 
s
V
formed in
d e p o s l t s .
of
The o v • of
I he
soils of the area are
r 1 v mg thick l gn imbr i t e middl ddl-.tto o llautteePPleleisistoctoceenene period)
par t i i \ er
area
L auk ,
stretching towards north and west of the younger ones ( oione proba s ( bly middle
towards extremeext sout rehwm eestern
old      volcanic ash
The    oldest soils
occur in mos l the left
Holocene
period < genesis
. bar a*' t er ist
are
par
1 .
I
is
w h i 1 e found
discussed
A < s a re out
Append l X        11
The i r The main
ext ensive
older soils
consist
/ r .hiu I ar o v ei I y ing eluvial
15 35
P r i sma t t he buried, soil at soils is horizon.
The pro I i I of 15-50 cm
or crumb a 1020 cm
i n detail under lined below.
es of the most thick, very d a i k structured loamy
thick,
greyish brown to black,
t opsoi 1            < A herizon > grey, structureless silty
I ayer
cm
Ir
llltlei
E horizon)
thick, dark brown to to blocky, dense c
gradually decreases
light which 
very dark greyish brown, 1 a y e y illuvial layer
in clay content and fine angular blocky A special character
from the
is abruptly underlain bv a m o tI led,
(B 1 borizoii ) ;
dark yellowish brown, about 1 iu depth.
the abrupt textural change
The other important but ve the same
t differences
> islic
E horizon t
merges with u porous loaiuv 
of t ties<• o the B (
1 <? s s extensive types sequence of horizons  of hor butiztons herebut are
in prope prope rtiers!.lTe hes. E horizon is either
o f older
i h »• 1 s
hoi i
ilue pr obab 1 y underlying Bl no abrupt
z. u n ,   I he
to having been almost completely mixed up 
horizon, or is thin textural change from the
and      b      roken. i f    preseii       t
latter
i n v*ii i a mott1ed 
c olid i t ions, ha v r- pockets ccmen t ed encount er ed li vlilS a 1 l lie Less t han neu t ra I
to slightly have Lot h
A 1 1 mo I
»• V e 11
I
l he
led 
soils
I* e 1 ow
being mostly clay
described above a depth of 1 in,
(^10 c in / A (or E
loam in
text
are very while most <> f
abo v e They are o f
that dep th 
al I noncaIcareous
showing varying to about I m
calcareous material below that depth.
layer, rich in between depths
with ECe less
2 mS/cm below reaction (pH 5.5-
lime nodules and powder, of l‘>0 and 200 cm. All the than 1 mS/cm upto about
is I m
t hat . 7.5)
They have upto about
a slightly 1 III de
u r e .
deep but them are dr a inagc
depth but
A weakly general Iy soils are
dep I h an<1 acidic to
alkal  i n e ( p H     7.5      b.O) below that depth.
and n»*ut ra I
A long
I he       E and             Bt       horizons been eroded
the river,    in a narrow sloping str
• loin i nun t 1 \          1 0.1 III
in text ll re     t hroughou t t he pi <» f » l .
1 P • the soils ow ay and are
They h<iv »• i-12-
The younger
old soils
described
distinct
i 11u vla tion
an illuvial textural
one.
change.
with rare
occurrence
layer of lime accumulation occurring within 1 m depth.
soils are similar to the less extensive above, except that these do not show any and have a structural B horizon instead of
They do not have any E horizon and no abrupt They are relatively loose and well drained 
e of mottles within 1 m depth.
3.2 Main soil t ypes
Based
characteristics,
are identified
are further divided, where
on             differences
in              general
profile
five major soil types, viz. A, B, C, D and E,
to occur in the project area. These soil types
basis of genetlc irrigated
such differences point of view
agricultural
but
use
necessary, into various subtypes on which are relatively minor from
are quite important for their and management.
The spotting
characteristics of these soil their FAO classification (in symbol) are outlined below. A
types         and         subtypes,         as         well         as
parentheses            after detailed chracterization of each
the            soil
type
soil
are described in
type/subtype
is        done        in        Table        3        and        their        typical        profiles detail, along with the important analytical
data, in Appendix V.
So l 1____ t ype __A______ (Planosols)
This
having, grey 
o v e r 1 i e s horizon), within
below the very silty
a siow 1 y so that
about 70 cm
dark coloured Layer- (a 1 b l c
permeab1e, this abrupt
type           includes           all           those           soils topsoil (Ah horizon), a light
E horizon) which abruptly 
clayey layer (argillic B or Bt textural change is encountered 
depth from the soil surface.
general 1y or crumb thickness
10 to 
The Ah horizon 
consists         of         very         dark         greyish         brown 
to black, loams
granular
permeab1e. thick colour water
st agna t t he i r
and
structured, f rom
20       CUI The
has
moderately permeable loams ranging in about 15 to 50 cm. The albic E horizon is about
thick and usually structureless and slowly underlying Bt horizon is generally 15 to 35cm
a mottled, dark brown to very dark greyish brown 
indicative of impededof impeded drainage conditions. The ruin is rapidly absorbed by the topsoil but it
e slow
is understood to 
an
old,
moderat e1y is found surface.
nonca1careous calcareous
for long times permeability.
mo It I ed, dark permeable,
over the E or Bt horizons because of The Bt horizon gradually merges with 
yellowish brown to reddish brown, fine blocky structured loamy soil which 
buried at depths between 80 and 125 These are very deep soils and 
upto about 150 cm. Occasionally, material with some powdery lime or
-- -................CUI from the soil
are    genera    1    1    \ a       few       pockets       of lime nodules are-13-
found  between •list j net zone and with weak
150 cm.
100  and  150  cm depth  but they  commonly  have a of lime accumulation, in  powdery  and  nodular form cementation (calcic horizon), at some depth below
On  the basis of thickness of the topsoil (Ah  horizon) over the albic E horizon  which  acts as a weak  barrier for rooting  of plants, the soil type A is divided  into  the following 2 subtypes:
Subtype, Al Mo  1  11  c PlanosolsJl permeable soils having  25 over the albic E horizon.
Imperfectly drained, slowly cm or more thick All horizon
S ubt > pv A 2          (Eutric Planosols): permeable soils
horizon over the
having albic E
Imperfectly drained, slowly less than 25 cm thick Ah horizon.
Soil
I hos«- L I a c k , but
1 oamv l» row n c 1 <i y textural horizon redd i s h 
125 c m
Type
hav l ng 
(Phaeozens)- a 25
The soils included cm or more thick, very dark
in          this greyish
g r a n u 1 ar or crumb structured topsoil (mollic A
n o o r a
type are b  rown  t o horizon  > silty to
I
layer i to very o a in o r
thm, broken, light grey to greyish brown,
E horizon) underlying the topsoil, followed by dark 
dark greyish brown, subangular
to angular blocky 
silty
clay loam layer (B horizon) with no abrupt
change merges
b rown, depths
between the Ah t(heor EA)h a(nd   or BE)hor and izBonshor ,  izons. The B
gradually with an old,
with an old, dark yellowish brown to 
fine         blocky         structured         loam         soil         buried         at         80 
t o 
1 line
from the surface. These soils upto about 150 cm
or lune nodules may be
These soils are very deep and 
nonca1careous
powdery I 5 () c in 
horizon) nodules between
depth.
d e p t h s .
A
»
contain i n g
and with weak
150 and 200 cm depths.
Depend i n g 
A few pockets with
encountered between 100 and distinct zone of lime accumulation (calcic
abundant powdery lime us well as lime cementation, however, generally occurs
Oil
presence or absence the B horizon, subtypes:-
. M^typc Hl (
s
°f
the drainage conditions, permeability,
E horizon and degree of development of
this soil type is divided into the following 3
. G i<- p h a<-o z vms ) :
imperfectly drained,
with no moderate and dist i nc t
Old, moderately somewhat slowly permeable
or a thin, broken E horizon angular blocky, illuvial B (i.e. -I mottling within 50 cm depth.
we1] to s o l Is
overlying a
B t ) h o r i z o n-lk-
S u b t /J* e            B2
U. uv i c Phaeozems) :
Old, moderately well
drained, somewhat
thin, broken E
blocky. illuvial
mottling within 50 cm depth.
slowly permeable soils with no or a horizon overlying a moderate ungul tr
B ( i . e. Bt) horizon and no distinct
Subtype B3 iHaplic Phaeozeins/ Relatively young, well to 
moderately well drained, moderately to somewhat
slowly  permeable soils with  no  E horizon  and  a weak to  moderate subangular blocky, structural B (i.e. Bw ) horizon, with  no  distinct mottling  within  50  cm depth.
Soil Typ_fC ( Luvisols) - This type includes those soils which have less than  25  cm thick, dark  to  very  dark  greyish  brown, weakly  massive to  granular, loam topsoil (Ochric A horizon)
which           either           overlies           a           light           grey           to           greyish           brown,           loamy 
eluvial           layer           (albic           E           horizon)           which           immediately           rests           on           a
dark 
brown 
to 
dark 
greyish 
brown,
angular
blocky 
clay 
loam
or
silty 
<'lay 
loam
illuvial
(Bt)
horizon,
or
lies
directly 
over
the
Bt horizons, with  no  abrupt textural change between  the A (or E’ and  Bt horizons. The Bt horizon  merges gradually  with  an  old, dark  yellowish  brown  to  reddish  brown, fine blocky  structured loamy  soil buried  below 80  to  125  cm depth  from the surface. These are very  deep  nonca 1  careous soils with  commonly  a few pockets of calcareous material below 100  cm depth. a zone of lime accumulation  (calcic horizon) with  abundant lime powder and nodules may also be encountered below 150 cm depth.
The         following         two         subtypes         are         identified         to         occur         in the project area:-
Subl_yp_^--------01_____ LGLeyic______ Luvisols) :                         Moderately well to imperfectly drained, somewhat slowly permeable soils
with no or a thin, generally broken, E horizon, but
distinctly mottled within 50 cm depth.
VBC __C2 __LAlbic---------- Luyisolsjj. Moderately well drained
somewhat slowly permeable soils with a thick (>
10
cm),           nearly           continuous           E           horizon           and           no           distinct mottling within 50 cm depth.-15-
Soil   _   Typ<--
0   < C he r noz cms£
cm or
< r u in b that
more thick strue Iured,
overlies a
>
very • 1 oarn
dark I
subangular with no general 1y strongly powdery within deep and
b 1 ocky (list inc t
1 oam
These are the dark greyish brown to sandy loam topsoil brown to very dark or clay loam subsoil
soils which have a 25 
to black, granular or
(in o 1 1 i c A horizon) greyish brown, weak 
(c a mb i c B horizon),
mottling within 
cm
depth.
non* a I careous ca1careous
upto about below, with a
depth and calcareous
of lime accumulation 
it S
100
well as nodular fornodul    m (caarlcfiorc mhorizon)
cm depth - Calcic Chernozem-sC. TahelcisceCsheoilrsnozems.
They are
to in
occurr i n g are very
generally well drained with a moderate permeability.
This type includes soils which have a
weak mo 11led overlain greyish
subangular blocky,
clay loam
dark greyish brown to very dark grey, to silty clay loam subsoil (Cambic B
by a 25 35 cm thick, brown to'black loamy topsoil
granular
to crumb,
horizon),
very dark 
- Mo 11i c
G l eysols .
l inper f ec 11 y nonca1careous,
These soils
drained,
but a
are very somewhat
few pockets
100 CID
we 1 1
occasionally found below about
(mol 1ic A horizon) deep, moderately
slowly permeable of calcareous material depth.
The
most
commonly 
soil types
described 
above are
found schematlca11y
textural
sequences of
t <> a n d are
t he
sketched in
Fig 1 .
Loam      li—Vjyj Silt loam or silt
Clay loam fe~=Hi]Clay or
or silty clay loam
silty clay-16-
Table 3: Cllaracteristies of nuxn soil types
“Soil type subtype
and l‘A0 classifi" cation
A L CHARACTERI
Dr linage
Parent
note rial
Hiysio-
C«*phy
GE
Slope
(%)
ER
Soil depth
(cm)
Erosion
and
flooding
STICS Permea
bility
inf iltmtion
rate
(cm/hr)
Present use/
iMtuxal vegetation
2
3
M
5
6
7
8
9
10
A-
Al
(Mollie planosols)
PLAIiOSOLS Old   volcanic ash
Tlat to very gently
sloping
plains
0-2
>200
None to slight sheet erosion
Infierfectly drained;   no flooding
Slow
2-M
Mainly dry-farmed to nuize, sorgTium, red pepper, tet, wheat, beans and lent il; partly grassland used for
grazing
A?
(Du trie
Plansols)
Same us for subtype Al, except that tiie erosion Is slight to moderate -
Bl
B - H1AID7JJE
Old volcanic
ash
(Gleyic Hkieozenc)
Tlat to very
gently
sloping
plains
0-2         >200 Hone to
slight siieet
iv_.ion
Hfcxleiutely
well to
uu(«rfeutly
drained; no
flooding
M derately
slow
5-6          bkiinly dry-famed to nuize sorghum, red pepper, tef, M>eat, beans and lentil; partly grassland used for glazing
B2
(Luvic Biaeozems)
B3
(lliplic llkieozems)
Sane as for subtype Bl, except that these are nixleiately well drained -
’
Subrecent, redeposited (alluviated) volcanic
ash
Gently to
veiy gently
sloping
plains near
the toot of
an escai^«k*nt
1-3      >200    Slight to
noderate
sheet erosion
Well to
nude lately
well dx Mined,-
1Jght tlash
f iooding
tn_in tile
e scarput*nt
ikiring tainy
season; no
inkling
HxJeiute
to
mule lately
slow
9-10
Kiinly dry-famed to nuize, sorghum, red pep^*r and
tef•17
Table 3 (cont'd)
PR0rI
LE CHARAC TERIS Calcareousness
Soil
Sub
Type
Horizon
l.epth
to upper 1)01*12**1 bounduy
Thick
ness
(cm)
Colour wien
moist,
mottling & Fe-ft
segregation
Texture
Structure
& lime segregation
if any
TICS
pH
(1:2.5 soil
water
and ESP*
EC
in 1:2.5 soil-witer*
extrvict (mS/cm)
Special features/
remix ks
12
13
m
15
16
17
18
19
20
21
Al
Ah
E
0
25-50
25-50 (rarely upto 70) 10-20
Bt
35-70
15-35
Bib
90-125
>100
Very dirk greyish brown to black
Light grey to greyish brown; casually
mottled
Birk brown to very dirk greyish brown; mottled
Lurk yellowish brown to redd ish brown; not tied; few le-tti nodules
Loom; rarely
.lay loam
Silt loam to fine sandy
loam
Silty     clay to clay
loom to clay loam; rarely silt loam
Granular   to crumb
Structureless
None di care ous Nonculcareous
Prismatic to angular blocky; thin cutans
Fine angular blocky; tirick cutans
Ncnca lcareous
Honealc. upto t150cm, calc, below; few pockets wxth 1 ime nodules; a distinct
1 inc zone
I*.-low 150cm
5.5-7.0
ESf « 5-10
5.5-7.0
ESP = 5-6
6.0-7.5 (rarely upto
8.0)
ESP = 8-10
7.5-8.5 (rarely upto 9.0 below 150 on)
ESP = 9-10
0-0.1
0-0.1
0-0.1
(rarely upto 0.5)
0.1-0.2 (upto 1.0 in lune
zone)
A  typical  mol  lie  A horizon
A typical albic E horizon, very
distinct from Ah
An argillic B
torizon with abrupt textural change from E to Bt
An old buried
argillic Ixjrizon
with a gradual upper* boundary with Bt; calcic horizon with weak. cementation generally betv*?en 150 arid 200cm d'-pths
A2
Similar to Subtype Al, except that thickness of tix? Ah horizon is <2 5cm,
i.e. the E horizon is encountered at less tlian 25cm depth and the upper
boundaries of all other underlying horizons axe corresponding!'’ si lai lower
Bl
Ah
(E)
Bt
0
25-50
(rarely to 70)
25-60
25-50 (rarely upto 7Q 0-10
Very luK greyish Crown to black Greyish brown
30-50
Btb
80-125
>100
Dark brown to very duk greyish brownf mottled
Birk yellowish tuvjwn to redd ish brown; mottled; few Fe-fti nodules
.oam;    i.uely
.•lay loom
Silt loam to
1ine sandy Loam
Clay loam to silty clay
loam
Loam to clay loam; rarely silt loam
Granular   to crumb
Structureless to weak sub- ingular
blocky Angular to subangular blocky; thin cutans
Fine  angular* blocky; thick cutans
Ncnca lcareous
Noncalcarecus
Honealcareous
Noncalc. upto 1150cm calc, below; few pockets with lime nockiles; a distinct
1ime zone
1*2 lew 150cm
5.5 7.0
ESP s 8-8
6.0-7.5
ESP 8 2-3
6.0-7.5 (ruxely upto
8.0)
ESP = 8-6
6.5-8.5 (rarely upto
9.0)
ESP s 6-8
0-0.1
0-0.1
0.1-0.8
0.1-0.5 (upto 1.5 in 1 uie.
zorie)
A typical nullic A
liorizon
A discontinuous horizon, mj_»tly
absent
An argillic B horizon with no abrupt textural ci range from E (or Ah) to Bt
An old Lxiried argil bi ixirizon with diffuse upper boundary with Bt; a calcic horizon with weak cementation generally between 150 and 200 cm depths
B2
Similar  to  subtype  Bl  except  that  these  are  not  mottled
in
the upper subtoxl, atleast upto 50cm depth
B3
Ah
B
0
25-30
25-30 (rarely upto 50) 50-80
Btb
80-125 (rarely
>200)
>100
Very dirk greyish brown to black
Birk greyish brown to very dirk grey; rarely nettled below SOcm
Birk greyish brown to dirk yellowish brown; nutiled
Loam
Clay loom to silty clay
Loam
Loam to clay loam or salt Loam
Granular to crumb
Subangular to angular
blocky
Cubangu1 ar to angular blocky; thin cutans
Nualcareous Noncalcarecus
Noncalc.,
calc, in pockets; few lint* nodules
6.0-7.0
(rarely upto 8.0);ESP=8-1C
6.0-7.5 (rarely upto
8.0)
ESP = 1-6
7.5-8.0 ESP = 8-6
0-0.2
0.1-0.2
□ .1-0.3
A typical nullxe
A horizon
Probably a cambic (not argillic) B liorrzon; gradual boundary with Ah
lower fxirt of an old Lorled argillic
horizon
i-18-
T.ible 3 (emit‘J)
12
3
$
G
7
8
C -       uivruiir.
Old   volcanic
Cl
(G)ryic
Luvisols)
ash
riat to
very gently sloping
plains
2
>200
done  to  slight slieet erosion
lixJcrately well to uiqcrf rctly li.lined; nc 1looding
lUdcrately slow
M
10
Liiiily <lry-f«uw l to miizc, sorgjiujn, red pepper and let; pn rly grassland used lor grazing
C2
(Albic
tuvisols)
D - (HIJ’WLIJIS
□ 1<I volcanic D                 it Ji
(Calcic Ciieimzcjic;)
- Sane as for subtype Cl, except that these are moderately well drained -
M>lorutely strep to undulating mttyins of plains
>200
f k derate
(*•11 drained
Moderate
sheet to
i i ver
mil ly
I l<»-ling
erosion
hiring r.untic
in lower
|urts only
Mi inly grassland with a (cw species of trees (ntv-lly Acacia) and Luslw's, hiving 60-00% ground cover, used (or grazing; partly dry-f lined
to maize, sorglmm and tef .
E - GLEYSOLS
r.
(Mil I ic Gleysols)
lAibivconr, iv< Icposited lailuviuled) vi Iconic
isn
Vviy gently sloping plain* near tlie loot of an escarpment
>200
'•light
Hidetuicly
sheet erosion
wi'l) to
l.wlrrutely
.low
Ullpei'IrCtly
drained
Subsistence-level rainfed fanning of no inly miize, coig)»uin, tef and red |e|p>r with sone wlreat, barley and beans; a few trees of ntiinly Acacia species.Hip 2
BUTAJIRA PROJECT AJ<EA
SOILS
(AND LAND UNITS)
X
X
>3
| 1 | Level
LEGEND
- Old volcanic ash plain
(<1% slope), very  deep, jjnper
drained,      slowly      permeable,      non-
calcareous,    nonsaline,    clayey    soils underlying   a   light   grey   silty   layer covered  by  a  thick,  dark  coloured loany topsoil (Mollie Planosols).
El Very  gently  sloping  (1-2% slope) ph 
of soils
described un
der napping ur
|  2 
[  Soils
of  napping 
unit
1  but  nainly 
with  a
thin  cover
of
dark  coloured 
Project area
Mapping unit
boundary
boundary
1812m contour line Metalled road
Cart track
River
Tukul/riiLill buildings
loany topsoil (Eutric Planosols).
| 3 | Level (<1% slope), very deep, mndei well to imperfectly drained, somewhc slowly permeable, noncalcareous, nonsaline, loany soils with a thick dark coloured topsoil (Gleyic and 
Lu vic Phaeo zeins).
[3a ] Very gently sloping (1-2% slope) phases of soils described under napping unit 3.
| M | Moderately steep to undulating,very deep, wel1 droinod,
penile^ ble , no/x-'Jlcai'cous , nonsal-Lne
loamy soils with «□ thick, cLu k
cao J oured topsoi_L but -Lbrne zone
within lOOojn depth (Calcic Chernozem
B - Subrecent alluviated ash plair I s I Very gently sloping (1-2% slope), ver
----- -deep, well to moderately well drained moderately to somewhat slowly permeable, noncalcareous, nonsaline, loany soils with a thick,dark colourcc topsoil (Haplic Phaeozems).
[ba~] Gently sloping (2-3% slope) phases of soils described under napping unit 5.Table 4;        Description of soil napping units
Soils
Fhysio-
graphy
Slope
(%)
Erosion
Drainage & flooding
Type/ subtype
Approx. proportion
(%)
Main characteristics
Present land use/natural
vegetation
1
2
3
4
5
6
7
8
1. Mainly level Mollie Planosols
Level plains
<1 (mostly
<0.5)
None to
siight
sheet erosion
Imperfectly well  drained; no flooding
Al
75
A2
15
1
Bl
10
Very deep, slowly permeable, non- calcereous, neutral to slightly acidic, nonsaline, prismatic to angular blocky, dark brown to very dark greyish brown, mottled silty clays overlain immediately above by a 10-20cm thick, light grey silty layer that is covered by a
25-50cm thick, granular to crumb, very dark greyish brown to black loamy topsoil, and underlain by moderately permeable, dark yellowish brown to reddish brown loams at 80-125cm depth.
Similar to subtype Z1 but with less than 25cm (15-24cm) thick topsoil; see detailed description under mapping unit 2.
See under description of napping 
unit 3.
Mainly subsistence leve rainfed   farming   of   uaiz sorghum,   tef,   red   peppe wheat,   barley,   beans   an lentil;   few   patches   und natural    grassland    used for  grazing;  few  very  c trees  of  Ficus  and  Acac species
- do -
- do -Table 4 (cont’d)
1
ry gently oping plains
2a - Mainly very gently sloping Mollie Planosols
1-2         Slight to moderate sheet erosion
Inperfectly drained;
no flooding
Al
8
Mainly grassland with 60-80' percent cover of short and tall grasses, used for grazing; few trees & bushes belcngir mostly to Acacia and F: species; sone patches c farmed to naize, sorgb; tef and pepper.
A2            15
Bl             15
7
Very deep, slowly permeable, non- calcereous, neutral to slightly acidic, nonsaline, prismatic to angular blocky, dark brown to very dark greyish brown, mottled silty clays overlain immediately above by a 10-20cm thick, light grey 
silty layer that is covered by a
25-50cm thick, granular to crumb, very dark greyish brown to black loamy topsoil, and underlain by moderately permeable, dark yellowish brown to reddish brown loams at 80-125cm depth.
Similar to subtype Al but with 
1
less than 25cm (15-2 4cm) thick topsoil; see detailed description under napping unit 2.
See  under  description  of  mapping unit 3.
do
doTable U: cont’d)
1
2   - Mainly level Eutric Planosols
jevel plains
<1 (mostly <0.5)
1 Slight to moderate sheet erosion
Imperfectly drained;
no flooding
A2
60
Al
Bl)
B2)
C2
20
10
10
Very deep slowly permeable, non- calcareous, neutral to slightly acidic, nonsaline, prismatic to angular blocky, dark brown to very dark greyish brown, mottled silty clays overlain immediately above by a 10-20cm thick light grey silty layer covered by a
15-2Ucm thick, granular to crumb (occasionally massive), very dark 
greyish brown to black loamy top soil, and underlain by moderately permeable, dark yellowish brown to reddish brown loams at 80 to 125cm depth.
Similar to subtype A2 but with 25cm or more (upto about 50cm) thick topsoil; see detailed description under napping unit 1. See under description of napping 
unit 3.
Similar to subtype A2, except that these are angular* to sub- angular blocky clay loams or silty clay loams (instead of silty clays) and have a moderately slow permeability and no mottling within 50cm
depth.
Mainly   subsistence   le\ rainfed   farming   of   nai sorghum,  tef,  red  pepj wheat,  barley,  beans  c lentil;   few   patches   ur natural   grassland    usee for   grazing;   few   very trees of Ficus and Ac<= species.
- do -
- do -
- do -1
5
6
7
8
3 - Mainly level Gleyic and Luvic Fhaeozems
Level plains
<1 (mostly <0.5) '
None to 
Moderately well to imperfectly drained;
no flooding
Bl
50
slight
sheet erosion
Very deep, moderately well drained somewhat slowly permeable, nancalcareous, neutral to slightly acidic, nonsaline, angular to subangular blocky, dark brown to very dark greyish brown, mottled 
Mainly   subsistence   le
rainfed  farming  of  na:
sorghum,  tef,  red  pep]
wheat,  barley,  beans  <
lentil;   few   patches   ui
natural   grassland   use<
clay loams or silty clay loams
overlain by a 25-50cm thick, 
for   grazing;   few   very 
granular 'to crumb, very dark greyish brown to black loam top soil, and underlain by moderately permeable, dark yellowish brown to reddish brown loams at 80 to 125cm depth; a thin (<10cm), discontinuous, light grey silty layer occasionally occurring immediately below the topsoil.
trees  of  Ficus  and  Ac<
species.
B2
Al)
A2)
20
20
10
Similar to subtype Bl but well to moderately well drained and no mottling within 50cm depth.
do -
See  under  descriptions  of  napping 
units 1 and 2.
do -
Similar to subtype Bl but these
have less than 25cm (15-2Ucm)
thick, massive to granular, dark to very dark greyish brown topsoil
K'
i
-C
ITable M (cont'dj
1                /2        /3              1’         15
6
7
8
tery gently loping
lains
r
3a - Mainly very gently slopping Gleyic and Luvic Phaeozems
Moderately well to imperfectly drained; no flooding
Slight    sheet erosion
Bl
50
B2
Cl
Al)
A25
20
20
10
Very deep, moderately well drained somewhat slowly permeable, noncalcareous, neutral to slightly acidic, nonsaline, angular to subangular blocky, dark brown to very dark greyish brown, mottled clay loams or silty clay loams overlain by a 25-50cm thick, granular to crumb, very dark 
greyish brown to black loam top- soil , and underlain by moderately permeable, dark yellowish brown 
to reddish brown loams at 80 to 125cjp depth; a thin (<10cm), discontinuous, light grey silty 
layer occasionally occurring immediately below the topsoil.
Similar to subtype Bl but well to moderately well drained and no nettling within 50cm depth.
Similar to subtype Bl but these have less than 25cm (15-2Mcm) thick, massive to granular, dark 
to very dark greyish brown topsoil See  under  description  of  mapping units 1 and 2.
Mainly  subsistence le rainfed  farming  of ma: sorghum,  tef,  red  pep] vfreat,  barley,  beans < lentil; partly  grass!< with 60-80% ground co’ used  for grazing; few trees and  bushes beloi mainly  to  Acacia spec few old  trees of Ficu species.
- do -
- do -
•
- do -
r
(Table 4           (coni’d)
1              12    13                    4
5
6
7
8
4 - Mainly moderately steep to undulating Calcic  Chernozems
□derate!y teep to idulating, irtly 
allied, irgins of
Lains
1 U-16
Moderate
sheet to 
gully 
erosion
Well drained; no flooding in major
part, river flooding during summer in some lower parts only
D
60
Very deep, moderately permeable, noncalcareous, netural to slightly alkaline, nonsaline, granular to weak subangular blocky, brown to very dark greyish brown loams, overlain by a 25-35cm thick, granular to crumb, very dark greyish brown to black loamy topsoil, and underlain by moderately to strongly calcareous loams to fine sandy loams with a disiinct lime accumulation zone (containing abundant powdry lime and lime nodules) occurring within 100cm depth.
Mainly grassland with many trees and bushes belonging to different species; about 60 to 80 percent vegetation cover; relatively gent slopes dryfarmed to maize, sorghum, tef an pepper.
Bl)
B25
Al)
A25
30
10
See  under  description  of  rapping unit 3.
See  under  descriptions  of  mapping units 1 and 2
- do -
- do -
h i
c
iTable 14
(cont1)
5 - Ma ini v
ic Phaeozems
Very gently sloping plains near the foot
□f an escarpment
1-2       Slight to moderate sheet erosion
Well to moderately well drained; light flash flooding from the escarpment during rainy season
B3            70
Very deep, moderately to somewhat slowly permeable, noncalcareous, neutral to slightly acidic, nonsaline, angular to subangular
Subsistence level raj farming of maize, sor tef and red pepper; trees and bushes of n
blocky, dark greyish brown to very Acacia species. dark grey clay loams to silty 
clay loams, overlain by a 25-35cm thick, granular or crumb, very dark greyish brown to black loamy topsoil.
E
30
Very deep, somewhat slowly permeable, noncalcareous, neutral to slightly acidic, nonsaline, subangular to angular blocky, very dark greyish brown, mottled clay loams or silty clay loams with a 25-35cm thick, granular to crumb, very' dark greyish brown to black loamy topsoil.
- do -Table
(cont’d)
8
5a - Mainly gently sloping Haplic Phaeozems
ently    sloping lains near
foot of
i escarpment
2-3
Moderate sheet erosion
. Well to moderately well drained; light flash flooding from the escarpment during rainy season
B3        80
E
20
Very deep, moderately to somewhat slowly permeable, noncaKareous, neutral to slightly acidic, nonsaline, angular' to subangular blocky, dark greyish brown to 
very dark grey clay loams or
silty clay loams, overlain by a
25-35cm thick, granular to crumb, very dark greyish brown to black loamy topsoil.
Very deep, somewhat slowly permeable, noncalcareous, neutral to slightly acidic, nonsaline, subangular to angular blocky, very dark greyish brown, mottled clay loams or silty clay loams with a 25-35cm thick, granular to crumb, very dark greyish brown to black loajiy topsoil.
Subsistence rainfed far of maize, sorghum,tef
and red pepper; few tr< and bushes of mainly 
Acacia species.
- do --29-
4. LAND SUITABILITY FOR 1 RRIGATE_D_ AGR ICU LTURK
4.1              General land Characteristics/qualities
The
soil
mappin
g 
unit
s
describ
ed 
under
sectio
n 
3.3 
may       be
regarded 
as
*
land 
units* 
and 
the
soil
types
(sec.
3.2)
as
’land          t
ypes
y
when 
defined 
also 
w
ith 
respect
to 
cl
imate,
topography,             water             resources             and            vegetation            etc.            The            important
characteristics/qualiIies be 1ow.
of
these
land 
units
are
discussed 
4.1.1 
C
1imate,
growing 
periods
and
ad
apted 
crops.
The            major
climatic
eleme
nts,
i.e.
pre
cipitation 
and 
temp
erature,
as         well
as
the
evaporation 
rates,
have
been 
discussed 
i
n 
section 
2.2. The climatic data show that the period from June to
Sep   t   ember potentlal
is          humid          when          the          precipitation          probably          exceeds          the evapotranspiration and no irrigation may be required
for
dryland             crops,
necessary for a
For other part of the year, irrigation is successful agriculture.
The mean daily
I euiper a t u r cs           range between
17.5 and 21°C during the year which
indicates throughout avaitable. January is
that
there is no limitation for growing crops
the          year, provided that irrigation water is
March       to       June       is       the       warmer       period       while       November       to the cooler period of the year.
The major deciding  factor for cropping  seasons under
irrigation,             however,
is
the
rainfall
distribution             pattern.             The
rainfall data show that the wet period  of the year occurs during June to  September. The seeding  and  harvesting  of crops, as well as lifting  of the produce from field, should  be accomplished during  drier periods of the year, while the wet period  should not occur near the maturity  stages of crops. Keeping  these iacls as well as the temperature regimes in  view, the following two  cropping  seasons during  the year appear to  be the most Pract icable:-
Season 1: June to November
Season 2:               December to May
The important crops which are adapted to the climate °r growing under irrigated conditions are listed season-wise
under Table 5.-30-
Table 5:                    Climatically adapted irrigated crops
Highly Sui t able
Season
crops
Moderately suitable
c r o p s
J une November
Maize (highland varieties) Sorghum (highland varieties) Tef
Phaseolus pulses Haricot beans Sugarbeet
Saf I’ lower Sunflower Red Pepper Onion
Toma t o Barley
Oats Chickpeas Potato Rapeseed Mustard Linseed Cabbage Carrot
Peas
Len til Clovers
Alfalfa Crapes Olive Pomegranate
Soybean
Tobacco
Rice (hlghI and varietles>
December - Wheat May 
Perennial
Citrus Sugarcane
The crops of one season  can  also  be successfully Ktown  m tin- other season  but the expected  yields wi I 1  be ‘Hatively low.-31-
I
The
4.1.2 analyses of
the
irrigation quality
c an be sodicity requirement s to store
p r o b a b I y project
is given
Irrigation Woja river
in section 
wa t er quality _ and ava i 1 ab l I _i_t water which is to be used for'
s t andar<1 s of
safely used for all crops
FAO (Ayers
or carbonate accumulation, are duly satisfied,
about 60 million cubic
be adequate to irrigate
area for dryland crops throughout
2.4. According to and Westcot, 1985),
with little risk of provided the
the water the water salinity, leaching
The proposed  dam is designed 
metres         of         water         which         will
all
s mtable
the year
land of the with an about
150 to 200 percent
cropping intensity.
4.1.3            Topography.            Except           a           narrow           strip           of           land along         the         river         (land         unit         4)         which         should         be         left         for         river
flooding            during            excessive            discharge,
the
land            has            no            steep 
slopes. About 20  ha of the land  have a slope of 2  to  3  percent
and  535  ha have 1  to  2  percent slope, while rest of the land  has
a slope of less than  1  percent. The slopes are linear and  quite
smooth,            offering            practically            no            problem            for irrigation system and working with any kind of farm implement.
layout            of            an 
4.1.4
I he project area
significant hard
roots, part 1y and wets
They generally
by will
t hem.
o f f e r e d silty below
well undernea th
by layer the as
CaCOa Probab1y
A
some which 
topsoil because this layer 4.1.5
and be
minor soils
has ( at
o f
Soil depth and rootability. All soils of are invariably very deep (>200 cm) with no 
pans or any other severe barrier for plant have weakly developed fragipans, cemented 
partly by FezOa, but these are porous softened soon after the irrigation water
to moderate rooting problem is, however, due to the presence of an almost dense few stable pores and occurs immediately 
varying depths between 15 and 70 cm), as an almost dense clayey soil material
(soil t ype A).
Available water capacit y of soils,
r ^present ative soil
sentative            soil            profpriof lesiles werewsearme pled,   sampled,
ana |
for (
2.5  1
Five
in  undisturbed  form,
soils. sported
handed  over to  the National Soils Laboratory, Addis Ababa, determining  moisture contents at different suctions (from pF to pF4.2) to estimate the available water capacity of the
The results for 3 soil types lAl, B2 and B3 ) were bv the laboratory which are presented in Table 14 
1 Appendix f,Jr Die
ln
V). The results indicate an available water capacity upper 1 in of these soils ranging between 90 and 121 mm,
the author’s opinion, are too low. On the basis of-32-
l e X l u i , <1 i f fvr t aval table
.11 i t erent
uiganir mat l er content, structure and porosity <-> 1 soils, the .author estimates the following ranges of
water           in        I he       u p p c r      1     metre           of         soil           co Iumu          Tor soil t ypes:
13 0
120
160
160
180
150
150
160
160
SoiI type;               A 1        A2            B 1           B2            B3           Cl             C2            D           e
The         above            es timat es       give a          range       of 100          t o    180 in m o 1
Aval table
100-
90 -
i 20-
) 20-
140
120-
120-
130-
130 -
water mni) ;
avaitable                water
upto       1 in   dep t h
in different    so I 1       t ype s.         At an
a v er age once
evapotranspiration rale
I u I I y 
3
weeks in 
o  t  her crops
soil
g rowth.
charged with water case
t ypes
of 4 uiin per day, the soils, , can be irrigated at intervals
of soil types Al and A2 and 4 weeks in case without any significant detrimental effects
Soil permeabi I ity and water i_ntakr £pjes
if of o f on
The
4 .  1.6 permcabi 1 i t y 
depend mg
mainly 
of soils
uh I he
from loam to silty claty,o of the substrata have moderate for all soils.
The
varies from moderate texture of the subsoil us The permeabilities
representati in Fig
ve
•>       to 
deter   ui   i    ned 
by
the s 1 1
9 r u
water soils 6.
t tie
little v arlabl infiltration 
tests
for           which           infiltrat
Ilty were
ion
made curves
to siow, it changes
of the topsoil and and are rated as
on      5      sites      of are presented
The basic infiltration rates are also chiefly presence or absence of the silty layer below
t y to
topsoil and the clayey subsoil. In soils having well formed layer and clayey subsoil, the water intake rates vary from
4 cm/hr, while in other soils these generally range between 
and     6     cm     hr,
<Xtreme
except that in some relatively young soils of (he
about I he III os t
southern part (soil type B3) the rates are higher i.e. 10 tin hr: but the latter is probably a temporary phase and 
rates .ire likely to stabilize around 5 and 6 cm/hr other soils because of the expected compaction 
subsidence)
a t r- <| u 11 e
after sorue period of irrigation. These intake
suitable for irrigated dryland crops.
4. 1.7                          Dbiraaiinanagegcand.  and fIloodi    lending. ng.
have          good          external          drainage          conditions is rather impeded in some
permeable silty and clayey layers.
as in land 
rat es
general,
' i h.-iKc.
The soi
i s , in
but
the
internal
s lowly 
‘ ‘>nd i i
ioiis due to water stagnat ion above
ones due to the presence ol Perched water table
these layers are likely-33-
to occur periodically and exist for sufficiently long periods to
affect crop  growth. Such  conditions may  presently  be even 
useful
for
some             dry-farmed,
shallow-rooted             crops
(like
tef)
which          cun          utilize          this          water          efficiently          during          dry          period          after the rains, thus having positive effects on their growth. The
proper
irrigations are groundwater Therefore, expected under dry 
selection 
of crops of utmost
is quite
no problem
deep,
of
under these importance, ranging from
aeration for
situations and careful The general level of
about 20 to 30 metres, deep plant roots is
wea t her
conditions and if excessive
irrigations are avoided.
The whole
is
to           be           considered           for
irrigation 
above            the the river
development
area             which lies quite
high (about 4 to 15 metres)
riverbed and is quite safe from seasonal flooding by
Surface             ponding by rainwater may occur in small
patches           (which           serve           as           micro-basins           in           the           area)           but           these occupy less than 2 percent of t tie total project area.
4.1.8 project area have adequate amount of
to 4 percent. They
Soil f e r t i1 i t y and pH. All soils of t tie a considerably thick (15-70 cm; topsoil with organic matter varying from about 2 percent have a high base saturation and a favourable
PH a
this
t hat few cases,
remains around neutral upto at least 1 in depth; in only 
rarely soils noted 9.0 of
dept I). upto 
in to
the pH was noted to be between 7.5 and 8.0 within Below ] m depth, the pH may go upto 8.0 (very 
8.5) which will not affect nutrient availability of
genera 1.
Below a depth of about 150 cm, the pH was
be
around 8.0 in most soils and rarely was as high as
showing an alkaline substratum;
normnoralmal
plants,
1 n
but it is too deep for roots general, the nutrient contents of the
soils as wellaass requirements
their availability
are adequate to meet plant
under
s in a 1 1
1 ow
and medium levels of inputs. Use of
high
doses of fertilizers may, however, be necessitated under a
level of inputs.
will |              •   *_
topography) Percent
the
upto soil
are 1
noncalcareous ui depth.
there
generally
mass is exist
c  ° n t a i n i n g 
a
distinct
nodules,
between
Le
associated depths of
4.1.9 L i me Con ten t. All soils (except a few which not be considered for agricultural development due to their
with a lime content of 1 to 3 Below this depth, too, the major part
noncalcareous to slightly calcareous but a few pockets of calcareous material
lime nodulefsewor lpow ime denodul   ry lune es or.  powdery lime. The occurrence of layer containing abundant powdery lime and many lime
with weak cementation, is rather common 
cm .
o
f
150 and 200 cm. It is, however, too deep to
■importance for the growth of common crops.-34-
4.1.10
Salinity and sodicity or acidity. A1 1
soils <-> t electrical
s us pens ion
I he project area are nonsaline with the maximum conductivity at 25°C (EC) of 1:2.5 soil-water
being about 0.2 mS/cm upto 1 m depth and 0.5 mS/cm
below,           except          that          just          above          the          layer          with          excessive          lime
(            lime            zone)
it
occassiona11y            approaches            1.0            mS/cni.            Most
commonly, however, the EC remains below 0.1  mS/cm upto  1  ui and less than  0.2  mS/cm below this depth. If converted  to  ECe (EC of the soil saturation  extract), the values remain  quite below the level at which common crops start suffering from salinity
effects, at least upto 150 cm.
The          ESP          (exchangeable          sodium          percentage)          of          the          soils is          below          15          throughout          the          profile          which          has          no          detrimental
effects           on           soil
stability           or           sodium           toxity           to           plants.           The
exchangeable           acidity,           i.e.           aluminium           and           hydrogen,           is           also           low and has no harmful effects on plant growth.
4.1.
11 
Soil
workabilit
y.
Most
of
the
soils
possess
granular
to 
crumb 
st
ructure
while
a
few
ones
have
weakly 
massive
to 
granular
structur
e
in 
the
surfa
ce
layer.
They 
are,
therefore, easily workable and would require low-power machinery
or only  draught animals for tillage. They  are capable of coming to  a good  wilth  even  with  one or two  ploughings. In  fact, they do  not require any  preparatory  tillage for dryland  crops except for removing  the stubbles of the previous crop; the minimum tillage technique would  probably  be the most practicable on these kinds of soils. Under wet weather conditions or after
irrigation moisture sowings. way that season.
topsoils, t hose
1) ue effected
to a high degree of
by high organic
soils
u 11 i v a t ion.
give
long
rice
are incapable of being But the
n            »v*** v           _  - Period after flooding and, hence, the
may be duly compensated.
however, these soils would remain above workable level for somewhat long periods which may delay 
This can be managed by planning cropping systems in a the sowings are completed before the onset of wet
particle aggregation in matter content, however, properly puddled for rice
slow permeability of the subsoils would advantage of holding water in topsoils for considerably 
1 ow
workability for
having
g c a n u1 ar
4.1.12 Slopes
topsoi 1 s, the land 
tu
the
and
land,
quite
Part
have
of
sii g hI
S o i 1 ero si pjr Most of
of less than 1 percent
have no significant erosion hazard, having more than 1 percent slopes do,
moderate
by virtue permeab 1 <•
A sma11 however ,
degree of sheet erosion hazard due toexpected  waler runoff from the higher parts. In  soils having slowly  permeable layers at relatively  shallow depths (type A2) and  occurring  on  mure than  1  percent slope, a slight slumping  of topsoil may  casually  occur after heavy  rain  storms, while on oilier soils, no  or very  slight erosion  may  occur upto  2  percent slopes due Io their relatively high water infiltration capacity.
4.2              The classifi < at ion sys t em
The             land 
suitability             classification 
refers,
for
the
purpose of this report, to  the evaluation  of different tracts of
land  for growing  specific crops with  irrigation  under defined 
levels           of
inputs.           The           classification           is           done           in           terms           of
relative            suitability            of
land            on            qualitative            basis
rather
than 
its
absolute
(quantitative)
suitability,
the
latter
being             beyond 
the scope o 1* this report.
For           this           purpose,           three           levels           of           generalization           are considered as follows:
At the highest ’Suitable’ for
capital letter The term
g rowlng inputs
level,
an 
’S’
’Suitable’
a certain crop under irrigation and 
the land which is considered irrigated crop is denoted by the
and that ’Not suitable’ by ’N’. implies that the use of land for
a defined 
level
is considered to be economical
t he
use of
uneconoiuica1 cond i t ions.
At into t . e.
the second
’ Not under
level,
suitable’ land 
the present
is
, while considered 
socio-economic
3 SI ,
classes by
S2 and S3,
the suitable land 
using an arabic numeral suffix, on the basis of whether they are
highly
suitable
land ’N’
on t he
suitable
fact o r s permanently not
suitable, respect ively.
moderately suitable S iid 11 ar 1 y ,
’S’ is divided or marginally 
the unsuitable
is basis
(due wh i ch
divided into 2 classes,
of to may
whether economic
change
i.e. N1 and N2, the land is currently not
considerations i n near future)
or other u r is
suitable respectively.
A        highly        suitable        land        (SI)        means        that        the        land        has no or only a minor limitation for growing a certain
crop  and  that the net
remain  above a minimum
suitable
land            (S2)            has
which in aggregate are
expected 
net
returns               will
returns from that use will high level. A modern t e 1 y 
a limitation or limitations moderate for the use and Un
be moderate. The
marginally____________ suitable land  (S3j has somewhat severe
limitations for the use so  that only  low net returns
can              be              expected; negative net returns may be encountered.
occassiunal
crop 
failures
or-3&-
A t the and  S3 sin a I 1
lowest         level,         the         land are subdivided into
let ter
suffix
after
suitability classes S2 subclasses by adding a
the class number,
1    ndicaI    i    ng    the productlvity.
kind          of          limitation          affecting          the          land If more than one limitations are
faced,           a           double           letter           suffix           is           used           representing the two most important limitations.
The          limitations          affecting          the          land          use          arc          taken          us the           class-determining           factors           which           are           discussed           in           the           next section.          The          crop          requirements          are          assessed          with          respect          to          the
class-determining             factors             and             are             matched             with             the
respective
iharncter         istics         or         qualities         of         the         land         units         to         reach         at         the final land suitability classification.
4.3              Class d» t <-riu i ni_i_ng _f ac tors Hunit.it i ons )
X
chararteristics/qualities selection            of
review discussed 
of
the
in 
important
chapter                    4 
land allows
land suitability:
the            following            4            factors            as            class-determining            for
liootability of soils
Drainage
Basic water infiltration rates
Soil erosion hazard
Climate (somewhat too cool for a few crops)
These factors are graded for the purpose of matching with the crop requirements as in Table 6.-37-
Tabl^ 6: Grading and definition of class-determining’ factors
Fac t or
Grades
Doo tab i11ty
Def initions Drainage
Bas i c infi 111 at ion
Rate (cm/hr)
1  Deep rooting unrestricted
2           Deep rooting somewhat rest ricted
3           Rooting restricted immediately below the plough layer
Free                                            3 S1ight1y
impeded
Moderat c 1 y (periodic al 1y highly) impeded
3 6.5
>6.5
L r u s i ’'.
None S] l»jh Modei
In light of the above factor grading, the land units are classifi
as in Table 7.
__
Classification of land units with respect to different grades of
class-determining factors
(The grades given in parentheses apply to 15-30 percent of
the total area under the unit)
Land Units
Fat. tor s
1            1 a              9                  3              3a              4              5              5 a
I j tv
2(3)
2(3)
3(2)
1(2)
1(2)
1
1
1
inage
3
3
3
2
2
1
1(2)
1(2)
p'*1 1 11 r;‘l ion rate
2
2
2
2
2
3
3
•1•
LI ’OS ion
1
2(3)
2(1)
1
2(3)
3
o
3-38-
4.4          Crops and_input levels considerej
All            crops
listed            us            climatically            suitable            fur
the
project area under section  4.1.1  are considered  individually  for assessment of land  suitability. These crops may  be grouped  as follows.
Foodgra.ins:
Vegetables: Pulses
Oilseeds :
Orchards :
Sugar crops:
Other crops:
wheat, oats, r ice potato,
barley,               maize,
tomato,
sorghum, pepper,
cabbage, carrot, peas
haricot
beans,
red phaseolus
lef, onion,
pulses,
chickpeas, lentil
sunflower, safflower, rapeseed, mustard, linseed, soybean
citrus, grapes, olive, pomegranate sugarbeet, sugarcane
tobacco, alfalfa, clovers
It had  not been  indicated  in  the terms of reference whether the land, after irrigation  development, will cont inue to be managed  by  the present farmers at the same low level of inputs or it will be state owned  and  managed  at high  level of inputs. In  any  case, it may  be speculated  that the following -lianges are bound  to  occur after the irrigation  system is * ntreduced:
i                        The           field           layout           will           be
distribution ar ea .
of
irrigation 
revised           to           allow           proper water over the cropped
i i i                    The        size        of        parcels        to        be        maintained        will commensurate with the land use type, i
be finally
e. smaller
size (about smallholders
0.2        ha;        for        cultivation        with        oxen        by of land and larger size (1-2 ha)
t he
f o r
mechanical cultivation on the state-owned land.
iii)              Minor local to ensure fields.
levelling will be don uni form dis t ribut i on
e, where necessary, of water in the
iv) The farmers will be properly  guided  to  adapt to  the methods of applying  irrigation  water to  their fields and  there will be sufficient water control to  avoid 
over-irrigations
adjoining fields.
and 
excessive
seepage
toward 
the-39-
Keeping  in  view the above quoted  basic changes which are likely  to  occur for the irrigated  use of land, the probable two future levels of inputs and management are defined below.
M t • d i u in i npu I s_ level : by small land holders, labour with
Sem i
commercial, cooperative farming 
using animal traction and family a medium capital intensity, sufficient use
of fertilizers, sufficient but no
pesticides and in tercultural operations
adequate drainage of excess
rainy season,
be casually levelling of
control of erosion.
Hi gh input s technical
somewhat erratic excess i ve
fields or
improved seed,
for weed control
rain water during
irrigations which would or delayed, no precision 
terracing of sloping land for
I evel £ labour,
Commercial             farming             by             state-employed 
using             mechanical
power,
deep 
pIough  i ng about 50 precis ion
and  mixing  of the subsoil with  topsoil upto cm depth  in  soils, of restricted  rootability, land levelling and terracing where necessary,
or contour ploughing  for dryland  crops and  construction 
of level benches for rice on  very  gentle slopes: high 
capital seed,
intensity,           use           of           proper           amounts           of           improved 
fertilizers
and 
biocides, crops,
careful timely 
irrigations
avoiding             over-watering             of
disposal
of
excess           rain           water           from           fields           through           properly           aligned 
and 
duly 
spaced 
shallow               ditches
and 
sufficient
intercultural operations to control weeds.
4 • 5            Crop___ requirements
The            lowest            grades            of            the            class            determining            factors Squired          by          the          selected          crops          for          relatively          high          production          at 1,,e dium and high levels of inputs are considered as in Table 8.-uo-
Table 8:         Crop requirements in terms of factor grades
Factors
•
Crops
Rootability
Drainage
Erosion
Infiltration
rate
Med. Level
High
Level
Med. Level
High
Level
Med. 
Level
High
Level
Med.
Level
High
Level
i) Foodgrains
Wheat
Barley
Maize
Sorghum
Tef
Oats
Rice
ii) Vegetables
Potato
Tonato
Red pepper
Onion
Cabbage
Carrot
Peas
iii) Pulses
Haricot beans Riaseolus pulses
Chickpeas
Lentil
iv) Oilseeds
Sunflower
La-f flower
Rapeseed
Mustarxl
Linseed
Soy Lean
v ) Orchards
Citrus
Grapes
Olive
Porregranate
v i) Sugar crops
Sugarbeet
Sugarcane
v ii) Other crops
Tobacco
•^lfalf
a
-levers
2
2
2
2
2
2
3
1
2
2
2
2
2
2
2
2
2
2
1
1
1
1
2
1
1
1
1
1
1
1
2
1
2
2
2
2
2
3
2
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
2
3
2
2
2
2
3
2
3
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
1
2
1
1
2
2
2
2
?
2
2
2
2
3
2
3
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
1
2
1
1
2
2
2
2
2
1
1
1
1
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
2
2/3
2
2
1
1
1
2
2
2
2
2
2
2/3
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2/3
2
2
2
2
2
2/3
2/3
3
3
3
3
3
3
1
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
1
3
3
3
3
On
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3-m-
4.6 Assumptions made
The
land 
suitability 
classification 
is
based 
on 
the
following 
assumption
s,
in
addition 
to 
the
assumed 
changed 
conditions mentioned under section 4.4:-
i)             The irrigation water will be adequately and regularly
supplied            throughout relevant crops.
the            growing            periods            of
the
ii) The cropping  seasons will be adjusted  in  a way  that sowing  and  harvesting  times fall in  relatively  dry months (see section 4.1.1 for cropping seasons).
iii)
There will be sufficient control on  use of irrigation water and  excessive percolation  of water (except the leaching requirements )will be avoided.
iv )           The land suitability 
land conditions with groundwater table is
depth for at least
system is introduced Uncontrolled             excessive
is assessed under the present deep groundwater table. The
expected to remain below 2 m 20 years after the irrigation 
under normal dryland cropping.
irrigations may  create perched 
water table at about 150  cm depth  due to  the occurrence of a calcic horizon  below this depth  which probably  has somewhat slow permeability. This will necessitate a drainage system to be installed at
about 150 cm depth.
v)             At the high level of inputs, the surface of sloping
land  will remain  effectively  covered  with  crops during  rainy  season  to  minimize soil erosion  and  all input requirements (including labour) will be
adequately met with.
v i)                     On         soils         having         slowly         permeable         silty         and         clayey layers         below         the         topsoil         (soil         types         Al         and         A2), planting         of         orchard         trees         will         be         done         after         making about        1        m        deep        pits        of        1        in        diameter       and       refilling them        with        the        loamy        topsoil        material        at        high        level        of inputs,         but         without         making         such         pits         at         the         medium level of inputs.
Rice        planting        will        be        done        after        maximum        puddling        of soil surface at both levels of inputs.-42-
1.7 Land s_u j t ab 11 i t^ class i f i cat ion
B
y 
matching
the
class-determining
charac
t   er   i   s   t
l   cs   /qu<il
i   I   i   es   of
t he
land units (Table 7
) with the
crop 
r   e»j   u   l
remc   n   i
s   (Table   tijt
the land s
uitability classificat
ion 
reached is presented in
that the land units which are composed of more than one land suitability assessment characteristics of the
table 9. It should be clarified here
being assessed for suitability are
soil types (see section 3.3).
The
given in the table
is
based 
on 
mos
t
important soil types
cov
ering 70
percent or more area occur in
assessment
s i in p 1 i c i t y . (average)
regarded comprehensive
of any
uni   I .       Some minor soil the        ma l n      t ypes
een         given          here
types wh
ich
associ ation which has
This, suitability 
homogeneous information 
with
not
have
for
a di
fferent
b
the
sake
of
however,
also
represen t s
I he
uvera1 1
of the respective land unit
for practical purposes.
which may be
For more
regarding 
the              proportion              of
different
land           suitability           subclasses
in           any           land           unit,           the           reader
is
referred to Table 4 and Table 12 (Appendix III).
Table 9:              Land suitability classification* for different crops
_ _____________ at medium and high 1 evels of i npu t s__________________________
(The limitation symbols used as suffixes are:-
r - rootability, d - drainage, e = erosion,
i - infiltration rate, c climate (i.e. somewhat tuo 
land units;
low temperatures)}
ae
M  d_i uro level of inputs
1
1 a
2
3
3 a
40
5
5a
crops
1 > Foodgrains
Wheat
S2d
S2dc
S3rd
Si
S2e
S 3 e / N 1
S2e
S2c
Barley
S2d
S2de
S3 rd
SI
S2e
S3e/Nl
S2e
S2e
S 1 a i z c
S2d
S2de
S 3 rd
SI
S2e
S3e/Nl
S2e
S2e
hum
S2d
S2de
S3 rd
Sl
S2e
S3e/Nl
S2e
S2e
Tef
SI
SI
SI
SI
SI
S2e/Nl
SI
SI
Oats
S2d
S2de
S3rd
SI
S2e
S3e/Nl
S2e
S2e
lit i ce
S3ci
N1
S3ci
S3ci
Nl
N2
Nl
Nl
1 i ) Vegetables
'°tato
S2d
S2de
S3rd
SI
S2e
S3e/Nl
S2e
S2e
Tomato
S2d
S2de
S3rd
SI
S2e
S3e/Nl
S2e
S2e
bed pepper
S2d
S2de
S3rd
SI
S2e
S3e/NJ
S2e
S2t
Onion
S2d
S2de
S3rd
SI
S2e
S3e/Nl
S2e
S2e
L U b b a g p
S2d
S2de
S3rd
SI
S2e
S3e/N I
S2e
S2r
’ arrnt
S2d
S2de
S3rd
SI
S2e
S3e/Nl
S2e
S2e
S2J
S2de
S3rd
SI
S2e
S3e/NI
S2e
S2e“43-
1
la
2
3
3a
5
5a
iii) Pulses
Haricot beans Fhaseolus pulses
Chickpeas
Lentil
iv) Oilseeds
Sunflower
Safflower
Rapeseed
Mustard
Linseed
Soybean
v) Orchards
Citrus
Grapes
Olive
Pomegranate
vi) Sugar crops
Sugarbeet
Sugarcane
vii) Other crops
Tobacco
Alfalfa
Clovers
—
S2d
S2d
S2d
S2d S2rd S2rd
S2d
S2d
S2d
S3dc S3rd S3rd S3rd S3rd S2r S3dc S3dc S3d
S2d
S2de S2de S2de S2de S2de S2de S2de S2de S2de S3dc S3rd S3rd S3rd S3rd
S2re S3 de S3de S3d S2d
S3rd S3rd S3rd S3 rd S3rd S3rd S3rd S3 rd S3rd S3rd S3rd S3rd S3rd S3rd S3r S3rd S3rd S3rd S3rd
SI
SI
SI
SI
SI
SI
SI
SI
SI
S2c S3dc
SI
S2d S2d
SI
S2c S2c
SI
SI
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e S3ec S3dc
SI
S2d
S2d
S2e S3ec S3ec
SI
SI
S3e/Nl S3e/Nl S2e/Nl S3e/Nl
S3e/Nl S3e/Nl S3e/Nl S3e/Nl S3e/Nl S3e/Nl
S3e/Nl S2e/Nl S3e/Nl S3e/Nl
N1
N1
S3c/Nl S3e/Nl S3e/Nl
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e S3ec S2ec SI
S2e
S2e
S2e S3ec S2ec SI
SI
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S3ec S2ec
SI
S2e
S2e
S2e
S3ec S2ec
SI
SI
k) High level of inputs
land units
Crops
1
la
2
3
3a
**
4
5
5a
Foodgrains
Wheat
Barley
Maize
S° ghum
r
Tef
Oats
Rice
S2d
S2d
S2d
S2d
SI
S2d S3ci
S2d
S2d
S2d
S2d
SI
S2d S3ci
S2d
S2d
S2d
S2d
SI
S2d S3ci
SI
SI
SI
SI
SI
SI
S3ci
SI
SI
SI
SI
SI
SI
S3ci
S3e/Ml S3e/Nl S3e/Nl S3e/Nl S2e/Nl S3e/Nl
N2
SI
SI
SI
SI
SI
SI
N1
S2e
S2e
S2e
S2e
SI
S2e
N11
la
2
3
3a
4
5
5a
ii) Vegetables
Potato
Tonato
Red pepper
Onion
Cabbage
Carrot
Peas
iii) Pulses
Haricot beans Riaseolus pulses
Chickpeas
Lentil
iv) Oilseeds
Sunflower
Safflower
Rapeseed
Mustard
Linseed
Soybean
v) Orchards
Citrus
Grapes
Olive
Pomegranate
vi) Sugar crops
Sugarbeet
Sugarcane
vii) Other crops
Tobacco
Alfalfa
Clovers
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S3dc
S3 de
S2d
S3d
S3d
S2d
S3dc
S3dc
S3d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S3dc
S3dc
S2d
S3d
S3d
S2d
S3dc
S3dc
S3d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S3dc
S3ac
S2d
S3d
S3d
S2d
S3dc
S3dc
S3a
S2d
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
S2c S2dc
SI
S2d
S2d
SI
S2c
S2c
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
S2c S2dc
SI
S2d
S2d
SI
S2c
S2c
SI
SI
S3e/Nl S3e/Nl S3e/Nl S3e/Nl S3e/Nl S3e/Nl S3e/Nl
S3e/Nl S3e/Nl S3e/Nl S3e/Nl
S3e/Nl S3e/Nl S3e/Nl S3e/Nl S3e/Nl S3e/Nl
S3e/Nl S2e/Nl S3e/Nl S3e/Nl
N1
Ml
S3e/Nl S3e/Nl S3e/Nl
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
S2c
S2c
SI
SI
SI
SI
S2c
S2c
SI
SI
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
|S2e S3ec S3ec
SI
S2e
S2e
S2e
S3ec S3ec
S2e
S2e
The    classification    is    done    in    terms    of    land    suitability subclasses. The subclass suffixes (smal  e
represent only the most
tw Imitations are almost oi equal uipo suffixes have been used.
" Tic classifications are
applies to areas having 
the last one to steeper (M slope; b flooded parts.
double-letter
(<6%) S gullied or seasonally-4 5-
4 . K Land suitability mapping units
units for-
input s.
which is
idea of
land unit
i ns I ance ,
res tncl
to improve its outputs can be suggested.
The table 9 gives suitability classification of land 33 different crops at medium and high levels of
The c1 ass l 1 ication was considered at subclass level important because, at the first instance, it gives an 
what production levels could be attained on a certain at different levels of inputs and, at the second 
it indicates what kind of limitations are expected to its productivity so that the specific measures required
The
specific              management
requirements
of
different
land  suitability  classes, according  to  the limiting  factors are given  in  the next section. The suggested  measures should  be adopted  keeping  in  view the Land  Units map  (Soils map; and  table 9. For the purpose of presentation of land suitability maps,
different           land           units           having           the           same           production           potential,
i.e.
having  the same land  suitability  class for the selected  crops al any  level of management and  inputs, are grouped  together. Consequently, 5  land  suitability  mapping  units (I to  V) at medium Level of inputs and  4  units (1  to  IV) at high  level of inputs are delineated  on  ’Land  Suitability’ maps (Map  3a and  Map 3b  respectively) at a scale of 1:25,000. These mapping  units are described  with  respect to  their potential, areal extent and component land units in Table 10.
Table 10:                Land suitability mapping units, their extent and component land units
Map
Unit
Descript ion
Extent*
(ha)
Component
land units
Medium level of inputs (Map 3a)
I
Land with high potential for most
448
irrigated crops but a moderate
(31 )
3
Potential for orchards
II
Land with a moderate potential for*
241
most irrigated crops and orchards
(93)
3a,5,5a
III
fund with a moderate potential
883
tor* most irrigated crops but a
(19)
1 , la
low potential for orchards
IV
fund with mainly low but some
401
‘Moderate potential for most
(0)
11 1 * gated crops and orchardsMap 3 b
BLHAJ1RA PROJECT AREA
LAUDSUITABILITY FOR IRRIGATED AGRICULTURE (High level of inputs)
I
/
/
8
I] Land with a high potential for most
irrigated  crops ' J -iv-nn-ia nnd  a+od r>mrv-»rode»Q srnaHt remdprtato p "tnhi  hi gh  o'
potential for orchards.
Land    with    a    moderate    potential    for most irrigated crops and orchards.
Land with a moderate potential for most irrigated crops and moderate to low potential for orchards.
Land   with   very   low   or   no   potential lor irrigated crops or orchards.
lbee fable 11 ior land suitability for individual crops)
Project area boundary Mapping unit boundary
1812m contour line Metalled load
Cart track
River
Tukul/small buildings-mG-
Land with a very low or no** potential fur most irrigated crops and orchards
High J_evel_ of inputs (Map 3b) Land with a high potential for most
157
(85)
669
irrigated crops and moderate to high                                                         (104) potential fur orchards
11 Land           with a moderate                potential for
20
most      irrigated crops ill Land            with a moderate
and orchards                                   (20)
potential for
1284
most irrigated crops and moderate                                                            (19) to low potential for orchards
IV Land with a low or no** potential
157
for irrigated crops or orchards                                                                  (85) * Extent is given for total area of the unit and (in 
par en t lies i s) for the area lying below 1512 m elevation.
** Applies only to gullied and seasonally flooded areas.
The assessment of these mapping units fur individual crops in terms of land suitability classes is as in Table 11.
Table 11: Crop-wise assessment of land suitability mapping units
3,3a, 5 5a
1, la,2 4
Land suit, map units
C r ops
Medium inputs level
High inputs level
I
______ (Map 3aj________ _______________ (Map 3b)
Il 111 IV V ' I Il II I IV
Wheal
Bar ley 
SI
S2
S2
S3
S3/N
S1
S2
S2
S 3 / N
Mu i z
e
SI
S2
S2
S3
SI
S3/N
S2
SI
S2
S3
S2
S2
Sorghum
Tef
SI
S3/N
SI
S2
S2
S3
S2
S2
S1
S3/N
SI
SI
SI
SI
S2
S3/N
S3/N
S2/N
S2
Oats
SI
SI
S2
S2
SI
S3
S3/N
S1
Rice
S3
N
SI
S3/N
S3
S2
N
S2
Mato
SI
S2
S2
S3/N
S3
N
S3/N
SI
S3
Toiuat o
SI
S2
S2
S3
S2
S3/N
SI
S2
S2
S3/N
S2/N
S3/N
N
S3/N
®   pepper
ed
si
S2
S2
S3
S2
S3   N
‘J n i o n 
Cabbage
SI
S2
S3/N
SI
S2
S3
S2
S3/N
SI
S2
S2
S3/N
S1
S2
S2
S3
S3/N
SI
S3
L ’<*rr o I
S1
S2
S2
S3
S3/N
S2
SI
S2
Peas
S2
S3/N
S3/N
SI
S2
S2
S3
S3/N
SI
S2
S2
S2
S3/N
S3, Ni
-47-
I II III IV V
1 II III iv
Hari
Phus
cot beans
coins pulses
Si
S3
S3/N
SI
S2       S2
S1
S3
S3/N
SI
S2       S2
Chickpeas
S3
S3/N
Si
S2       S2
Len t i 1
S3
S3/N
SI
S2       S2
Safflower
Rapeseed
Mustard 
Linseed
Soybean
Citrus
Grapes
Olive
S u n f I ° w e r
SI
SI
SI
SI
SI
SI
51
52
S2
51
52
S2
51
52
S2
SI
SI
S2
S2
S2
S2
S2
S2
S2
S2
52
53
S3
51
52
S2
52
53
S2
SI
SI
S2
S2
S2
S2
S2
S2
S2
S2
52
53
S3
S3
S3
S3
52
53
S3
S3
S2
S3
S3/N
SI
S2       S2
S3/N
S3/N
S3/N
S3/N
S3/N
S3
S3/N
SI
S2       S2
S 3 / N
S3
S3/N
SI
S2       S2
S3
S3/N
SI
S2       S2
S3/N
S3/N
S3
S3/N
SI
S2       S2
S3/  N
S3*
S3/N
S2
S3       S3
S 3 / N
S3
S3/N
S2
S2       S3
S3
S2/N
SI
SI        S2
S3/n
S3/N
S3
S3/N
S2/S1
S2       S3
S3/N
Pomegranat e
S3
S3/N
S2/S1
S2       S3
Sugarbeet
Sugarcane
Tobacco
Alfalfa
Clovers
S3
N
SI
S2       S2
S3
N
S2
S3       S3
S3
S3/N
S2
S3       S3
S3/N
N
N
S3/N
S3
S3/N
SI
S2       S3
S3/N
S3
S3/N
SI
S2       S2
S3/N
(sia ll
root         .le^ter              suffixes)         for         subclass         designations         in         table         9         (i and      c      *      4-I      *-t      y»      d      =      drainage,      i      =      infiltration      rate,      e      erosion land         |r              ‘lunate)         wherever         they         become         important.         Since         class         SI
4.9 Specific management requirements
The important factors that are expected to limit the land productivity, as discussed under section 4.3, are:-
i)  Rootabi1i ty
ii)      Drainage
iii)           Water infiltration rates
iv)     Soil erosion
v) Climate
o                               These factors are indicated as limitation symbols
Su bcl
as
lrtS
n°
S4 r.nificant
limitation,
it
is            not            defined            at
reader S p  eve^ by  using  any  symbol of limiting  factors. The
°f iiinit this report should  be able to  identify  the major kinds
USe type**  *°llS °ffered  hy  a land  unit to  the given  specific land 
°f the ]•
for 1
from the limitation symbols used. The severity ? t tions is indicated by the arabic number suffixes
1a
mode lSS distinction (i.e. SI:                                            no significant limitation,
Su|||ewh;ti
era ^e                 degree           of
• »‘Vere 1 iin i t at ions ) .
limitation           or
limitations           and           S3.1
-48-
sl >r« i -
J1
3 o m ‘ * i cult
UHproV.-ucn 
improved            «•>
of these limitations can
oral techniques, a few ones need major
involving high costs while the others may not
any known means. The possible measures required 
dcsevere these limitation are given in the following
offset l ab • H
o I’
Si/ecifi* measures required 
be offset by adopt ide 1 and
be to
the major limiting
Inuit j ng fa*. I <a -
R o o t a b k 1 l t s
S y m b o 1
factors
Actual I i in i tat ion offered to plant
g row t h
1              Restricted rooting due to somewhat
dense subsoil
Specific measures requ ired
i ) S uhsol 1 iug ii) Deep ploughing 
to mix-up the subsoi1 and t ops O1 1 materials to 
about 50 cm
depth.
Ih a i it a e e
.1
Temporarily             impeded drainage              conditions below the topsoil
• luring rainy season and immediately after heavy irrigations due to slowly permeable subsoi 1
i)
Subsoi1lng
ii)
Avoidance of
heavy irrigat
ions; J ighIe r
irrigations at
short er
intervals
in)
preferabIe
Quick 
of excess
disposal
rain water the
fields ; or
shallow small
drains at
about 60 cm
depth for tha I
l
Too high rate of
i n fi1 t ru t ion
causing excessive
loss  of  i  r  r  i  g  a  I  ion water from the
t opsoi1
i)
purpose
Puddling of
the t o f > s < > i 1 
ifor rice
cu 11 i va t ion)
as much as
POSS l b I e“49 -
Soil erosion
Loss of relatively fertile topsoil and slow decrease of soil depth
Climate
c
A       little       too       cool for a few crops
ii Avoidance to disturb th»* denser, s1uw1y permeable
deep ploughing or
sub-soili n g .
i)        Loca1 
level 1i n g
ii)       Contour ploughing gentle
of upto 2 ®<.
iii) Terracing 
steeper slopes
iv) Cultivation of crops
providing good vegetalivc cover
rainy season
None pract ical
on slopes
on
during
♦ This limiting factor is important for rice cultivation 
only. Nice cultivation in the area is not recommended due to poor puddling characteristics of the topsoil, not quite favourable climate and risk of further drainage unpedeuce.-50-
cONCiJiSiOhS AND.R^^MjEhH^TlONS
Main Conclusions
Base
ri?5
ources
. oiic 1 us j ons
o f
can
on I h<? foregoing; study and evaluation of the land Butajira project area, the following main 
be drawn:-
Out of 2130  ha of land  area surveyed  for the project, about 1572  ha (74  percent) are moderately  to  highly suitable al both  medium and  high  levels of inputs f«»i cultivation  of most crops adapted  to  the climate under irrigated  conditions; an  additional 401  ha (19  percent) are also  suitable*  for that purpose under high  level ol inputs.
Out of the total suitable*  land, only  143  ha lie below the proposed  elevation  of 1812  ui and  can  be served  with irrigation  water through  gravity  channels; the rest of
the       land       will       require       pumping       to       a       maximum       height       of       12 
m above this elevation.
i i i )        The          crops          which          are          moderately         to          highly          suitable          for
cultivation         on         most         of         the         project         area         (1572         ha)         at
both medium and high input levels include wheat,
bar 1ey,
maize,
sorghum, tef
oats,
carrot
potato,
tomato, red 
pepper,
onion,
cabbage,
peas ,
sunflower,
safflower, rapeseed, mustard, haricot beans, phased us pulses, (lovers; at high inputs level, suitable for orchards of grapes.
linseed, chickpeas, lentil, sugarbeet and 
mos t area is also
About G8‘J ha of land  is moderately  to  highly  suitable also  for- raising  orchards of citrus, grapes, olive and pomegranate, as well as for alfalfa and  tobacco, in addition  to  the above-mentioned  crops, at both  levels d  inputs, while it is also  moderately  suitable for soybean and sugarcane at high level of inputs.
sdt | I™
l            SUitable’ here refers to moderat e 1 y u> e but not marginally suitable land.
and     highly-51 -
V
t             most           important
limitations
faced 
to          high
productivity 
of          the           project
land         are         restricted
. ..h  i 1  i t v  and  periodic*  unpedence of drumai’e, hot!) due to  the presence of about 25-50  cm thick, somewhat jepse and  slowly  permeable layers immediately  below the
topsoil
(at 15-50 cm depths).
These limitations can be
offset             or desevered by special cultural techniques (see
section 4.9). importance
area.
Other soil
limitations
are of minor
and        apply          to       relatively small part of the
VJ )
The present level of groundwater is very  deep  (below
20-30  in) and  no  drainage problems due to  the
groundwater          are          likely          to          emerge          until          at          least          20 
years
after
the
irrigation 
system              is
introduced,
v i i )
A         hard 
layer
containing 
many 
lune
nodules
and 
provided  the land  is used  for dryland  crops (i.e. not
for rice) and irrigation water is judiciously applied.
rooting  zone (i.e. between  150  and  200  cm depths) which is not important for crop  growth, if the land  is normally  used, but may  act as a temporary  barrier for deep  percolation  of drainage water and  affect drainage of the overlying  soil (and  even  cause its salinization}
abundant
powdery 
lime
frequently 
occurs
below
the
normal
crop 
if
the
soils
are             heavily 
irrigated;
the
latter
i)
condition         may         necessitate         a         drainage         system         to         be         laid at about 150 cm depth.
5.2              Specific recommendations
The          land          is          presently          cultivated          by          poor          farmers          who 
are mostly ignorent about the tillage techniques. neither have the resources
They
to make any input on land
nor        they        probably        know        what        improvement        they        can        do        in 
their present
farming system.
Any farm implement if
they  ever have is so  crude and  indiginous that it must
now be regarded  as obsolete. There is much  more a need 
of providing  the farmers with  proper implements and  of
dispersing  technical know-how among  them through  an 
efficient
agricultural extension service than 
just
introducing           an           irrigated           farming           system           in           the           area.
Ie fact
is that a good farmer with proper implements
^un produce 2 to 3 times the present production from
i° same land under rainfed conditions with only a bit
’•lore labour in improving sowing, interculture and rain ^atep management practices. The government should pay 
special improvements c °untry.
attention to this aspect to make general in rainfed agriculture throughout
the-52-
11 '
1 I is project t he i r water are
and
understood area
fie Ids is to
are and be
that
not
t he used
present farmers
to artificial watering of
in 
the
they would not know when and how much applied to a certain crop unless they 
proper Iy
d i s t r i b u t
t rained
in that. A proper water control
i on
Io
avoid untimely irrigations
system should therefore, be organized 
and over-waterings by the
farmer, as the fields local
sci ect ed.
w e 1 1 by
levelling
as to ensure its uniform spreading selecting proper size of parcels
according to the method of lirigat
A     dis Iincl
ad v a ntage
of introducing irrigation in 
over and ion
L he
area field 
wou  Id be
in
one
is
and data, June
of growing more than one y ear.                For the
required to select the
crop on the same purpose, a systema atic
rese a r c L seasons
c 1 im.it l c be from that
crop rotations.
the two most practical seasons
to November and from December
With
best
the
ciopp ing aval lab le appear
to May,
t o 
s o 
sowings
rela     ti     vely 
dry
two
crops even
and harvestings may be periods (most
are listed in Table 5).
in a y be done
adaptable crops
Some short-season 
during f o r t h e
seasons like thrice
vegetables and t e f caand   n  tef can possibly be grown 
adjusted, harvest i ng crop and accump1ished
a year The multiple
(and lifting sowing of the
within a
if sowing times are properly cropping would also imply that
the produce) of the previous
next crop short period
will        have        to        be of 4 to 6 weeks.
T i iu e 1 y 
advice as well
of
of
inputs,
the produce and
harvestl ng 
the
operations etc.) will have
as proper infrastructure (supply agricultural storages to take immediate care
appropriate machinery (o expedite to be provided by
government to achieve that end.
IV )
The
I he
area
most agri
is
impeded season 
topsoil drainage spac i ng avoid
important factor which is cultural production under
the internal soil drainage which would 
expected to limit
i rr iga t i on tn the
remain 
for significantly long periods
long periods during rainy 
due to water (cspec i al 1y
1 i nes should
stagnation immediately below the in soil types Al and A2) .
at aboutabout    60   60 cm depth with 
preferably be
such
S h a 1 low 25-4 0 m
to
maintain e d surface
condi tions,
to remove excessive
and drain it off towards
laid by the government or some open ditches should be
rain water from the soil t he river.
v )
The cropping patterns
defined for the area
high delta crops*, like rice and sugarcane
'^lh high water requ i renien t s .
under
so as
irrigation should be
to strictly exclude (which
*
1 r o p E-53-
are
not quite suitable even c 1 iinat ical ly for the area);
other*ise, prob 1 e in s be laid
mov emen t
p r e s e 11 c e
their cultivation will add to the drainage
and may necessitate another drainage system to 
at about 150 cm depth below which the downward of water is usually
of a somewhat
restricted due to the slowly permeable layer
V 1 )
containing lime nodules.
The area of suitable land  winch  can  be irrigated  Ly gravity  channels from the proposed  dam has only  a small extent (143  ha), while water will have to  be pumped upto  about 12  m for irrigating  the remaining  part of suitable land. The economics of pumping  water for that
purpose             and             sustainability             of
the             proposed             pumping 
system          should          be          carefully          assessed          before          designing          of the irrigation dam.
The
anticipated 
high-lntensity 
of
cropping 
under
irrigation  would  imply  an  accelerated  rate of nutrient
extraction  from the soil. A need  for using  fertilizers
to  get high  production  is likely  to  emerge within  a few
years           after
irrigation.           The           farmers           are           not           presently 
familiar            with            using 
fertilizers            and 
it            may            feel
cumbersome        to        them        if        they        are        suddenly        asked        to        do 
that.
The
fertilizer
use
should,
therefore,
be
familiarized          among          them          soon          after          the          introduction          of irrigation system.
viii)          Relatively          high          humidity          to          be          created          in          the          field 
environments           with           irrigation           is
likely           to           invite           quite
a number of plant diseases and  pests, as well as new
types of weeds. This may  necessitate the evolution  of
new              disease-resistant
crop              verieties
and              use
of
biocides.
For that purpose, the plant protection
service           should           be           activated           along           with           the           irrigation extension and research.
Growing  of vegetables, pulses and  orchards of citrus, olive, grapes and  pomegranate will probably  be the most promising  commercial land  uses in  the project area
after
irrigation.               Necessary               markets
and 
transportation 
arrangements        may        have        to        be        developed        for        that        purpose, to provide sufficient incentives to the farmer.
f rom that
laboratory analyses of the soil samples collected a few soil pits exposed during soil survey reveals
the exchangeable sodium percentage (ESP) is
somewhat critical in most soils and could affect their Permeability and internal drainage after their
°ng-term irrigated use, say after about 10 years. Ut 1 Consequences can be avoided by adding 2 to 3-54-
tons/ha of gypsum
after       every       4       to       5 
otherwise            be            made ^ypsuin requirements
and  leaching  with  excessive water years. A reassessment of ESP should after about 5  years to  determine the of all important soil types.■
-55-
Ayers,
ajbI westcot,
I n’ iEati oo.
Rev. 1
FAO,
LITRATURE CONSULTED
D . W . , 1985. Water Quality for FaO Irrigation and Drainage Paper 29,
Rome.
Il
rx
n k un»n
R.»     1972. Soil Soils bulletin
L a h o r e .
Forming Processes in West Pakistan,
No.
.            Soil Survey of Pakistan,
p e |uuw,
E 1985. Guidelines for Soil Profile Description.
Transfer and Training Handbook No. 1. WRDA, Addis Ababa.
De Puuw, E.»            1986. Technical Memorandum on Preliminary Results
of                Reconnaissance Project Area. WRDA, Addis Ababa.
Soil
Investigations
in                Butajira
FAO-UNESCO, 1974. Soil Map  of the World, Vol. I Legend.
UNESCO, Paris.
FAO, FAO, FAO, FAO, Landon,
1977. Guidelines for Soil Profile Description. Land and 
Water Development Division, FAO, Rome.
1979. Soil Survey Investigations for Irrigation.
Soils Bulletin 42. FAO, Rome.
1961. Agro climatic Data for Africa, Vol.
Production and Protection Series No.
19b5. Guidelines: Agriculture.
•1 . R. ,    1984 . Agriculture London.
Land Evaluation for FAO Soils Bulletin 55.
Booker Tropical Soil Manual. Internatlonal
Ltd. ,
FAO
1 . FAO   Plant 22. FAO,    h oiin .
Irrigated
FAO, Rome.
Booker Bloomsbury house.
Makln, m.J. et
Rift Ministry Division,
Survey Staff,
al, 1975. Valley,
of Surrey.
De ve 1 opmen t Ethiopia. Overseas
Prospects in the Southern
Land Resources Study 21. Development, Land Resources
No - 18. I>. C .
1951. Soil Survey Manual. USDA Handbook
U.S. Department of Agriculture, WashingtonA P P E _N_.P __I._C_ E _S-57-
A pp£NDlX
1 ;
The
area
descri
METHOaOLOGY
methodology         adopted         fox'         soi s l         survey         in         the         project bed as follows.
A e rial
1:40,000 
t aken 
j>holographs with an approximate average
Ln 1971-72 were used as base
survey, 
(j e 1 i n e a t
a fl er
ions
enlargement to about 1;20,000 scale,
on
the aerial photographs were made by 
arras
t he drawn distan c
hav ing 
help
on
of
t he
di fferent
a mirror photographs
photo
st ereoscope.
so
e
of
densit y points
l ransect far as
of tmainly 
450 m about 1
1 i nes it was
the
for
between the lines,justifying an per
old exact
possible,
scale < • I maps lor soil
Pi e i i hi i nary separati ng 
patterns, tones and relief, with Transect lines were then 
as to keep an approximate ground observation
20 ha, keeping in view that some sharp Ficus trees) should be along or on the
location of the observation sites. As the existing tracks extending almost
perpend i cu 1 ar 1 y 
from        the        river        were        used        as        transect        lines,
T he
boundar v
1 l ne was
by t he
t hrough drawn i n approx i mu t e in that part.
of the marked 
concerned plane
t he
areas falling
partly with irrigation
tabling,
A
area
o b s e r v a I
below 1812 ion density
below and above the 1812 m contour the help of a contour map provided 
engineers and partly by tracing few additional transect Lines were
m contour line so that an of 1 per 7 ha could be obtained
The
the author
Mr.
assist am e
and 
of
Steven Paris,
Muhammed, 
t w o w e e k s
field 
f r o in 
t wo 
t echni cians, Mr.
the
work was curried out
Water
as a joint venture FAO Soil Expert, with
Ainaha Getachew and Mr. Resources Development Authority,
by the All lor
at p •'
dur i
a PPi*ox ima t e
ng 
d
November (7 20^, of 4 50
1986. to t he
The
Observations were
made
1  ines. 
istances
h\ was
At
each
1 Jiyers
u*e.ins of uu 
r  e > t r i c t e d 
J Gf CaCO
studied
observation site, auger upto a depth of
above that depth by accumulation.
500       m       along       the       transect soil           profile           was           studied 2      m,      unless      the      auger      ing some       too       dry       or       cemented 
following characteristics
1
or m
ant recorded on a standard soil profile description
i)
ii     i
'•i )
t v )
aee feat ures:
Physiography, micro-relief and slope (by Suunto l - 1 i nouie i   e r )
breserr      t
natural
Coding or erosion hazard
land use (and the crop vegetation (type and cover
e sence ot surface stones or rock
stand if present) and )
outcrops1’’
PROJECT ABx^
SOIL  OBSERVATION  AND INFILTRATION TESTS S
NOV., 1986
%
fefife
I
IDA^ ,
/ •*>
i
3'
// /’’V >.
8
LEGEND
No    of    observation    site but/27
Auger    observations    to about 2m depth
Soil pits described and sampled for lab. analysis (anger observations within the pits to 2.5-3m depths) Soil pits described and sampled, with infiltration tests in 3 replicates around each pit.
¥
• ->
n
Project area boundary Hipping unit boundary 181?ni contour J inc Metailed road
Cart track
River
Tukul/cjiull buildings
8
.w° q.
T
Tha* d soi ' charac
layers around pits were
cteristics.
laboratory of
Ababa. uhm.------U--ndi ----s-t-ur---be-- d
-59-
2 m depth.
sampled for
The analyses Water Resources
Al 1 important horizons from the laboratory analyses of important
were carried out at the Soils Development Authority, Addis
| core
depths        ofof’ a fewa        few        most
moisture characteristics
samples were also taken at varying representative profiles to study their
(pF curves) and bulk densities which 
was same us
all and pres*
done at the sites were
discussed in observation j
sampled, as
en ted (Map 4) ;
After
• National Soils Laboratory at Addis Ababa; the also used for making water infiltration studies Appendix III. A map indicating the location of points and the sites of the soil pits described 
well as the water infiltration study sites, is at an approximate scale of 1:35,000.
the            field            work,            delineations            on            the            aerial
.          tographs          were          corrected          in          accordance          with          the          observations
made and  were finalized  as the boundaries of soil mapping 
units.. These boundaries were transferred  by  hand  onto  a topographic map. of 1:25,000  scale which  was prepared  by 
enlarging  a 1:50,000  scale map  published  in  the year 1975, after some minor corrections noted  during  field  work. This map  was finalized  as ’Soils’ map  by  assigning  appropriate symbols to  the
mapping units.
The areal extent of the mapping units was
calculated  by  cutting  and  weighing  method. The composition  of the mapping  units was estimated  from the field  observations and general patterns of occurrence of the main  soil types. The land suitability  for different crops was assessed  by  matching  the climate data and  other land  characteristics with  the crop requirements estimated  from personal experience of the author and from some related literature listed herein.-60-
WATEW INFILTRATION A_ND HYDIIALILIC_CONDIICTI_V1TY
Af .p£Nl)lX 11 • Ila.
'
*                STUDIES
W a t er infiltration studies
jja-l.
4 jiDporta"
1
representative
Method. soil types
ve pits with
The infiltration studies were made on (Al, Bl, B2 and B3) around their 5 
3 replicates for each pit site. The
also           sampled           for           detailed           laboratory           analyses,
About
p‘
04 to 
ts we
n 
4 K
hours
before
prewetted circular
by area
l he c — approxim hour’s bushes tests
embanked
a t e 1 y repeated against
were then
const ruct ing
of about
area with i
10 cm o f <
fillings.
disturbance by animals or man.
the infiltration tests, each site was about 20 ciu high dike around a
1 m diameter, and by carefully filling water time and again, so that leaving 
water standing over it after about one
The sites were protected by thorny
The inf i11 rat ion 
carried
inf litrometer as described
out with the in FAO,1979.
help 
of a doub
le ring
The         water         used         for         infiltration Woja       Hiver       with       an       EC       of       0.28       inS/cm ib         to         be         used         for         irrigation.         The 4         to         7         hours         depending         on         the different           soil           types.           The           instantaneous cumulative          water          intakes          recorded          during against the elapsed time in Fig. 2(a) to 6(a).
tests         was
that
of
the
at       25°C.
The
same
water
tests
were
continued 
for
near-steady 
state
reached 
for
water
intake
rates
and 
the
study 
are
plotted 
One out of every 
soil type
of an about infiIt rat i on part intact. infiltration in Fig. 2(b) to
150 site
tests 6(b) .
three replicate sites studied for any was excavated after the infiltration test in the form
cm long and 40 50 cm wide trench cutting the by half on one side and leaving the rest half
The wetting profiles of the soils after were then studied and sketched as presented
3
-•                 Concl us i ons . The following conclusions may be
rawn         from         the         infiltration         tests         for         the         4         soil         types studied.
i)         T h
the           3Verage
infiltration          rates          for          the          first          hour          and 
„        _        basic        infiltration        rates        of        the        4        soil        types        were <is toll ows :-58-
. . uildwater table (from existing open wells) v i u
Polile Characteristics:
I | hickn<-ss and sequence o 1' so boundaries
i J horizons and their
11 J
El) r each horizon,
colour and mottling by Munsell’s Charts
texture by feel method consistence (when dry, moist and sliuclui*-, culans, slickensides porosi t y
Ke and Mn segregations, if any
Soil Colour wet )
etc.
proportion         of         rock         or         mineral         fragments,         if         present root distribution
electrical conductivity at 25° C (1:2.5 soil
wa ter)
pH (1:2.5
soil water), partly using electronic pH
meter and
partly by colour indicator method 
carbonaIe
content by effervescence with IO”® IIC1 ,
lime powder and nodules
cement at ion or pun format ion if any
other special features like microbial activity, krotovinus, charcoal or pottery pieces, tongues of contrasting material etc., if present.
i i i      Drainage,
inferred 
from               colour,               mottling,               moisture
content and microrelief. i v i     Per  meab  i  1  i  t  y 
inferred from texture,
porosity              and
st r uc t ur e of
the most restricting horizon.
.ikout i 11 addition  to  the auger observations, 17*  soil pits of
rp li‘e«-en( Ll X *" 111 size and  1.5  m depth  were exposed  at
11,4111 soil iVe s^tes to  make detailed  profile studies of the
Io  study  yPes- Augerings were also  made at the bottom of pits
h        a  >
U|   er
1           ie            Profiles       upto        3 
in        depth        as        far        as        possible:
ings were frequently restricted by the presence of
4
described by De Pauw
(19RG).-61-
S o i1 Type Soil Type Soil Type Soil Type
__ Al_______________Bl_________________ B2_______________ B3_____
Mean Range Mean Range Mean Range Mean Range
1st hr. nv.
.nftHrat .on 
ra tes (cm.hr)
7.2
2~12
14.1
12-24
16.0
12-19
22.1 
17-29
Basic
in fi 1 irat io.,
rates (cm/hr)
3.2
1.2-5.5
5.0
3.5-6
5.0
4.5 -5.5
9.1 6.511
The       average       depths       of       total       water       intake       (cm)       by       the       1 
soil types after 5 hours were as below:-
Mean of all replicutes
Range
Soil Type Al
2 1.6 6 35
Soil Type B1
22.3 11-38
Soil Type B2
23.2 20-26
Soil Type B3
26.6 19 33
The        maximum        depths        of        water        penetration        after        the        tests were as follows:
Soil Type Al
( B u t / 1 0 )
Soil Type Al
(But/84)
Soil Type Bl
(But/126
Soil Type B2
But/121)
Soil Type B3 
(But/88)
1 n f x i t
rat ion
)
322
223
313
4 50
323
De Pth of
Pent -
r ^io
n
-in)
85
45 
130 
85 
75-62-
AVI
l'lie
1 II f ‘
moisture d l s I r i b u t i o u in the
itr.it ion tests may be interpreted
The    downwa    i    d 
movement of water
profile after as follows:
is restricted by 
j>resence of
E horizon.
It stagnates for some t just above* tins hut izoii. This permeability of the E horizon.
J uuit ing horizon in the soi1
t be the
ime
u nd
points Th j s
r ype
The vert the Bl
spreads lateral Iy 1 o the slow
specially a
Al .
unrest r i <.
ic.il movement of water is limited  also  by horizon  of soil type Al but the water passes ted by this horizon in soil types Bl and
The       wetting       profile       of       soil       type       B2       is       normal       with       a uniform lateral and vertical water movement.
The subsoil immediately  below the topsoil (plough layer) upto  about 70  cm in  case of soil type B3  is somewhat loose and  has a moderately  rapid permeability  compared  to  the lower part; there is
more             lateral             movement             than             vertical
until
that
depth. The lower subsoil (lit horizon) is relatively 
• Iitisc and has somewhat slow permeabi i a t y . H >4 r * i u £ ii ’ conductivity studies
1
o one
Hut/to.
represents a
1 50 i in depths area surveyed. laying out a
i >* 1 i ub i I i i y of through further
T  h  e  s soil
The
tudy for hydraulic conductivity was limited only
profile
st u d y bur led
of soil was made 1 oaruy soil
type Al at observation  site No. for the lower subsoii which occurring between about 100 and
with similar characteristics in most part oi the These soil depths are especially important toi
drainage system in the area if required. The the results, however, needs to be ascertained 
studies on a few sites.
The determinations of the hy’drau 1xc
|,y using inverse auger hole metho, ‘ es
“1      s,,‘1 Manual (Landon, 1984'' previously saturating “I' u> auger hole with water (after P
between the depths for which the hy i the "i ""•’•sured and measuring the heights °
'    -Booker
, n the
nielhod relies on conductivity is
surface above intervals. The
ana
oI
° f auiier “°le
waler at certain times (ht;
S ?hC ^0 5 times radius of the
falhSt time (t) in
‘.I.,,
15
. * 
il
O, w.wml i. 
u °<1 from the slope (tan ot 1 °
-                            X II) ..
paper and the hydrau t- curve, which Li °°1 jno         s-»iuo_>  „ , .
s
T ’-1f»pt»O3 
02 1 P«»"
J pAq aq-j
00   I   4   hoqg
Un
nn o.
TI
'Aitp/ni <]£'() 3rl haaM)aq  umn[oc> jios <*M4 s T <1) si rr r sn A q
- v
,JOT I^Toj
Ap P/mM>up) f T QJ •> q ) y H r e.n
f ;firij p| tf 1 KJ 1 s
-pg-Intake rate (em/hr')
Cumulative intake (cm)
Fig. 2(a): Water intake curves of Soil T,pe Al- Mollie Planosols (obs. sire: But/10)
d(cm) =
20 40
Fi g- 2(b):          Wetting profile of replicate tbl (But/ ^-P) after the infiltration test on Soil Cype AlIntake rate (.cm/'hr)
Cumulative intake (cm)
0              60           120            180            240         300           360         420
Tine elapsed (min.)
Fig. 3(a):  Water intake curves of Soil Type Al-
-
Mollic Planosols (Obs. site But/84)~
80    60    40    20      0      20    40    60     80
d(cm) = Q n o
i           1           1          1          A         1 . - i                1_____ i
q 4'
(D
O
fU
20 1
40 -
1_ __
2
E
i; ,
x:
■p
60 -
80 -
a  100-
Aj.’V',’Ah *hor*izpn:         *.•
E horizon
Bt horizon
----------  Horizon boundary
|?. ‘    < [ Wetted soil
0           Centre of the        ring a -    a’      Inner ring
b -    b’     Outer ring
d            Distance from            centre of the rings
Fig. 3(b):            Wetting    profile    at    replicate    site    *b*    (But/84) after the infiltration test on Soil Type AlFig. *4 (a ): Water intake curves of Soil Type Bl-Gleyic FTiaeozems (obs. Site: But/126)
(a,b and c are 3 replicates)
d(cm) = i i_______ I----- 1-----L---- I----- 1-----1---- 1---- 1---- 1
100 80       60 U0 20            0      20 u0 60
80       100
a  ~ a’
Inner ring
b - b1
Outer ring
d 
Distance from centre of the rings
p ■
* Wetting p
ll
rofile of replicate b  (But/126)
jfter the
infiltration test on Soil Type El
Cunulative intake (cm)Intake rate (.ciik/Yvr')
Cumulative intake (cm)
Fig. 5(a): Water intake curves of Soil Type B2-Luvic Phaeozems (Qbs. site: But/12ij
(a,b and c are 3 replicates)
Wglting    profile    of    replicate    'c1       (But/121) g/ter the infiltration test on SojdlY£g__§£Fig. 6(a): Water intake curves of Soil Type B3-fiaplic Hiaeozems (obs. site: But/88)
(a,b and c are 3 replicates)
b - b’ Outer ring 
d            Distance from centre of the ring^
6(b): kjgtting profile at replicate site 'c' (But/S?) gfter the infiltration test on Soil Type B3
CumulaXjve intake (cm)Ill :
SOIL GENESIS
A^h
from volcanic
The
t
soi Is
ash
pel 1od
III os t 1 y o Mak lii i
of the project i deposits of
which overlie
pl<-1: l u< •(•lie
latter are
i accord j ng 
area are invariably furmed probably middle to late
Still older Ignimbrites; the
acidic         and         inter-bedded         with         tuff
el al 1975).
* *
and 
------ -..J pumice
Before the ignimbrite material
was but per 1 <>d de v »• 1 op
ied must
into
under the younger volcanic ash material
a very long 
1 ijiiJu
Soil
w111 < h
per i ud:i t
Joust- b j
u
now
have
a
with occurs
passed to get the former highly weathered and friable, dark yellowish brown to reddish brown strong fine blocky structure and thick cutans,
at about 1 m depth. Then, during later
‘ owp.ic ( ,♦ J
he volcanic avol  ctivicaty niccontributed a cover of rather considerably thick layer of ash which, with time, got
and developed into the upper about one metre thick
B antb' soils now used for agriculture.
The important processes which appear to have played 
part 11* i
development of soils from the overlying ash are:-
leaching or removal of salts by rain water and
simultaneous           subsidence           of           the           land           surface           effected by compaction of the loose ash material;
h                                     accumulation of the removed Ca and HCOa ions as CaCOj        in powdery as well as nodular form in the deep,          weathered ignimbrite and its cementation in some parts by alternate wetting and drying;
removal of clay and sesquioxnies from layers (eluviation) and their accumulation in lower layers (illuviation);
development of structure in the ^ ^ ^g’i(
Ub
from coarse prismatic to fine blocky, resulting b 
in
p bv 
alternate swelling and shrinkage during wet periods respectively;
v
accumu1 at i on 
topsoil; and 
plant roots
Ve getation cover of grasses and trees,
of organic matter (mainly 
formation of tubular pules Ly 
and animal bodies under
in         the decay       ui
j dense
i n t eriu i x i ng with the
the topsoil
t hrou »h by 
i
,ll<JVemen t o f
1,1 r * hworins
h r1 a kmun
(i n some underlying 
through plant roots, ass
soil animals and termites
(1972) as
parts) illuvial
biotic a<
of        the        eluvial        layer layer as well as with
I‘l v i ty ‘ (i.e.Xbreaking     • j ~           « ociated with up and down 
including especially the a process described by 
Homogenization" by which-70-
dafferent
soil
layers
get
incorporated with organic matter);
removal
of
topsoil
material
through 
intermixed and
sheet erosion  or
slumping 
from
higher
parts
and 
its
deposition 
in 
lower
parts
eifected 
by 
removal
or
deterioration
of
of
Fe-Mn 
nodules
the vegetation cover; and
reduction,           mottling           and           formation 
in           the           subsoil           due           to           intermittent           stagnation           of rain water below the topsoil.
The
to a few
..rigioal
i uiw ediatcly
above-went 1o n e d 
different
kinds
differences
after
i n 
t h e
ash
gently coucave
several posslb 1 y about 25
undulating aleas.
thousand
topography
one dominant type of very deep,
soil forming processes gave forth of soils, depending mainly on the
microrelief. The land surface, deposition ended, probably had a
with distinctly formed convex and The processes i to v continued for a long time
years) and resulted in the formation of noncaicareous soil with
to 40 cm thick, dark coloured loam to silt loam topsoil
Ah  horizon)
struct ureless , 
eluvial 30 cm Silty lower
layer thick,
clay 
which was overlying a 10 to 20 cm thick,
ligh grey silt loam to very fine sandy loam
(E horizon), followed immediately below by a 15 to prismatic to blocky, dark brown coloured illuvial
layer (Bt horizon) with decreasing clay content to 
(Bt
d e p t h s
ignimbri t ic
' unccntrat i on 
gradual 1y soil
leached
(upto 2 cm
at
1 i me
old
The
Nodules
1-5      to c o o c a v e dicker
H) q                     •
and
and 1 oamy
of gravel
merging with the 1 to 1.25 cm occurred in the
size) at varying
3.0 metres, parts and 
de v e1 opment
depending on the microrelief shallower in convex parts),
buried, depths.
form of powder, depths of about (i.e. deeper in 
Similarly, the
1 •»*'--* I 4. Mi
of
LlitZ £. dll U DI. 11M 1 A
1 
1
the E and Bt horizons probably occurred
•'
The
°°k
r  .. l j 1 .. 1
 ace Soil
up surface from erosion. „ . ..— ------------------------------------------- I.t was then probably followed by
•          '’‘Ulively          dry,          period          which          deteriorated          the          vegetation 
i Eiually concave sites and thinner on convex sites.
development of the soil profile described  above under a leaching  type of moisture regime and thick ve"gevet^ateiion  ationcover which effectively protected
1>r one’ t
? Uc
rr
eiJ Uce(i
e
^speci.ny  f
water erosion. washed down
‘ ^sequent ly
o   the
to the concave sites renaei
convex sites, and rendered the soils
•—
The topsoil of the convex sites was
the concave sites rendering - the land
almost flat.
This also resul e 1 □
1 ‘‘tekness
of the Ah horizon (about 15 to  “
c
the Ah horizon (about 15 to cm o 
f
- o n v e x
sites aend   s aind   ncrinc easreed asone ed one (upt(upt  o abou     o abou   i   „ly „ , i
sites.                     These differences are
r ear  1  f r v
|, r VC(I
"sent
e °ncav e
«rlj
r i0 U‘O
r 1 J e f
area and are not otherwise explainab <--71-
A f|.i the above remained some
,,
considerably thick cover
process <.,f flat l. nlll(. of reJ
moister parts in the orinmdk ’
j  t > <- oucavc-
’
4
lung tiin< - The illuviation process reused amount of rainfall but
. (1t in these parts to promote the Jro organ isms in t lie process of 1 
Ol vegetation persisted was slowed down due to 
1 he soi1 moj
(
s ure kuS
IH
e
E horizon were intermixed 
m Ji de r i >' claycy .. or no
iur lit horizons and,
/silly clay 1oam
E horizon was formed.
consequent 1 y , to clay
activity of plant roots comugenizaiion. So, some with the overlying An and 
a soil type with loam) Bt horizon and a
The impeded
drainage conditions due to high
i n
t hc-
rat liei giano 1 aI to low rainwater and even perlods . reflecIed mottles, sur f a< e. of more 1 
■I mm
abs or p ( i on
topsoil but limited discharge of the absorbed water (im permeabi1ity of the clayey subsoil (Bl horizon). The -
probably used to stagnate mostly above the B( horizon,
p o s s i b 1 y
above some E horizons,
The reducing conditions thus created
by the prtehesence of strong brown to very 
f requ«-n t 1 y
encountered within 1
The
reducing conditions had been
than 2 meters which 
is evidenced by
s i z ed
dark loamy
grey t soil.
The
nodules formed by segregation o yellowish or* olive
area have remanjcd of ram water by the
for considerably long in I he soils are
dark grey ui dep Hi from the
prevailing to depths the presence of 2 to 
of Fe anil Mn, and of Coloured mottles in the buried
overgrazed Vegetat ion towards the
J  percent.
r| ‘’-se to the
"‘•cizons ;ui(j
aC0 accumulation,
thick loamy w d -ve loped a'
area wh i ch cover.
river, so
along the river had in the past been probably accelerated erosion by water due to reduced 
It now has a gentle slope which increases that the slopes close to the river exceed 
Same is
river
e ven a
the pattern of soil truncation. The soils have lost almost all of their Ah, E, Bl
part of the ignimbrite upto the zone of Later, they got an overwash of 50 to 100 
topsoil material from the upper parts which has
parts which has
Town rd 
;i> Just
e  a v i n p 1 ij <_• t- # 1 11 g. 
iJ l I Ve ly have
^ily)
,<>r
at
washes
weak I he
the
of
subangular blocky structure.
ext re in e foot of volcanic
This alluviaatlilon   uviofatiaonsh I middle Holocene period
young soils formed from this
south, across the river, the area an escarpment. This area had been ash deposited over the escarpment
of ash probably occurred mostly
Holocene period as is ev x dem ed f rom
alluviated ash which did 
s u  f f 1 c i e n t
required 1 ike
of
time (nor probably the for the formation c.
in older soils of the urea.
v the moisture rejjia. ‘"“J
of the E or a pronounced 
They do show some
rather
‘-lay in the subsoil but the B orlZ°*] ,,en,.rally 
These soils are -Iso •-'y dee,. .....1^J
* 20
oped . to
wh i eh
30 cm thick, dark coloured, gia>iu is underlain by a very ,u L
yis
h brown-72-
to angular blocky clay loan, or sil ly day loain b
, have no horizon. These soils have remained under ,,d  l(eI drainage conditions and show less mottling.
,*? noncalcareous and a zone of lime accumulation “ nrs below 150 cm depth.
<)C» u 1APPENDIX IV:
Soil types/
\ sub-types
Crops
<1% slope
“4-6% slope
1-2% slope
1 \
Al
2
A2
3
Bl
U
B2
5
Cl
6
C2
7
D
8
B3
9
E
10
Wheat
Barley
Maize
Sorghum
Tef
Oats
Rice
Fbtato
Tomato
Red pepper
Onion
Cabbage
Carrot
Peas
Harricot beans Phaseolus pulses
Chick peas
Lentil
Sunflower
Safflower
kapeseed
Mustard
Linseed
Soybean
Citrus
P-^_
Crapes
m *-.
Clive
Pomegranate
°ugarbee t
sugarcane
iODacco
^CLralfa
Pl /-s. .
clovers
S2d
S2d
S2d
S2d
SI
S2d
S3ci
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2rd
S2rd
S2d
S2d
S2d
S3dc S3rd
S3rd
S3rd
S3rd
S2r
S3dc
. S3dc S3d
S2d
S3rd S3rd S3rd S3rd
SI
S3rd S3ci S3 rd S3rd S3rd S3rd S3rd S3rd S3rd S3rd S3rd S3ra S3rd S3rd S3rd S3rd S3rd S3rd S3rd S3 rd S3 rd S3rd SSrd
S3r
S3rd S3rd S3 rd S3rd
SI
SI
SI
SI
SI
SI
S3ci
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
S2c S3dc
SI
S2d
S2d
SI
S2c
S2c
SI
SI
SI
SI
SI
SI
SI
SI
S3ci
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
S2c
S2c
SI
SI
SI
SI ■
S2c
S2c
SI
SI
SI
SI
SI
SI
SI
SI
S3ci
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
S2c S3de
SI
S2d
S2d
SI
S2c
S2c
SI
SI
S2r
S2r
S2r
S2r
SI
S2r
S3ci
S2r
S2r
S2r
S2r
S2r
S2r
S2r
S2r
S2r
S2r
S2r
S2r
S2r
S2r
S2r
S2r
S3rc S3rc
S2r
S2r
S2r
S2r
S3rc S3rc
S2r
S2r
S3e
S3e
S3e
S3e
S2e
S3e
N2
S3e
S3e
S3e
S3e
S3e
S3e
S3e
S3e
S3e
S3e
S3e
S3e
S3e
S3e
S3e
S3e
S3e
S3e
S2e
S3e
S3e
S3e
N1
S3e
S3e
S3e
S2e
S2e
S2e
S2e
SI
S2e
N1
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e S3ec S2ec
SI
S2e
S2e
S2e S3ec S2ec
SI
SI
S2d
S2d
S2d
S2d
SI
S2d
S3ci
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S3dc
S3dc
SI
S2d
S2d
S2e S3dc S3dc S2d
S2d
1-2% slope
“>6T"
slopt
2-3% slope
1
3
4
5
6
7
8
9
10
Wheat
uariey
l ^ize
^ ghum
iei
* uce
^tato
Or
S2de S2de S2de S2de
SI
S2de
Nl
S2de
S3rd S3rd S3rd S3rd
S2e
S3rd
Nl
S3rd
S2e
S2e
S2e
S2e
SI
S2e
Nl
S2e
S2e
S2e
S2e
S2e
SI
S2e
Nl
S2e
S2e
S2e
S2e
S2e
SI
S2e
Nl
S2e
S3re S3re S3re S3re
S2e
S3re
Nl
S3re
Nl
Nl
Nl
Nl
Nl
Nl
N2
Nl
S2e
S2e
S2e
S2e
SI
S2e
S2e
S2e
S2ed S2ed S2ed S2ed
SI
S2ed S2ed S2ed-74-
1
2
3
4
5
6
7
8
9
10
Tomato
ped pepper
Onion
Cabbage
Carrot
Peas
Haricot beans Phaseolus pulses Chickpeas
Lentil
Sunflower
Safflower
Rapeseed
Mustard
Linseed
Soybean
Citrus
Grapes
Olive
Pomegranate
Sugarbeet
Sugarcane
Tobacco
Alfalfa
Clovers
S2de
S2de
S2de
S2de
S2de
S2de
S2de
S2de
S2de
S2de
S2de
S2de
S2de
S2de
S2de
S3dc
S3rd
S3rd
S3rd
S3rd
S2re
S3dc
S3de
S3d
S2d
S3rd S3 rd S3 rd S3 rd S3rd S3rd S3rd S3rd S3rd S3rd S3rd S3rd S3 rd S3rd S3rd S3rd S3 rd S3 rd S3rd S3rd
S3r
S3rd S3rd S3rd S3rd
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e S3ec S3dc
SI
S2d
S2d
S2e S3ec S3ec
SI
SI
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e S3ec S3ec
SI
S2e
S2e
S2e S3ec S3ec
SI
SI
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e S3ec S3dc
SI
S2d
S2d
S2e S3ec S3ec
SI
SI
S3re S3re S3re S3re S3re S3re S3re S3re S3re S3re S3 re S3re S3re S3 re S3 re S3re S3rc
S2r
S2r
S2r
S2r S3 re S3re
S2r
S2r
N1
N1
N1
Nl
Nl
Nl
Nl
Nl
Nl
Nl
Nl
Nl
Nl
Nl
Ml
Nl
Nl
Nl
Nl
Nl
Nl
Nl
Nl
Nl
Nl
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e S3ec S2ec
SI
S2e
S2e
S2e S3ec S2ec
SI
SI
S2ed S2ed S2ed S2ed S2ed S2ed S2ed S2ed S2ed S2ed S2ed S2ed S3ec S3cd
SI
S2ed S2ed S2ed
S3cd
S3cd
S2d
S2d
1
2
3
<1% si
4
ope
5
6
7
4-6%
slop
8 ‘
> 1-2%
9
slope
10
Wheat
Parley
Maize
Sor ghum
Ter
Oats
Rice
Potato
Donato
P^d pepper
Onion
Cabbage
Carrot
Peas
£*ieot beans Aeolus pulses
S2d
S2d
S2d
S2d
SI
S2d
S3ci
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
SI
S2d
S3ci
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
SI
SI
SI
SI
SI
SI
S3ci
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
S3ci
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
S3ci
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
S3ci
SI
SI
SI
SI
SI
SI
SI
SI
SI
S3e
S3e
S3e
S3e
S2e
S3e
N2
S3e
S3e
S3e
S3e
S3e
S3e
S3e
S3e
S3e
SI
SI
SI
SI
SI
SI
Nl
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
S3ci
SI
SI
SI
SI
SI
SI
SI
SI
SI-75-
1
2
3
k
5
6
7
8
9
10
Chickpeas
Lentil
Sunflower
Safflower
Rapeseed
Mustard
Linseed
Soybean
Citrus
Grapes
Olive
Pomegranate
Sugarbeet
Sugarcane
Tobacco
Alfalfa
Clovers
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S3dc
S3dc
S2d
S3d
S3d
S2d
S3dc
S3dc
S3d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S3dc
S3dc
S2d
S3d
S3d
S2d
S3dc
S3d
S3d
S2d
SI
SI
SI
SI
SI
SI
SI
S2c S2dc
SI
S2d
S2d
SI
S2c
S2c
SI
SI
SI
SI
SI
SI
SI
SI
SI
S2c
S2c
SI
SI
SI
SI
S2c
S2c
SI
SI
SI
SI
SI
SI
SI
SI
SI
S2c
S2c
SI
S2d
S2d
SI
S2c
S2c
SI
SI
SI
SI
SI
SI
SI
SI
SI
S2c
S2c
SI
SI
SI
SI
S2c
S2c
SI
SI
S3e
S3e
S3e
S3e
S3e
S3e
S3e
S3e
S3e
S2e
S3e
S3e
S3e
N1
S3e
S3e
S3e
SI
SI
SI
SI
SI
SI
SI
S2c
S2c
SI
SI
SI
SI
S2c
S2c
SI
SI
SI
SI
SI
SI
SI
SI
SI
S2c
S3cd
SI
S2a
S2d
SI
S2c
S2c
SI
SI
1-2% slope
>6%
slope
2-3% slope
1
2
3
U
5
6
7
8
9
10
Wheat
Barley
Maize
Sorghum
Tef
Oars
Rice
Potato
Tomato
Keu pepper
Onion
Cabbage
Carrot
Peas
tricot beans
f^seolus beans Chickpeas
Lentil
Sunflower
Lafflower
^upeseed 
^stard
Linseed
Soybean
Citrus
Olive
S2d
S2d
S2d
S2d
SI
S2d
S3ci
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S2d
S3dc
S3dc S2d
S3d
S3de S3de S3de S3de S2e S3de
S3ci S3de S3de S3de S3de S3de S3de S3de S3de S3de S3de S3de S3de S3de S3de S3de S3de S3dc S3dc S3de S3de
SI
SI
SI
SI
SI
SI
S3ci
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
S2c S2dc
SI
S2d
SI
SI
SI
SI
SI
SI
S3ci
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
S2c
S2c
SI
SI
SI
SI
SI
SI
21
SI
S3ci
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
SI
S2c S2dc
SI
S2d
S2e
S2e
S2e
S2e
SI
S2e S3ci
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e S3ec S3ec
SI
S2e
N1
N1
N1
N1
N1
N1
N2
N1
N1
N1
N1
N1
N1
N1
N1
N1
Ml
N1
N1
N1
N1
N1
Ml
N1
N1
Ml
N1
S2e
S2e
S2e
S2e
SI
S2e
N1
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e S3ec S2ec
SI
S2e
S2e
S2e
S2e
S2e
SI
S2e
S3ci
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S2e
S3ec S3cd
SI
S2ed-76-
1
2
3
u
5
6
7
8
9
10
pomegranate
Sugarbeet
Sugarcane
Tobacco
Alfalfa
Clovers
S3d
S2d
S3 de S3dc
S3d
S2d
S3de S3 de S3de S3 de S3d
S3d
S2d
SI
S2c
S2c
SI
SI
SI
SI
S2c
S2c
SI
SI
S2d
SI
S2c
S2c
SI
SI
S2e
S2e S3ec S3ec
SI
SI
Ml
N1
Ml
ill
N1
Ml
S2e
S2e
S3ec
S3ec
S2e
S2e
S3ed
S2e
S3cd S3cd S3ed
S2e
--------------- --77-
( j. ,(?k IFT ION 01' TYPICAL SOILS PROHLlS AND y)', ANALYTICAL DATA
I'i k> i i ] -• •lcbri ipl 1 ons
SOIL TYPE AJ MOLJ.IC PLANOSOLS
Parent i“-«1
Phys tog rap 
[■ |. Vai i : (' 1 l ill-1t 1 •
a
l er t u I
i a 1 c haracter isj .
Old volcanic ash.
Level to very gently sloping plains; 0 2“. slop.-
1«IO IK25 in
A n n u a 1 i ai n 1 a 11 about < 50 iniu , mainly during Jun
i a
Drainage'
Surface s
September;
I hroughou(
I uiper lect 1 y al ini Iy:           Nil
F v idem <• of erosion:
Vegetation land use:
‘•"^’■lun: About GO m BM2 and 900 lie ar Kos he «°02’N and
mean daily temperatures 17.7 21" r year; no frost.
drained; groundwater 20 ui deep.
None observable
Mainly dry-farmed to maize, sorghum, red pepper and lef; partly open grassland uith 60 80’i ground cover; few trees of Acacia and Ficus species.
northeast (magnetic bearing 40°) from m northwest of the Woja River bridge
village on Zwai Butajira road; approx 38°3l’E tubs. site But/10, on open
grassland with about IS slope). -l-sc rpt ion:
A, “ 0 15 e
m
v,? ‘v dark grey  10YH3/l) moist and greyish brown 
k
0YR5/2 dry; 1 o a in; weak medium granular; slightly ’ ,l<k ^ slightly plastic, friable moist, slighllv hard 
y
’ ly’ (omiuon fine tubular' and medium vesicular pores. 
°n< al cur<?o s; many fine and medium routs; clear smooth 
U
J undary; pH 7,2 (sample No. But/10 1)
'**        31
< in
iV',y Jurl< greyish brown (10YR3/2) moist and grey.a. 
, ',w “         U0YR5/2) dry; loam; moderate medium and fun-
Ir ‘“,'ul'*1 blocky; slightly  sticky.  slirJilH pl.i-ii'. 
l. 1H Jbl,“
slightly hard dry; common tine lubu a
. j S ’ ,lGnca I enreous ; common fin** and very ‘ u s,““olh boundary; pl! 7.0 (sample No. But 10 - •-78-
iO   ‘
r:
u‘
blown 10YR5/2) moist and light grt-y 10YK7 (i
IlO t
.1, ,          sj.ll !.!?»■ that -_gi*P.ro aches _ sil t structureless
i :      t      i<kv.      nonplast      i      <•,      very      friable      moist,      soft      dry: few      fine      tubular      pores:      very      few      small      ,1-3      mm      ,      soft ><•      Mo      nodules;      iionra      I      careous      few      fine      and      very      fine roots:         abrupt         smooth         bouinlaiy;         pH         7.3         (sample         N,.,. Hut I 3           .
•) IH
-10 /4 3-65 Vei  y an d
1) r own
« 111 du r k 
f i n c mo t
greyish brown (10YH3/2; moist, 
comuioB medium
faint
to distinct yellowish brown and strong 
I
les; si1ly_________            silty_____crI1 a ay;y; m mode oderraattee coarse prismatic,
break i uy. 
t o      medium angular blocky;
very fares
pores non Cd
f i l ill < or
moist, probably
very hard dry; cutans ' 
sticky, few indistinct
few verv fine
I eiv
sma 1 1 
I < ar eous; smooth boundary;
f ew pH 7.5
( 1 3 min) f l ne and 
(samp 1e
soft Fe Mn 
y fine roots;
But/10 1 .
p 1 a s t i < , pressui • 
tubular nodules. 
gradual
•> Big I Hr, 108 < M|
D a r k       >» r e y i s h 7.5 Y ft 5 6i moi
1 ine dist met
li rown s t ,    b rown
lOyibl
>
ver No.
■ n
and strung brown
to dark brown when rubbed, mans
t o
silty blocky; modern t common 
b e Mn h a rd , ni/ih u 1 f i lie
clay loam;
st icky, < 1y thick,
fi ne t ub u1 nodu Les;
proni   inenl   , moderate
black (10YK2/1 mottles fine and medium angular
p 1 a s t i c,
friable moist, hard dry 
broken       clay       cutans       on 
both ped faces
ar very
pores;
few ,
s ubangu1 ar ca1clte
carcous, calcareous
roots* gradual smooth boundary’
few, small (2'5 mm/, hard small to large (3-20 mm . 
nodu 1 es/went her rd I ragmen t s in pockets; very few very 
pH 7.6 (Sample No
But
lO --79-
O I OK I 50 < HI
Strong 
b/own 
(/.5YR5/6)
and 
dark 
greyish 
brown 
(10YR4/2)
moist, 
dark 
yellowish 
brown 
(10YR4/4)
when 
rubbed,  many  medium distinct very  dark  grey  (10YR3/1)
mottles; c l.ay----------------------- 1  9_a w ±.  strong  fine angular blocky;
slightly  sticky,  slightly  plastic,  friable moist,  hard 
dry; moderately  thick,  broken  clay  cutans on  both  ped 
faces; common  fine tubular pores; few,  small (2-5  mm), 
bard  Fe-Mn  nodules; very  few small to  large (5-20  mm), 
hard            subangular
to            spherical
calcite            nodules/weathered 
fragments; nonca 1  careous,  calcareous in  pockets; concentration  of powdery  lime in  a few pockets; very few,  very  fine roots; gradual smooth  boundary; pH 8.0 (sample No. But/10 6).
150166 cm 2 Btxk
S ti ong moist, mottles; oxlde, <
t ub u1 ar subangular, 
brown       (7.5YR5/6)       and       dark       reddish       brown       (5YR3/4 common medium distinct very dark greyish brown
1 oam; massive; weak fragipan, clods slake in water;
pores; frequent, small
cemented by iron
very to 
few, 1 arge
very
hard,
weathered
very fine (5 50 mm,, 
calcite
fragments/nodules;
pockets; mmany  any lime
lime; no No. But/10
2UC 166 220 cm
roots; clear smooth boundary; -7) .
noncalcareous, calcareous in inycelia and few pockets of powdery 
pH 8.2 (sump]e
Brown  to  dark  brown  (7.5YR4/4) moist when  rubbed; low «■ th  a y  approaches silt loam: few,  small (310  mm,  soft 1  i me nodules; slightly  calcareous,  calcareous in 
pockets; pH 7.5 (sample No. But/10-8).
2Ck -20-235 ciu
Yellowish       brown       (10YR5/4)       moist       when       rubbed;       silt       l_u       am th at        ajp roaches very fine sandy loam; frequent, snia 11
to  large, hard lime nodules; strongly calcareous; abundant soft powdery lime; cemented by lime below -3a
m depth.
^^“arks •
i ) ‘ J )
The occurrence of fragipan at 150 cm depth as found in this profile is uncommon.
The description of the profile below 160 cm depth is based on auger sample^ augering could not be done beyond - due              to occurrence of 3
lime-cemented pan below.-80-
s0 1 L TYPE_ A- ~ EUTRIC PLANOSOLS Gene ral j:haracteris t ics
Parent material: Old volcanic ash Fhysi o ;r.<phy: Level to very penliv .i
"'-■'•non' 
f
f, L Climate:
1810 to 1825 m
V Io{'ln8 plains; 0 2’. slope
Annual rainfall about 750 mm, mainly during June to 
September;
mean          daily            temperatures
throughout the year; no frost.
Imperfectly drained; groundwater > *>0 iu deen 
salinity:
Nil
17.5       -      21°C ’ ’
Evidence
of
erosion;
Vegetat ion/1 and use:
None observable
Mainly dry-farmed to maize, sorghum, red
pepper and tef; partly open grassland with 50-60". ground cover; few Acacia and
Ficus t rees.
b) Typical profile
1 u ra t ion:                   About 7 km nort h-nor t heas I of the Woja Haver bridge near Koshe village along Zwa1-Butajira road; approx. 8°05’N and 38°32’E (obs. site But/89 , 
on open grassland with about 0.5% slope;. Profile           descri p11 on:
Ah 0-ld
cm
Very dark (10YR4/2) siightly slightly hard interstitial fine roots; But/89-1).
brown       (10YR2/2)       moist       and dry;          lloaoamm;;         weak          medium
dark  greyish  brown 
granular to crumb;
s t i cky,
dry; pores;
clear
siightly plastic, common fine and noncalcareous;
smooth boundary;
friable moist, medium tubular and
many 
fine     and 
very 
pH 6.4
(sample No.
E  18-33
c in Brownish (10YR7/1 ) nonplastic, a pan when line tubular nodules, roots;
But/89-2
grey dry; very 
(10YR5/1.5) moist
and mass i ve;
light grey 
______________                       silt loam;              nonst icky , 
dry)    * pores;
friable moist, hard dry (behaves like many very fine interstitial and few
few small
abrupt ) .
noncalcareous;* smooth boundary;
common
(3-10  mm) ,  soft Fe Mn fine and  very  fine pH 6.6 (sample No.
211 N 35
c m
Ve »y            dark ‘^roaches
s 'icky,
plastic, firm
greyish brown (10YR3/2) moist; clay that siin_ clay; strong medium angular blocky:
moist, very hard dry; thick-81-
continuous clay/oiganir matter cutans on  Lott,  p.-d faces; common  very  fine tubular pores; very  few small ,2-3  mm;,  soft FeMn  nodules,  nonca 1  careous; cumin;.i. fine and  very  fine roots; gradual smooth  boundary; pH G.b (sample No. But/89-3).
2Bt2 61       90 < mi
Dark  brown  (10YR3/3) moist; clay  1  oam; moderate medium angular blocky; sticky,  plastic,  friable moist,  hard dry; moderately  thick,  broken  clay  cutans on  both  ped faces and  in  pores: many  fine and  very  fine tubular pores; noncal careous; few very  fine roots; diffuse- smooth boundary; pH 6.6 (sample No. Rut/89-4).
L'Btg 90      155 c in •
Dark             yellowish             brown 
common fine faint to
(10YR4/4) moist when rubbed,
distinct strong brown and black
mottles;
clay 
loam;
strong 
fine
angular
blocky;
slightly 
sticky, 
slightly 
plastic, 
friable
moist, 
haid 
Remarks:
dry; moderately  thick  broken  clay  cutans on  both  ped faces and  in  pores; many  very  fine and  fine tubular pores; slightly calcareous; few very fine roots; pH 6.6
(sample No. But/89-5).
The profile has somewhat lower pH in  the subsoil below 61  cm than  what is most commonly  observed  (7.0  to  8.0) foi these soils.
3.
SOU TYPE Bl - GLEYIC PHAEOZEMS
a)          General char ;ic t er is ti cs
rial:            Old volcanic ash
Y-      Level      to      very      gently      sloping      plains,      0      _•      s      ope. 1808 to 1825 in
Annual rainfall about 750 mm, mainly durin» September; mean daily temperatures throughout the year; no frost
Moderately well to imperfectly drained.
e                      ^-0 in deep.
e 3  o 1 i n i t
y :                    N i 1
*/
er osion:
None observable
4     1 *■">/ 1 an.j use :
Mainly 
pepper,
dry-farmed to maize, tef
grassland with
groundwater
, sorghum, red uud pulses; partly open
60-80* ground cover few-82-
Acacia and Ficus trees.
b ' T>.P i ca .L -Profi J_e
LucaCion:
About 3.4  km north*northwest of the Wojj River bridge near Koshe village along  Zwai-Butaj n  a road, approx.  8°03’N and  38U31’E  tobs.  site But/126, in  a cultivated  field  with  stubbles of lentil crop with about 0.52 slope).
profile description:
Ap 0 20 cm
Very dark (10YR5/1.5) crumb; moist , tubular
(10YR3/1) moist and loam; moderate medium
sticky, slightly plastic,
brownish grey granular to 
f rlab 1 e
roots; Beil 126
grey dry;
slightly
slightly hard dry;
pores; c 1 e a r
1).
few fine and common very noncalcareous; many fine and very 
smooth boundary; pH 7.2 (sample
fine fine
No.
AB 20 37 cm
Very  dark  grey  (10YR3/1) moist and  brownish  grey 
(10YR5/1.5) dry; clayloam: weak  coarse prismatic, 
breaking 
to 
moderate
medium
angular
blocky;
slightly 
sticky, 
slightly 
plastic, 
friable
moist, 
hard 
dry 
few
fine to  medium and  common  very  fine tubular pores; nonca1careous; common  fine and  very  fine roots; gradual smooth boundary; pH 7.2 (sample No. Dut/126-2).
Bt u 37-78 cm
Very brow n 
dar y 
greyish         brown         (10YR3/2)        moist        and        greyish 
strong break i n g I* 1 as tic, cutans tubular nodules;
(10YR5/2) brown 
to firm
on both pores;
f ew
dry, mottles; moderate
moist , ped 
very large
common      fine      and      medium,      distinct clay loam; weak medium prismatic
fine very
faces;
few,
(10 20
Linoik               a--1c--a--r-e-ous ---, ;       -f e---w-  very oundary; pH 7.2 (sample No. But/126-3).
HI p o 7 o
7R  ios/lio cm
Uurk brown (10YR3/3) moist, Prominent strong brown and 
i  —loftJPL moderate medium
\ • C * Plastic, friable
llc k, broken, clay cutans
angular blocky; sticky, hard dry; thin patchy clay 
common fine and very fine small (23 mm) soft Fe Mn 
mm), rotten snail shells, fine roots; gradual smooth
many medium distinct to dark grey mottles; s l 11 y 
and fine angular blocky; moist, hard dry; moderately 
on both ped faces and inpores; few, light very
-83-
few fine and many verj fine tubular pores small (2-5 iuiu) , soft Fe Mn nodules; few puck.is
brown rock powder tnot lime); noncal careous; fine roots; few large (10 20 mm/,
Btg'd Hl 2
shells; few tongues of Btgl horizon base ol this horizon; gradual wavy (sample No. B u t/12 6 1
110     145/148 cm
ve r > of
few
ro t ten snaj 1
extending       tn       the boundary; pH 6.7
Il row Ji to ( 10YR5/6) dark grey moderat e si lght1y 
dai k brown (7.5YR4/2) and
ydluwtsli brown
moist, many medium distinct to prominent very 
mot t les; 1 oam that___________ approaches_____ c I ay_ l.Qam ;
thick, and mm ) , routs ;
medium subangular
plastic, friable
broken, clay cutans on both ped face
common very fine tubular hard Fe-Mn nodules:
diffuse smooth to
No. But/126 5) .
Bfg 115
148 220 L i ghl
cm
b rown         \7.5YR6/4)
7.5YR4/2 ) very dark subangu1 ar f rlab 1 e
t ubu1 ar nodules;
mo      ist,      common grey mottles;
blocky; slightly 
mu ist,
pores;
hard dry;
very few,
noncalcareous ,
blocky slightly sticky, moist, hard dry; moderately 
; few fine pores; few, small (3 5 
nonca1careous; few very fine wavy boundary; pH 6.6 \sample
and brown to dark brown med mm distinct to prominent
l.oaiu^ weak medium and coarse sticky, slightly plastic,
few fine and common very fine small i2~5 mm), hard Fe-Mn 
calcareous in pockets; no
roots;
2 2 5 c m Brown common
pH 7.0 (sample No. But/126-6).
2mk 220
r
7.5YH5/4) and greyish
coarse distinct olive green mottles;
brown i 2.5 Y W 5 / 2 ) moist, 
t ha t a_pp roaches very fine sandy J_oam_l cemented; strongly calcareous with
massive;
abundan t
silt 1oam
sIrongly powdery
f<( nir»rks :
The description  below 160  cm is based  on auger samples; augering  was not possible beyond  225  cm due to  strong  cementation with lime below that depth.4.
SOIL TYPE ^2 LIJVIC PRAJOZEMS !) General characteristics
parent material: Old volcanic ash
Physiography:                 Level t
Elevation:                18081825 m Climate: Annual rainfall about 7Rn
September; mean doily
to very gently slopnig pJdlns; Q.
nun, mainly during June to temperatures 17.5 21 C
C
throughout year; no frost Drainage:             Moderately well drain*/ Surface salinity: Nil
* groundwater >20
ni deep
Evidence of erosion:
Vegeta t i on,/land use:
None observable
Mainly pepper, grassland
dry-farmed to maize, 
tef and pulses;
Acacia and
with 60 BOX ground Ficus trees.
sorghum, red part Jy open 
cover; few
Loca tion :
Ty pic a 1_ profile
About      1.3      km      north      of      the      Woja      River      bridge      near
Koshe           village           along           Zwai-Butajlra           road;           approx. 
8°02’N         and         38°31’E         (obs.         site         But/121,         in         a
cultivated 
field 
with 
stubbles
of
sorghu
m
crop, 
about IX sl
ope).
Profile description:
A P 0 16 cm
Very 
dark 
greyish 
brown 
(10YR
2.6/2)
moist
and 
dark 
Ah
greyish  brown  (10YR4/2) dry; 1  oaiu; moderate fine granular to  crumb,  slightly  sticky,  slightly  plastic, very  friable moist,  slightly  hard  dry; many  fine and medium tubular pores; noncalcareous; many  fine and medium roots; clear smooth  boundary; pH 6.5  isample No. B ^t/121-l) .
1C-53/63 cm
Very brown blocky; moist, pores;
cle a r
H u t / 121
dark greyish brown (10YR3/2) (10YR4.5/2) dry; loam; weak 
slightly sticky, slightly hard dry; noncalcareous; common irregular boundary;
-2) .
moist and greyish coarse subangular
slightly plastic, very friable
many 1 . fine
PH
< E)
£3/63-63 cm Dark d r y;
Erey            (10YR4/1.5)            moist 1 <•> a in ; moderate medium
fine and medium tubulai and very fin<- roots:
6.6 (sample Xu.
a1 l nd l ghtight  gr gr ey (ey  10Y(lURYK6 1u i angular blocky; slightly•J u
s t i c k y » slightly plastic, friable moist, fine and medium tubular pores; very mm ) , soil 1 e Mn nodules; noncalcar ecus; very fine roots; abrupt broken boundary; No.     But/121-3).
hard dry many few, swal 1 i 1 5 
common fine and pH 6.8 k sample
Very  dark  greyish  brown  (10YR3/2) moist; tlay  loam;
moderate to  strong  medium angular blocky: slightly 
sticky, 
slightly 
plastic, 
friable
moist, 
hard 
dry;
moderately 
thick, 
broken, 
clay/organic
matter
cutans
on 
both       ped       faces;       many       fine       and       very       fine       tubular       pores; very        few,        small       (1—5        mm),        soft        lime        nodules;       slightly calcareous;        few        very        fine        roots;        clear        smooth        boundary pH 7.0 (sample No. But/121-4).
Bt2    103 137 cm
Dark  yellowish  brown  (10YR3/4/ moist; clay  loam; strong medium angular blocky; sticky,  plastic,  firm moist, very  hard  dry; moderately  thick,  continuous clay  cutans on  both  ped  faces and  in  pores; many  very  fine tubular pores; few small to  large (5  20  nuiij,  hard  lime nodules; calcareous; few very  fine roots; clear smooth  boundary; pH 7.6 (sample No. But/121-5).
B13 13 7- 200 cm t-
Dark yellowish brown (10YR4/6) moist; loam; moderate fine angular blocky; slightly sticky, slightly plastic, friable moist, hard dry; moderately thick, broken, clay cutans on ped faces and in pores; many fine and ver> fine tubular pores; calcareous; no roots; pH 8.0.
Remarks:
i • i i )
The E horizon is absent in most soils of this type; it is discontinuous in tins profile too.
The           profile
is           unmottled           throughout, 
whereas         the         soil         is         normally         luotil.-J below about 100 cm depth.soi~ haplic phaeqzems
a)
Ge_nera.l characterist i cs
Pare
_..nt material:                     Redeposited (alluviated) volcanic ash
i u»
.         /-»             *    ■»
—   — ■ — 
Gently sloping plain at
escarpment; 1-3* slope
1
-1
physiography•
g I e v a tion :      1808 1812 m
C 1 i mate:
Annual rainfall about 750 
September;
mean daily
throughout year; no frost
Well to moderately well drained 
the fool of an
mm,
temperat ures
mainly during June to 17.5-21°C
Drainage;
Sur face sali n i I y :
Evidence of erosion:
Vegetal i on/1 and use:
Nil
None observable
Dry-farmed  to  niainly  maize,  sorghum,  tcf and  red  pepper; few trees and  bushes of mainly Acacia species.
b ; Typical p r o fi1e
I.oca I ion:                About      500      ni      south      of      the      Woja      Diver      bridge      near Koshe           village           along           Zwai-Butajira           road;           approx. 8°       01       ’       N       and       38U31’E       (ubs.       site       But/88,       in       a cultivated field with stubbles of beans crop; about
1 * slope}
Profile description:
A P 0-17 cm
Very  dark  brown  (10YR2/2) moist and  dark  greyish  brown ( 10YR4/2) dry; 1  o  am; weak  medium granular to  crumb, slightly  sticky,  Tlightly  plastic,  very  friable moist, slightly  hard  dry; many  fine and  medium tubular pores, nonca 1  careous; many  fine and  very  fine roots,  clear smooth boundary; pH 7.6 (sample No. But/88-1).
AB  Bw
17      71 cm
x
... 
lualIK moderate
medium
Very d
ark grey 
subang
friable
ular
 moist, slig
blocky;
htly hard 
slightly 
B °1   tic 1Q
ky slightly plas
dry
’many 
-3
tic,
f^ne
and J'crY
(20
0 mm! , black
fine
tubular
pores;
very 
eW ’
o car
i   eous;
common 
vcr>
pieces of artefacts/gravel; no"
fine roots; gradual smooth boundary. P but/88 2 ) .
71
1 C Hl
Very
1,1  «‘d 1 uUl
dci rk
grey
b I icky
prismatic,
> plastic,
H  7.4 (sample No.
(10YR3/1) moist; clay loam, moderate breaking to fine angular block)
firm moist, hard dry;moderately thick,patchy. 
clay/organi
c
matter
cutans
OI1
ped 
faces. 
very 
fine
tubular
por
es;      very 
few, 
large
20 
i0      mm
, 
BJIll
. 
fc>la<-k
pieces
o
f
artefact
s/
gravel;
non
calcareous;
few
very       fine       loots;       clear       smooth       boundary;       pH       7.3       sample No. But/88-3).
Very  'lark  brown  (10YR2/2) and  yellowish  brown  (10YR5,4; moist.  ‘lark  yellowish  brown  (10YR4/4) moist when i ubbed; clay  loam; moderate fine subangular blocky, sticky,  plastic,  friable moist,  hard  dry; moderately thick,  broken,  clay  cutans on  both  ped  faces and pores; many  fine and  very  fine tubular pores; few, small to  large (5-50  mm),  hard  lime nodules slightly calcareous; few very  fine routs; gradual smooth boundary; pH 7.0 (sample No. But/88 4).
BCb 110        152 cm +
Light yellowish brown ( 1 0 Y R 3 / 2 )
b rown
moist,
10YR6/4)     and     very     dark     greyish dark yellowish brown (10YR4.4
kcmuiks•
C
moist when  rubbed; 1  oam; weak  medium angular blocky; slightly  sticky,  slightly  plastic,  friable moist,  hard dry; thin  patchy  clay  cutans on  ped  faces and  in  pores, few,  small to  large (5  50  mm),  hard  linn- nodules, slightly calcareous; pH 7.4 (sample No. But/88 5).
The      two      different      colours      in      the      last      2 
horizons       are       probably       due       to       the       past g ley mg process.
1 k_TYPE C 1 - GLEYIC LUVISOLS
‘        «i*.i h \ r_n_l charact er i s I i cs I'hvv U “‘nteriui; Old volcanic ash 
LI ev 
UCnuui | .
e
’ bevel to very gently sloping plains, 1808 1825 m
Annua] rainfall about 750 September; mean daily 
n o. i r mm. mainly during June to 
temperatures
17. •
throughout the year; no frost. Moderately well to i .
- 0 ni d e e p
imperfectly drained; groundwater
r.
1.       1
 •  < e
J
v
 . 1
Vlll>‘nce : plni,y-
Nil
egr 'Ul , f eros‘on: ll °'Vlund use:
None observable Mainly pepperwith        50-60%        ground        cover Acacia and Ficus species.
few trees of
b ) local i<»» :
Typical profile
About 2.5 km northwest of near Koshe village along approx. 8°03’N and 38°3l’E on a cultivated field left harvest; about 0.5% slope).
the Woja River bridge Zwai-Butaji ( a road;
(obs. site Hut/127, fallow after maize
profile description.
Ap 0     18 cm
Very  dark  greyish  brown  (10YR3/2) moist and  greyish brown  (10YR5/2) dry; loam; weak  medium granular to 
cruiub;
slightly 
sticky, 
slightly 
plastic, 
friable
moist,  slightly  hard  dry; few medium,  common  f±ne and many  very  fine tubular pores; noncalcareous; common medium and  fine roots; clear smooth  boundary; pH 6.6 (sample No. But/127-1).
B t g1 18-56 cm
Very  dark  greyish  brown  (10YR3.4/2) moist and  greyish brown  (10YR5/2) dry,  common  medium faint to  distinct black  and  dark  brown  mottles; clay  loam that approaches £j_5yj.  moderate coarse prismatic,  breaking  to  medium angular blocky; sticky,  plastic,  firm moist,  very  hard 
dry;             few             pressure
faces/indistinct
slickensides;             few
«tg2
fine and  common  very  fine tubular pores; noncalcareous; few fine and  very  fine roots; gradual smooth  boundary, PH 6.8 (sample No. But/127-2).
56-81 cm
Dark brown Li ack and moderate p1 us t i c, c u t a n s
(7.5YH3/2) moist, reddish brown “ottleS’
medium and fine friable moist, hard
r
on both
ped faces and in pores:
common medium distinct silty clay loam
blocky; s t icky, thin broken clay 
* *; few indistinct
slickensides; few pores; very few, noncalcareous;
few
fine swal 1 
very
—t/iQ7 
and common very fine tubular (1-3 mm), soft Fe-Mn nodules; fine roots; diffuse smooth
Boundary; pH 7.0 (sample No. Bu / 81 -18O ciu
H r own moist,
6rUUn subangul ar
to dark yellowish brown 
-----------  to prominent black, rust many medium distinct t
3)-
a , 10YR4/4 and 10YK-1/J
and
yellowish       brown       mottles.       Ijtami       moderate       fine blocky, slightly sticky, slightly plastic,very thick, pores, 
s ni a 1 i (5-20 calcareous
f riublc btoken, common 
moist, slightly
clay cut an s on 
fine and very fine tubular pores;
(2 4 mru) , hard Fe-Mn nodules; mm) >
hard dry, moderately both ped faces and Ai>
feu , f ew, smal 1 to large
soft lime nodules; slightly calcareous, in pockets; no roots, gradual smooth
Cork
boundary; pH 7.2 (sample No. But/127-4).
i o 0 -19 5 cm*
1                 Vurieifutcd           colours,           yellowish           brown           (10YR5/4)           moist when         rubbed,         common         medium         faint         to         distinct         olive
brown            and            dark            grey            mottles;
fine            sandyloaa;
nonsticky,  nonplastic,  very  friable moist,  soft dry; strongly  cemented  below 195  cm depth; freqquent,  smalt to  large (5-20  mm),  hard  lime nodules; strongly calcareous; pH 8.0.
Rem a rks :                                               The description for the profile Leluw 175 cm is based on auger samples; augering was not possible beyond 195 cm due to the presence of a lime-cemented pan.
SOI L TYPE C2 - ALBIC LUVISOLS a) Gmieral characteristics
Parent material:
Phys iography:
Old volcanic ash 
Level to very gently sloping plains,
E lev, ti
a   on:
 1808-1825 m
r( .
Climate:            Annual            rainfall            about            J
0 -2*. slope
mm, mainly during June to
temperatures
17.5 21 C          11 7 G ' • J 1  -   1 - (
Q
September;
mean 
y
1 b  i «Ki g e:
throughout the y*ar« /“groundwater
Moderately well drained, gro
Vep,., 7 ot erosion: K  ^'tion/land use:
N'H
None observable
Mainly dry-farmed to maize, s~. ---------------------------
20  m deep sorghum, tef
and        red        pepper,        partly        open 
o
with      50      -602      ground      cover;      f- Acacia and Ficus species.
grassland few trees of
♦-“-«=      of
L !•<>( it 1
 ion 
Typical   profile
:                        About
7 km north-northeast of
r the woja River bridgenear approx. on open
Koshe village along a°05’N and 38°32’E 
grassland; about 0.5*
road
But MO ,
prof i *
des< iiption:
Very  dark  greyish  brown  (10YR3.4/2J moist and  light
brownish  grey  ( 10YR6  —) dry; 1  o  aru; massive to  weak 
medium
granular;
slightly sticky, slightly
plastic,  friable moist,  slightly  hard  dry; common  f 1  n  r* and  many  very  fine tubular pores; noncalcareous; many fine and medium roots; abrupt smooth boundary; pH 6.0.
E 13 35 cm
Light brownish grey (10YR6/2) moist and light grey 
I 0 Y R 7 / 1 j dry; s i It loam that approaches silt structureless; nons I icky, nonplastic , very Triable
moist, soft dry; few fine and common very fine tubular pores; noncal careous; few medium and common fine roots; abrupt smooth boundary; pH 6.0.
Bt 35 55           » m
Dark  brown  (10YR3/3) moist; clay  loam; moderate medium angular blocky; sticky,  plastic,  firm moist,  very  hard dry; thin  patchy  clay  cutans on  ped  faces; few line and common  very  fine tubular pores; noucalcareous; few fine
■ md very fine roots; gradual boundary; pH 6.5
Bl t 55-80 cm
Dark 
d i s t l n c t
greyish brown ( 10YR4/2]
moist; common medium
yellowish brown mottles;
plastic, 
G. 5
friable moist, hard
clay loam st icky, dry; noncalcareuus; pH
11 1 gb t
H 0-l30 cm Drown to 1  ° distinct
dark brown <%10YR4/3)
moist,     many     medium     faint
yellowish brown slightly plastic, 1--
mottles; loam; slightly
s  t i c k y , 
friable moist, slightly hard
dry ;
non
calcareous; pli 7.5.
B  t it b 2
130  175 <•„, Variegated 
"•oisl when “range and slightly
colours, rubbed, dark 
plastic,
dark many 
yellowish medium
Ul y ;
grey very pH 7.5.
mottles; friable
brown (10YR4 4) to coarse, distinct, 
1 oam; sliglitly sticky, moist, slightly hard
noncalcareous;
“ C" 175.
I' 0 e m Di own 
nt , ‘
T
to dark brown (7.5YR4/2? yellowish brown mottles. 
molsl, few mediurn. loam. slightly
cous;
pH 8.0.ill a i I' -"
The profile v upto 50 cm and not sampled for
was studied fr
from
lab.
uui  j   small  p  it
auger    samples    below, analysis.
SOIL T YPE_ D  CALCIC CHERNOZEMS
.1 ‘‘Ciirral cliaraet rrist ics
Patent material: Old volcanic ash
Physiography: Moderately steep to undulating
and gullied
E1«• v a t ton; Cl iiiml •• •
margins of plains; 4-16*. slope
1808 1815 m
Annual rainfall about 750 mm, mainly during June to
Drainage:
‘’ur face s
September;           mean           daily           temperatures           17.5           -2           PC throughout the year; no frost.
Well drained; groundwater > 10 in deep, 
Nil
Evldeni e
salinity:
of er os i on :
V • ge I o L l on land
Common rills and few gullies
use:
Mainly cover; belonging partly
grass 1 and some trees
to Acacia
dry-farmed to
with 60 7 0 *« ground and bushes, iuainl>
and Ficus species: maize, sorghum, tef
and     red pepper.
Typical profile
About 7.5 km north northeast fr Li idge close to the rivet bat , locate.! along Zwai
an.l 38°33’E (obs. site But. 4-t. with about 6« slope).
^•script ion :
• ill
x  fluoS’N
a  ' 
3 crasslauJ
ah o
° r y        i. | <lOYrN';‘'J' /rey <r umb- ~
Soft ’
n °dcal '• 
(10YR3/1) moist and dark greyish brown
1oam; moderate fine gianular I t i cky, slightly plastic, very friable moist,
medium and coninioii fine tubular pores
sandy iuuw,
s,,| oot        h        'Ue°us,        many        fine        and        medium        rents,        gradual boundary; pH 6.5.95 Al<
C JU
Vel  y dark Krey (1OYR3/1) and
(10VH4/2) moist and light brownish
J gam___ blocky sticky; few
t1. hat_ approaches sandy__loam; weak 
br eak ing siightly plast ic;
to weak medium granular slightly 
‘laik greyish brown grey (10YR6/2) dry 
coarse subangular
med i uni
nonca1cureous, siuool ii boundary ;
and common 
pH 6.8.
very friable moist, soft dry common fine tubular pores, fine and medium roots; clear
c in
Dark        greyish        brown        (10YR4/2)        moist        changing        to        dark brown (10YR3/3) moist with depth, and pale brown
10YH6/3)      dry;      1      oain;      weak      medium      und      coarse      subangular blocky;       slightly       hard       dry;       few       medium       and       common       fine tubular           pores;           noncalcareous;           few           fine           roots;           clear boundary; pH 7.6.
Ckl 75       I ! 5 cm
Brown to (I0YH6/3) plastic, large (3 
; > o w de r y f  kJ 115160 cm
dark brown (10YR4/3) moist and pale brown dry; loam; massive; slightly sticky, slightly 
very friable moist, hard dry; few, small to 15 nun), very hard lime nodules; few pockets of
lime; calcareous to strongly calcareous; pH
k' nun |is .
Biown  to  dark  brown  (10YR4/3) moist and  pale brown (10YW6/3) dry; fine sandy  loanr massive; nonsticky nonplastic,  very  friable moLSt,  slightly  hard  di y  <-w, small to  large (5-20  mm) ,  very  hard  lime nodules; pH 8.5.
»    r.       i c based on auger
samples below 50 could our
«           1 be done b-y" ' 
dui . , „ "...
ce.entatror. samp led.
of
S ”U bv
‘J.
- QI_L JTYfJL E - MOLLIC GLEYSOLS
S
- n»• r a 1 characteristics
IUuterial
**  uphy :
, 
volcanic ash
f
Redrposited (alluviat Gently sloping plain at t e escarpment; 1~3% slope.
anr/cVui ion:                     /H0« 18/2 m
t’I
l )dU'3,'L
I
i       jihi       I       Annual       roinf 2j
about 750 
S< *p t **iuL>c r ; tLioughout
m e a n 
u
daily no frost
.face J vldfh* “ ... (al
al
of
“"ly:
e r os i
I «*n<i u .. •
the year;
( i 1yJ UFa £ n 
Nil
nun, mainly dui ing June to temperatures 17.5-2PC
a
N o n e observable Dry farmed to alid red
mainly iir.iizr, uorghum, i«-f
pepper; f
mainly Acacia and Ficus
few trees and bushes of spvrirs.
j,                Typ i< ** 1 _J2X°fJ-lP
f (| .                       About 250 iu south southwest of the Woja Inver
bridge        near        Koshc        village        along        Zwai        But        ajira        road: u p p r o x .         8° 0 1 ’ N and 3 8” 31 E (obs. site B u t/123,
in 
u
<        ulti        voted        field        with        maize        crop,        on        about
I . 5*<> slope).
Profile descript ion
15 < m
Very
b rown crumb
III o i s t
t ub u 1   ar
dark grey (
10 YR to 2.5Y3/1) ido ist and             dark greyish
( 10YR4/2)            dry;           loam           weak medium
sl i gh t 1y
• slightly       hard dry;
sticky, slightly plastic, few medium
grailular to very friable
and many fine
pores:                                             noncal careous; many fine             and medium
■|> I- ?o
r oo t s     • clear smooth boundary; pH 7.2. cm
10YH to 2.5Y3/2) dry; 1 oamj
s1ight ly
weak
moist and 
med l urn
dark greyish 
granular to
sticky, slightly plastic, 
slightly          hard          dry;
few medium and 
pores;
noncalcareous; common fine
'■‘’It 30
Very 
l*r o u n subungul ar v e r y
«'o union
r o<) t ;
111) c in Very faint
I num;
mn i s t
t dbu I     ar
dark grey 
( 10YU4/2 ) ____ • blocky; friable moist,
fine t ubu1 ar
gradual smooth boundary; pH 7.2.
dark  greyish  brown  (2.5Y3/2) mo  is . to  distinct very  dark  grey  to  ac ' weak  medium angular blocky,  stic y, 
common medium
ido11 les, pi astic, 
f 11 ID
very hard
porv» I es;
many very fine
line routs
r!e,f I 1 0
gradual bound 17 5 c iu
Dark
----- lary;
dry; common  fine and none a I careuus; common
pH 6.7.
moist gFeyish bro*  < -
n
•            many             medium faint
2  5Y4/2 f tO l4/3;oandd?sHnlil0Y“n-.ellow -nd yellowish brown mollies. h,uw
'liiky. slightly plastic, friable moist, 
^oncalcureous, calcareous in pockets: pH 7.5.
Siignih hard dry
t>,ua
lv
p<>* 
own 1° dark brown (10YR4/3) moist, common medium Bl °nt yellowish brown mottles; loam; massive: slightly
M ck Y » slightly plastic, friable moist, hard dry; few S  ’ll t° large (3-20 mm), hard lime nodules; many 
 | «. of powdery lime; calcareous to strongly 
calcareous; pH 7.8.
hc 1
u 7 P
The description below about 50 cm is based on auger samples; augering could not be done beyond 185 cm depth because of a lime-cemented pan below, not
suiwp led.
\ • •               An_a 1 y t i ca 1 da_t_a
1,1  the lol lowing laborut ox y analysis made on -
, -
tji l'< ire presented the results ot
sQil ‘a|liples collected from 6
^ nd ( which
typical profiles of soil types A ’ " ‘
Iiav. been just eleset ibed. The charae eri- <
m the Soils Laboratory of Waler llesuurces Development Addis Ababa, include:-
il Texture, by pipette method; internal ion ii ) Or ganic carbon content
Hi) Calcium carbonate (lime) cont^
” J hat were s t ud 1 <•>!
. 
t  Authority
v) Electrical conductivity soil water suspension
vi) Exchangeable cations
IV) pll, in 1:2.5 soil-water sQSP®
(
O5°C. in 1 2-5
, rFC
vxi)          Cation exchange capacity (Ct J Exchangeable sodium percentage
*•*) Percentage base saturation
t
may be noted from
cations determined
the         table         that         the         sum
of
‘ a,,«‘-oLl
e
< i c * i i /
— — —— —— —•- — —
IS
far higher than the cation 
r i •,                   kCL’C) which is probably due
N an error
in the
in
1  « t ,
f°11        owed 
by             the
laboratory 
the laboratory for these determ 1na11ons. 
for
these
L,le
 sum
’J i . ..»,<. r .*ra;i i ii
ueio—-
of exchangeable cations should always remain1
•Ml *1
€ .prw
<1
1P'» 1
• ? H
rp *
•»'«r q jn jflp
• j j<»da i
|»w1
JO
• »M I I
I
.<n i i|*
P‘»
|CW
1
i
*;
* i ♦*♦**
» /•* t»            T            )       VI
♦ *• a*O F«OA ’ *"«T i • «ut >l| i
JO         A I t 31
•If    »
•*         t > , <0 •»«* j 4              J «         L«
pa v
*!•*<
|r«»!tr« -qi
wo tvtpjoy.M
!• •         .»pr r* VI* <   P"
I r
*
♦* •
4*0 40(04 ffF 40 O                   J30
*
H»
ptir
u
♦w »l<f»
• 1*1'
«• ti<i i 1
J
oi a*’
i*
1I
; •»• I
o' I
Jv
.IS ‘
fi
«• 0*1*          (•      |0 »      0 4<|M j«t
-J J J 1  r "
M
□01
1.1. > J(!1
I•a ’
ft
i v 
 • 
k
• < , *4
Or               p •»rtr' I* >
• OOOO        11 • *M 1
I fl “* ‘
nHi(meq/aOO g £
'a! w
Loam
Loam
1.96 
1.01
0.85 
0.41
0.23
0. ’ll
26.4     18.B
10.6
But/10-l
But/I0-2
27.0     19.2
Silt I^oam
14.3     13.2
But/10-3 
But/JO-M
45.6      26.2
But/10-5
2Btgl
0-15 
15-34/36 
34/36-40/43 
40/43-65 
65-108
Silty Clay 
Silty 
Clay Loam
0.12
0.38
0.12
20.6
21.9
12.3
38.4
38.7
46.2      29.2
Clay Loam
38.6
37.6
35.2
31.0
But/10-6
But/10-7
But 10-8
2Btg2 2Btxk 2BC
108-150
150-166
166-220
Loam
47.3      29.8
Loam
50.1     30.1
11.1
10.6
10.6
11.7
11.9
9ut/89-l
But/89-2 
But/89-3
But/c9-4
Loam
20.9      21.5
E
2Btl
Loam
10.8      11.3
39.3      26.5
2Bt2
0-18 
ie-35 
35-61 
61-90 
90-155
Clay 
Clay loam
Clay loam
2.40
0.96 
0.87
0.26
0.21
0.43
0.11
0.04
0.08
0.31
0.06
0.11
19.0
9.1 
34.4
36.0
33.6
41.0      22.2
But/e9-5
2Btg
38.6     29.2
13.5
11.3
But/126-1
Ap
0-20
20-37
lioam
26.6      20.7
But/126-2
A3
Clay loam
29.7      24 .4
But/126-3
Bxgl
37-78
Clay loam
1.46
0.81
0.76
0.31
0.09
0.21
0.08
0.10
24.5
27.5
27.2
29.6
29.6      23.0
But/126-4
Btg2
78-102/110
Silty clay 
loam
34.0       25. 4
But/126-S
Etg3
102/110-
Clay loam
0.08
32. U
36.7      28.0
146/148
126-6
145/146-220
Loam
o.ou
29.6
34.3      25.8
i13
14
15
16
17
18
19
20
21
22 1    23
24 1     25 \   26 \
/ But/121-1 Pp ' But/121-2/Ah 
But/121-3 
But/121-4
But/121-5
/ 0-16 / 17 / 22 / 16-53/63 / 20 17 / 53/63-63 18 18 I 63-103 15 11 1 103-137 12 12
7
3
4
2
6
|45
40
40
28
30
39
40
38
46
40
17
20
22
26
30
Loam
Lsam
Loam
Loam/ Clay loam Clay loam
1.87 1.20 0.81 0.80
-
1.1
1.8
1.6
2.8
3.2
6.4
6.6
c. 8
7.0
7.6
0.06
0.06
0.02
0.21
0.20
27.2
31.7
28.5
41.9
40.0
1.0
0.5
0.6
0.6
1.6
0.3
0.4
0.4
1.3
3.5
1.8
0.9
o.e
1.4
2.1
30.3
33.5
30.2
45.2
47.2
25.1 1
26.1
25.0
31.2
28.1
5.9
2.6
2.6
3.1
4.4
7.2 1 3.4
3.2
4.5
7.5
6.5 \l0
3.0
2.9
3.8
5.9
0 1 100 ' 100 100 100
But/68-1 
But/88-2 
But/88-3 
AB/Bw Sw
But/8P-4 |5tb But/68-5
but/127-1
Eut/127-2     Btg! But/127-3 Bxg2 But/127-4 Etgb
0-17
17-71
71-81
81-110
110-152
12
8
9
13
10
19
17
6
11
21
16
13
8
3
16
47
38
23
27
47
35
41
49
45
39
18
21
28
28
14
Loam
Loam Clay loam Clay loam
Loam
1.94 0.54 0.48 0.41
-
1.4
1.1
1.6
3.2
4.4
7.6
7.4
7.3
7.0
7.4
0.09
0.10
0.07
0.20
0.10
27.0
23.5
31.6
41.9
50.6
1.0
0.5
1.1
0.6
1.3
0.3
0.3
0.5
0.6
0.5
2.6
0.1
1.8
2.1
2.1
30.9
24.4
35.2
45.2
54.5
25.6
21.1
27.1
30.5
41.3
8.4
0.4
5.1
4.6
3.8
10.2
0.5
6.6
6.6
5.1
9.3
0.5
5.8
5.7
4.4
100
100
100
100
100
0-18
18-56
56-81
ei-ieo
10
10
2
15
11
8
5
10
8
4
10
11
29
22
17
36
44
37
47
37
27
41
36
27
Clay loam/ Loam
Clay
Silty
Clay loam
Clay/
Clay loam
2.04
1.86
0.26
2.8
3.9
2.1
3.6
6.6
6.8
7.0
7.2
0.12
0.14
0.08
0.23
23.7
33.1
37.0
36.4
0.6
1.0
1.8
1.4
0.2
0.5
0.2
0.6
3.4
4.3
5.0
1.0
27.9
38.9
44.0
41.4
24.7
30.1
29.9
35.1
12.: ii.:
11.
2.4
13.7
14.2
» 16.7
2.8
12.9 12.6 14.0
2.6
100
100
100
100Tab!e  M: Available water capacity of soil tyj>es M , B2 and B3
/ Soil
/ Type
Sample
No
Soil horizons repre sented
Depth
(cm)
Moisture
Content (g/lOOg dry 
soil) at
Dry bulk density (g/cm )
;
Available water
(mm/ dm)
pr2.5
pr4.2
Total
Avail. 
water
(mm)
Al
B2
B3
But/84-2
But/84-4
But/84-5
But/121-2
But/121-4
But/121-5
But/88-2
But/88-3
But/88-4
Ah+E*
Btl
Bt2 Availabl
Ap+Ah
Btl
Bt2
Avail abl Ap+AB Bw/Bt
Btb Availably
O-MM 31.11 44-66 U6.71 66-98 32.10
e water upto 1 m 0-63          34.81 63-103      36.32 103-137    38.87
2 water l    pto 1 TH
0-71         37.M5
71-81           39.11
81-110        M2.95
2 water u
pto 1 Jn
22.33        1.17 35.78        1.42 27.76        1.31 depth    =   90 mm
25.05        1.04
24.09        1.12
3M.00      1.16
depth    =   115 m 27.27        1.23 32.32        1.35 32.53        1.15 depth |  =   121 mm
m
10.3
15.5
5.7
10.2
13.7
5.6
12.5
9.2
12.0
37
34
18
6M
55
19
89
9
35
11
* Horizon E could not be sanpled due to its unstability for core sampling; the available water content of this horizon is taken as 50% of that of A horizon.

Summery

Butajira Project Area Summary

Butajira Project Area: Soils and Land Suitability for Irrigated Agriculture

Project Overview

The Butajira Project Area represents a cooperative initiative between the Government of Ethiopia, the Food and Agriculture Organization (FAO), and the United Nations Development Programme (UNDP) to develop irrigated agriculture in Ethiopia. The project focuses on a 2,130-hectare area near Koshe village along the Woja River.

        Key Findings
        74% of the area (1,572 ha) is moderately to highly suitable for irrigated agriculture
Only 143 ha can be irrigated by gravity; the rest requires pumping
Soils are generally very fertile but have permeability challenges
Optimal for food grains, vegetables, pulses, and some orchards

    

Soil Characteristics

The area features deep soils formed in volcanic ash overlying weathered ignimbrite. Key soil types include:

Soil Type	Classification	Key Characteristics	Drainage
A1	Mollic Planosols	Thick dark topsoil, abrupt textural change to dense subsoil	Imperfect
B1-B3	Phaeozems	Deep, fertile, varying drainage conditions	Moderate to well
C1-C2	Luvisols	Clay-enriched subsoil, varying topsoil thickness	Moderate
D	Chernozems	Calcareous subsoil, good drainage	Well

Land Suitability

The land was evaluated for irrigation potential at medium and high input levels:

Highly Suitable Crops

Food grains: Wheat, barley, maize, sorghum, tef
Vegetables: Potato, tomato, onion, cabbage, carrot
Pulses: Haricot beans, chickpeas, lentils
Oilseeds: Sunflower, safflower

Management Recommendations

Subsoiling/chiseling to break up dense subsoil layers
Shallow drainage systems (60cm depth) for waterlogged areas
Contour farming/terracing on slopes >1% to prevent erosion
Precision irrigation to manage water application
Gypsum application every 4-5 years to manage sodium levels

Climate and Water Resources

The area has a mean annual rainfall of ~750mm (60-65% June-September). The Woja River provides suitable irrigation water (EC 0.28 mS/cm, pH 7.4). The proposed dam would store 60 million m³ of water.

Conclusions

The Butajira Project Area shows high potential for irrigated agriculture, particularly for food crops and commercial vegetable production. Key limitations include subsoil permeability and drainage issues that can be managed with proper techniques. The project recommends focusing on high-value crops and implementing proper water management systems to maximize agricultural productivity.