The People's Democratic Republic of Ethiopia Water Resources Development Authority IRRIGATION AGRONONY REPOR T JUL Y - AUGUST 1989 FINAL DRAFT AMIBARA DRAINAGE PROJECTI Sir M. MacDonald & Partners Limited Cambridge, England LIST OF CONTENTS I. ITINERARY AND WORK PROGRAMME. 2. RECTENT PRODUCTION TRENDS AND 2.1 Introducti.on. PROJECT MONITORING. 2.2 Production Trends on the Melka Sadi State Farn... PAGE 1 3 3 2.3 2.4 2.5 2.2.1. Cotton yields.. 2.2.2. Banana yieldls. Cliuatic Data. Groundwater Levels and Soil 2.6 Irrigation Wuter Irrigation Water Quality. Supp].y. Salinity.. 5 5 6 3. IDENTIFICATION OF FACTORS 3.1 LEVELS... .. LIMITING CROP PRODUCTION 3.2 The Incidence of Introduction.. 3.3 The CAUses of Soil. Soil Salinity. 3.4 Resource Limi tations. 3.4.1. Water supply. Salinity. 3.4.2. 3.4.4. 3.4.3. Machinery and Availability equipIent. 3.5 Husbandry Lii tations. 3.5.1. Bananas 3.5.2. Cot.ton. 3.6 The Ai bara Settlement Project. Humar resources. of capi tal. 4. FUTURE 4.1 Objectives and AGRICULTURAL DEVELOMENT 4.2 Land Levelling. Policies. REQUIREMCNTS 4.2.1. 4.2.2. 4.3 Land RecluAt ion... 4.2.3. Options for Background. ExtenL of land levlling requireernts. land levelling. 4.4 4.5 Tuuprovenient or Husbarndry Practices. Tnuproveienl of Lund Preparation arnd Crop Water Managelent Practices.. 4.5.1. BnanAS. 4.6 4.7 4.8 4.5.2., Colt.on Agronoic Triul PrOgrunue. Training. Auibaru Settleuent Projcct Plunning. 14 4 14 5 18 18 19 |9 19 21 21 21 22 2-1 24 26 26 28 28 28 29 30 30 31 32 33 34 LIST OF CONTENTS (CONTD. ) 5. PROPOSALS AND RECOMMENDATIONS - ACTION PLAN FOR 1990. 5.1 Project Monitoring 5.1.1. Soil salinity monitoring. Improvenents and Innovations.. 5.1.2. Aerial photography. 5.2 Definition 5.1.4. Monitoring of Size and crop Scope production of Land levels. Levelling 5.1.3. Nonitoring water quality. 5.3 5.4 5.5 Applied Research. 5.5.1. Leaching and land reclanation. 5.5.2. Bananas Water Managenernt. Observations and Measurenents. Observation on GroundWater Fluctuat ion. Requirenents. 5.5.3. 5.5.4. 5.5.5. Inplementation of a crop trial programne. Cotton. Miscellaneous trials... PAGE 36 36 37 37 37 37 38 38 39 39 39 40 41 -11 42 PRELIMINARY RIEVIEW OF TH IE BY ÞTHCR ORGANISATION. IRRIGATION AGRONOMY REPORT 6.1 Distribution of the Report and 0bjectives. 13 13 LIST OF APPENDICES APPENDIX NO. 1 2 Comnents on report by Institute of Agricultural Research Comments on report by Project Control Centre LIST OF TABLES TABLE NO. la 1b 2 3 3a 3b 3c 4 Mean Yields of Seed Cotton at the Melka Sadi State Farn by Management Unit and Some Results of Statistical Analyses 5a 5b 6a 6b 7 Melka Sadi State Far1 Cotton Production Banana Production at the Melka Sadi State Farm Monthly Rainfall Data from Statiors in the ADP Stage 1 Area IAR Agroclinatic Station PCC Agroclimatic Station Pilot Drainage Trial Rain Gauge Nunber of Piezoneters by Depth to Water Table Ranges Illustrating Fluc tuations in Groundwater Levels Betiween 1984-89 Annual Suniary of Irrigation Wuter Supplied to the Three Users in the Anibara Irrigation Area Mean Annual Quantities of Water Delivered Through Prinary Offtakes to Melka Sadi State Far1n River Water Salinity as Monthly Mean Electrical Conductivity Actual Measurenents of River Water Salinity as DC in InS per cl Inventory of Paru Machinery at the Melku Sadli State Furu, July 1989 1 ITINERARY AND WORK PROGRAMME The Alaba the following day and travelling on to the Amibara Project on July 14. He was on site until August 3 when he returned to Addis Ababa and left for the UK on August 4. The ters of reference for the Irrigation Agronomist which are set Out in the Technical Proposal which forins the basis for the Irrigation Agronomist left UK on July 10 arriving in Addis Consul tancy Agreenient include the responsibilities: Contract following a. Reviewing present crop production practices to identify crop yield limiting factors. b. C. Assenbling crop production data, related to soil condi tions for establishing priority areas for investigation. Cstablishing a inonitoring system for crop yield assesSINernt in relation to soil conditions, irrigation Water quality and water nANagenent. d. trial on vertisol soils. e. Following land reclaation Assisting wi th the selection and plarning of pilot drain preparing cropping patterns, Outs. irrigation scheduling, land nanagenent. technique und f'icld lay f. Planning und supervising iplenentation of tield t.rials effects investigate alternative Iethods of surface irrigation to levels and crop yields. of variable irrigation schedul ing on soil Salini the t.y covered by the In addition to these terms of reference a list of provided by the Irrigation Agronomist during his several visits priorities to be follows: Consul tants Supervisor and Teaun leuder which were as Were investigate the scope for a second crop identify the need for improved Wiater IrayenenL scheduling for levelling/planing - various growth sLuges. layers, inler-row recouMhendutions. equipuent, subsoiling, cOukcL [Xrtieulurly soil leaching progrulmes iuproved land prepuration crop husbundry/banauA IAnugelent IIoniLoring systen 1'or crop yields Both sets of ters of overlap Lo conprehensively tuckled in this fi rst visit. lurge (:xLent. Lhey obviously relerence ure wide ranging nd whilsL Lhey COulu 1 The basic ains of this visit have been to obtain an understarnding of the situation in the Stage I area in the broadest sense and to identify priority areas for action. Dxisting information and datu on all aspects of crop production have been exanined. Institutional and organisational responsibilities relating to the project have been established. Meetings have been held with managers in MAADE, IAR and RRC to es tablish a working relationship and to take advantage of the accunulated knowledge on factors limiting crop production-levels. This report includes a brief suunary of the findings of the initial visit of the Irrigation Agronomist to ADP in July 1989. The timing of this visit Was most opportune in so far as it was possible to see clearly the problens of unlevel fields and the problens of Soil salinity which were obviously well defined in the cotton. However, with the crop already well establi shed there is only linited opportunity for investigational work and in any Case the organisational, logistical and funding couplications rule out any inunediäte actiorn. Consequently the proposals contained in this report refer to the consolidation of existing moni toring procedures for the 1989 cotton crop whilst for 1990 a uch wide range of activi ties could be possible including land development estimates, field investigations and crop trials and the introduction of MOre sophist.i cated systems of monitoring. 2 2. 2.1 2.2 2.2.1 RECENT PRODUCTION TRENDS AND PROJECT MONITORING Introduction In order to have a proper understanding of the existing situation it is necessary to up date the report entitled 'Master Drainage Plan for the Melka Sadi and Anibara Areas' This report was published in July 1985 but much of the data presented covered the period up to 1983 whilst some of the production projections used were based on assessnents of the iunature 1984 crop. Since 1984 a further period of five years has elapsed in which a considerable anount of data and experience has accuiulated. This accumulated infornation has rarely been analysed although it is a vital ingredient of the planning process. Within the Stage 1 area of ADP there are four divisions of the land which are under four district nanagement systens: the Melka Sadi State Farn (4205 hectare irrigable); the Melka Werer IAR (300 ha); the Amibara Settlenent Project (2000 ha); the Melka Werer State Farm, (500 ha) In examining recent production treIds the emphasis has been placed inevitubly on the Melka Sudi State Farn, the khole of which is within the Stage 1 area. Conditions on the IAR ae atypical of the state farns. The Anibara Settlement Project does not keep records of eropping and crop production. Parts of the Melka Sadi State Farn are representative of the small area of thee Melka Werer Stale Parn within the Stage 1 area and it was cons idered unnecessury to duplicate. The Melka Said S tate Farn is situated at the heud of Lhe Anibara irrigation system and includes areas which have been irrigaled since Lhe lute 1960's as well as areas which were develod s late 1984. This farn includes substantial areas of ubandoned land ud is therefore suitable selcction for more delailed sLudy. Production Trends on the Melka Sadi State Faru Cotton yields Yield data has been collecLed at the individuul Cield level in Mulka Sadi since the beginning of the project in 1984 ard this dutu been carefully anualysed. The Ieun yields by AmgelIent hus irrigation unit ure presented in Table lu lor the 1'ive yeur period 1984-88. In the 1'irst three yeurs uCCOrding to .he:see slutist.ics overall mean yield decreusd by 20% und this Was lollokel by rCCOvery in 1987. Ilowevr in 988 there wuN u drsLie dK. ion in product.ion levels when Lhe averuge yield S Only 60% of the 1984 yield. Slalistical unalys:5 Were undertaalen of Lhe yield haa for zeh ot' Lhe seven nils. The dil'lerences la:Liveen the tal Lutwe1 Tiuld meAns Were siguil'icanl in all seveu unils . l(SL ul. .he S% level wi Lh L: usjorily of inter yur dirrerCOS SiguiliCnt. ul. tle: 0.1% level. Were wilhin ICCHptable 1 iuiLs wliich suporl.s Lhe 0:luSion hal The co:'ficivnls of vuint. ion ol the yied lata busic cbatu i reusUubly ruliublu. e 3 The conclusion that the challenged on two points. The first is the farm data contained in field yield data is reliable ay Table yield lb which shows a more regular but accelerating decline be in da ta. In the latter, fields which are known and the second stems from an examination of individual field to be seriously affected by soil salinity do not give appropriate yield reduct ions Or the pattern of yield reduction is not one of gradual reduction but a which catastrophic fall have been obviously wrongly recorded is relatively sIal] in production. However the number of fields arnd do not seriously affect a ficld production level may be attributable to fuctors other than overall conclusions. A catastrophic fall in soil salinity. There is an obvious trend of declining yields of cot ton on the Mellka Sadi State Farn based on an examination of the last 5 years of data. Field observations suggest that this trend is due largely to increasing soil salinity and unless sone action is tken to reluce 2.2.2 and control soil salinity levels yields will continue to decline. Banana yields The bananaA area at Melka Sadi State Farn was develoj*d in the late 1960's and the available production figures which are for he period 1975-1988 are contained in Table 2. These statistics denonstrate that the nanagement has been in a losing battle to the survival of the shole halt. delining banana operation production levels and land abandonent ~und Inust be in danger. Indeed in 1989 tlie productive Area of bananas has fallen well below the 440 now Lhat was maintained lor the previous lour years. The basic probleu with the bananu area has been one table which has led to 'heavy salinisation o!' o1 the tojsoil. hex:tul'es r'ising Other najor Constraints have include of uncont.rolled weed growth, and inadequate fert.ilisation. lack Irolation, 2.3 Clinatic Data Clivatic data hus been exnined for exceptionul events were lurgely confined o ruinfall. Rinlal| datia Lhe 3 year .id is presented in Table 3 lor 3 s ual.ions. "The tvuin l'eature of this data is the extru ordina'y difrerence lelieen he Lhree stalious and explaunLions for purt.iculurly Lhe much higher ruinfall rOrdd at 1AR. Possible this Vuriubilily is give1 in AP[lix of this rejor. . OLher itX)rLeul. Iuinlal| in Lhe lnst Lhree yeurs whicth is lau'gely uXOUnLxl lor by ainfull lealules of Iol: inoliak: Ll: at: ve the exceplionul ruinlall in Lhe short. rains ebraU'y, NLArch ual April giving a narkedly hi-lKxdel listribut.ion. Llal Iuinlnl| of Lhis 4romlwaler levels. Iie eNCeptional ruinlall l«lly in Augus IiaguilLu houll mv I988 when 262.4 u We reOrlel Dxu so probleus o! il logyin! und r:stried oporlunilies lor Lhe plicat ion o insieide which rducnl Lhe colLo Crop Droel.ion xlLial. 2.4 Groundwater Levels and Soil Salinity Data from 71 piezometers that were installed in 1984 have beern examined. These piezoneters are located in a random manner but give good coverage of both the Melka Sadi and Melka Werer State Far1s. A broad indication of general changes in groundwater depth is illustrated by the data shown in Table 4. In this table a gradual trend towards higher wat.er table levels can be detected but there have been no massive pernanent changes as were once predicated. Indeed there are no piezometers showing consistently high ater tables of less than one netre. It should however be rointed out that. January and June may not register the highest Hater table levels recorded through the year. The piezome ter data also demonstrates that water table fluctuating often by 1 or 2 lMetres and oCCasionally suggesting that some natural drainage is taking place. levels IOre , are thus The largest rise in water table levels occurred in June 1989 ivhen 49.2% of the piezoneters registered water table levels of less than 3.0 compared with 36.9% in June 1988. There is no ready explanation for this nost. recent. change. High soil salinity levels are cOMIon ly associated with groundwater levels and this is siuply demonsLrated by high the abandoned saline areas of the banana urea on the Melka Sadi State Fuu. Unfortunately no routine nonitoring of soil sulinity levels has been undertaken SO that there is no delinite proof of t.he correlnt.ion between groundwa ter level and soil salinity where the Waler table is nore than 1 m below the surfnCe And the extent of trans1nission of wuter to t.he surface by capillary uncerain. is Vary frou area to areu and general conclusions ure dilficul t. Iust be acknowledged hOWever LhaL the events (irrigat. ion Irequency, field reinsatement ete.) der which lata is collei to 2.5 arrie al. A coDprchensive analysis of srdvater depth in conjunction with lund use detuils might derive lett.er colusiotus - (see Appendix 2). Irrigation Water Supply The laLa on Lhe qutnt.it.is of waler ASSd lown h: Iain cuunl ullocall lo Lhe prinary offakes huve lan Niunind wil1 Lhe oljec:Live:s ol' givig a broul inticalion of yor lo yeur lul wliun iI Wat.er use and Lo oblin sOe s.iwlS o the aelal 5 In Table 5a an annual suInary is presented of the Iwater made available to the three main users the Middle Awash Agricultural Enterprise, the Research Station and the Amibara Settlement Farm. Annual water use shows little correlation wi th rainfall in the irrigated area. However the low figure for 1988 was due to low river floWS caused by low rainfall in the River Awash catchnent area in the Central Highlands - dependence on run of the river water supply may explain the absence of any correlation between irrigation water use and rainfall. The low 1988 irrigation water quantity ig also because a considerable area remained unplanted because of the general Water shortage during pre irrigation and planting periods in that season. In Table 5b the mean annual quantities of water delivered through the primary offtakes serving the Melka Sadi State Farm are presented expressed on a per hectare basis. Rainfall data is also included in Table 5b so that the total anounts of water available for the cotton can be calculated. No fin conclusions can be drawn fron1 this data but it is suggested that, with a net requirenent of 8200 Cu. per ha for cotton, in many instances there is the tendency for over irrigation. However irrigation quantity fluctuations from year to year could be attributed to the policy of State Farns to try to introduce double cropping. (See Appendx 2). 2.6 V Irrigation Water Quality The routine recording of Awash river water quality began in June 1987. The electrical conductivity of water sanples taken rom the Amibara main canal headworks are being measured four times a IIonth at more or less weekly interval_. In the period June to December 1987 there was little change in the electrical conductivity of the water which varied between 0.34 0.40 IS per CIll. However from the beginning of 1988 gradual increase occurred which continued to a peak monthly mean of 0.88 ms per cm in June and an overall peak of 1.04 nS per cm in the first Week in July. These high figures coincided with exceptionally prolonged low river flows in 1988. quantities of According to the USDA classification of irrigation the Awash river water Imay be generally classified as C2 salinity Water which can only be used on a long tern basis IIOderate aOunt of lCaching occurs. For shor. Deriods quality nay improve to an ECe of less than 0.25 S er cal. Water salinity in 1988 there was A period when water quality noved inl.o the c3 category described as high salinity water in which ECe exceeded 0.75 IS per CIl. This ocourred during the peak irriution a:rixd for cotton, (but see Section 3.4.1). medium if Wate However LE la: MEAN YIELDS OF SEED CO1ON AT MELKA SADI STATE FARM BY MANAGEMENT UNIT AND SOME RESULTS OF STATISTICAL ANALYSES MANAGEMENT UNITS YEAR 1 2 3 4 5 6 7 1988 28.1 21.7 20.9 24.6 23.7 22.1 24.0 ANNUAL. MEANS (QUINTALS PER HA) 24.0 1987 31.1 33.9 31.9 31.2 30.8 34.9 1984 37.8 32.2 32.0 42.8 42.7 31.7 1986 1985 35.5 32.1 31.5 26.4 30.9 32.3 31.1 34.8 38.9 5 YEAR MEANS DARD DEVIATION 33.3 6.79 36.8 31.3 7.24 16.1 33.5 29.5 8.94 33.1 29.4 31.8 35.2 30.8 6.50 34.7 9.15 34.8 29.4 6.09 35.8 31.1 34.8 38.9 32.9 7.71 S OF SIGNIFICANCE ERENCES BETWEEN AL MEANS RENCES BETWEEN D MEANS *** ** *** 7ICIENT OF VARIATION 16.1 13.2 MAAEOffice = Significant at 5% level = Significant at 1% level = Significant at. 0. 1% level Fields that were abandoned and not 22.8 13.8 ** 12.35 12.2 ** 14.4 in these analyses productive were not included lb: MELKA SADI STATE FARM COTTON PRODUCTION AR 88 87 86 85 AREA OF C TTON GROWN IN HA 2633 2633 2633 2233 TOTAL PRODUCTION OF SEED C TTON IN QUTNTALS 81671 95108 103808 91000 7 AVERAGE YIELD OF SEED C TTON IN QUINIALS PER IIA 31.0 36.1 39.4 40.7 3LE 2: BANANA PRODUCTION AT THE MELKA SADI STATE FARM (EAR ARCA OF PRODUCTIVE BANANAS HECTARES AREA OF LAND ABANDONED HCCTARES CUMULATIVE TOTAL AREA OF LAND ABANDONCD HECTARES 1975 1976 1977 1978 1979 1980 1981 1982 1983 * 1984 * 1985 1986 1987 1988 720 700 700 733 706 700 700 700 280 400 440 440 440 440 30 20 97 103 190 77 80 115 213 233 233 330 433 623 700 780 895 260 1,155 TOTALL ANNUAL PRODUCTION IN QUINTALS 171,641 15,910 108,050 106,637 102,370 84,353 80,000 80,422 37,602 12,433 51,069 48,157 23,051 21,307 AVERAGE YIELD OF PRODUCTIVE LAND IN QUINTAL PER IIECTARE 238.4 271.0 154.4 145.5 145.0 120.5 114.3 114.9 134.3 28.3 116.1 109.6 52.4 48.4 The catastrophic reduction in area between 1982 and 1983 was the result of serious drought in the region and the estate was invaded by local livestock herds for survival. Subsequent re-planting of much of the bunana area neant that 1984 production and yield levels were extremely low. TABLD 3: MONTHLY RAINFALL DATA FROM STATIONS IN THE ADP STAGE 1 ARCA 3a, IAR Agroclinatic Station 1984 1985 1986 1987 January February March April May June July August Septenber October Novenber December 0.0 18.2 0.0 0.0 9.6 0.0 16.5 80.5 33.7 144.6 63.3 70.0 0.0 2.0 4.1 7.0 85.5 39.1 0.0 155.6 123.9 59.5 0.0 0.0 2.0 99.1 83.0 43.2 54.3 59.1 107.4 67.1 114.6 5.2 0.0 0.0 0.0 37.4 167.5 95.6 43.7 0.8 36.3 136.3 34.5 7.6 0.0 0.0 1988 0.0 56.6 21.1 110.9 5.7 27.6 107.2 262.4 80.1 8.8 0.0 1.8 TOTALS 424.3 490.8 633.0 559.7 685.2 MIEANS 3.6 38.6 58.2 70.3 44.7 2-1.2 110.2 130.G 71.7 4.3 0.4 1.6 558.4 LONG TERM AVERAGE 1965-83 8.8 51.6 50.7 91.7 30.8 19.9 106.8 135.2 31.1 19.2 12.9 1.3 566.0 3b. PCC Agroclimatic Station January February March April 1985 1986 0.0 0.0 0.0 0.0 0.0 0.0 127.4 42.3 47.9 0.0 1.8 1.1 1984 13.2 12.0 65.4 62.1 3.7 164.5 85.4 23.1 1.5 0.0 1.6 1987 0.0 37.3 45.7 May June July August. September October Noveuber Decenber TOTALS 39.0 11.8 50.6 60.4 37.4 61.7 0.0 19.1 105.2 11.2 24.0 0.0 26.7 67.2 16.7 11.7 0.0 0.0 1988 13.8 38.0 11.3 45.0 5.5 6.1 76.9 158.9 51.3 9.3 0.0 0.0 MCANS 8.8 18.9 34.8 32.1 20.7 12.1 91.2 78.2 40.1 5.6 .3 .7 220.5 432.5 5.3 0.0 0.0 349.2 281.8 416.1 341.5 3c. Pilot Drainage Trial Rain Gauge January February March April May Juie July August. Septeutbcer OcLoter Noveuber 1984 1985 NO RIECOR) NO RECORID Deceutr 1986 0.0 15.9 32.0 38.3 8.9 G1.7 67.2 41.5 0.0 32.6 0.) 0.0 1987 0.0 10.3 78.7 16.9 34.7 .0 62.0 69.8 18,3 C.5 0.0 0.0 1988 0.0 37.3 9.5 .0 .0 12.5 82.6 107.4 48.6 0.0 0.0 0.0 MIPANS 0.0 21.2 40.1 18.4 14.5 21.7 70.0 72.9 22.3 13.0 0.0 0.0 T TALS 298.1 297.2 297.9 297.7 9 PIEZONETERS NUBER CF RECCRDS WITH 63 PIEZOETERS NUNBER OF NO WITH RECORDS 66 64 66 64 65 64 66 57 7 6 5 7 6 7 5 14 >6.0 (20.5) 13 (18.8) 12 20 (30,8) (25.9) 17 (28.1) 18 (25.8) 17 21 (32.9) (29.7) 19 21 (32.9) (34.9) 23 23 (40.3) 1984-1989 5.01-6.0 ( 5 8.0) 7.8) 5( (6.1) 2( 3.0) 4 (6.3) (12. 8 1) 4.7) ( 3 (12.5) 8 ( 3 4.7) 7 (10.6) (10.5) 6 BETWEEN m. 4.01-5.0 RANGES LEVELS TABLE IN TABLE 4 3(8.0) 4 ( 6.3) (10.8) 7 11 (16.7) (18.8) 12 (15.2) 10 7 (10.9) (10.9) 7 (10.9) 9 (13.5) (7.0) 4 3.01-4.0 7 WATER WATER GROUNDWATER 3) 9 (14. (28.1) 18 (15.4) 10 (21.2) 14 (12.5) 8 (13.6) 9 (17.2) 11 (18,5) (17.5) (15.2) 10 7 (12. 2) TO 12 11 Observations TO DEPTH IN DEPTH 2.01-3.0 (27.0) (28.1) 18 (23.1) 15 (15.2) 10 (23.4) 15 (25.8), 17 (23.4) 15 (18.,5) (23.1) (16.7) 9 (15.8) RANGE IN BY FLUCTUATIONS 17 1.01-2.0 (22.2) 9.4) 6( (13.8) 9 (13.5) 7.8) ( 5 (6.0) 4 7 (10.9) 5 (7.7) 7 (10.9) 9.1) (14.0) 8 12 15 11 Monthly PIEZOMETERS 14 9 6( Total ILLUSTRATING 0.0-1.0 OF (0.0) (1.5) (0,0) (4.5) 2 (3.1) (1.5) 1 (0.0) (3.1) (0.0) 0 (0.0) 0 (0.0) NUBER 0 1 0 3 0 2 0 of % () OBSERVATION 4: TABLE KONTH OF June 89 89 88 June 88 June 87 37 June 86 86 June 85 85 Jan Jan June 84 Jan Jan Jan TABLE 5a: ANNUAL SUMMARY OF IRRIGATION WATER SUPPLIED TO THE THREE USERS IN THE AMIBARA IRRIGATION AREA (CUBIC METRES X 1000) ANNUAL T TAL YEAR MAAE IAR ASP TOTAL. RAINFALL IN MM IAR PCC 1988 1987 1986 1985 1984 MEAN 102,910 143,092 127,531 111,874 125,094 122, 100 2,841 5,210 416.1 4,354 3,078 282.1 1,774 4,819 3,373 12,682 12,744 7,817 12,817 10,254 110,961 160, 128 143,353 121,465 142,730 135,727 682.5 559.7 633.0 490.8 424.3 558.4 349.2 432.5 220.5 341.5 TABLE 5b: MEAN ANNUAL QUANTITIES OF WATER DELIVERED THROUGH PRIMARY OFFTAKES. TO MELKA SADI STATE FARM (CUBIC METRES PER HA) PRIMARY OFFTAIKE NUMBERS YEAR COTTON AREA BANANA AREA CFFECIIVE RAINFALLL 80% T TAL APRIL SEPT IN CU. M PER HA 4 2 LAR 1CC 1988 1987 1986 1985 1984 7,940 11,145 13, 181 13,757 8,330 10,665 9,049 10,424 5,939 3,473 4,457 4,706 11,800 11,596 13,438 12,234 14,751 22,442 15,743 4,090 MEAN 11,565 10,013 10,350 7,209 9,640 12,883 13,463 10,709 15,721 1,533 3,437 1,061 2,609 4,042 2,17G 2,745 11 TABLE 6a: RIVER WATER SALINITY AS MONTHLY MEAN ELECTRICAL CONDUCTIVITY IN mS PER CM SAMPLING POINT MAIN CANAL HDADWORKS JUNE 1987 - JULY 1989 1987 JANUARY FEBRUARY MARCII APRIL MAY JUNE JULY AUGUST SEPTEMBER OCTOBER NOVEMBER DECEMBER MEANS 0.35 0.41 0.36 0.34 0.40 0.36 0.34 1988 0.40 0.47 0.49 0.52 0.67 0.88 0.55 0.24 0.24 0.31 0.41 0.42 0.47 1989 0.43 0.44 0:42 0.38 0.46 0.54 0.48 MEAN 0.42 0.46 0.46 0.45 0.57 0.59 0.48 0.30 0.30 0.3G 0.39 0.38 0.43 * Measuremernt. began lst. June 1987 12 TABLE 6b: ACTUAL MEASUREMENTS OF RIVER WATER SALINITY AS Ec IN mS PER CM 1987 1988 Apr 0.54 2 1989 Apr 0.37 3 2 0.32 MEAN MEAN May 1 2 0.54 0.48 0.52 0.52 0.62 0.64 May 2 0.17 0.37 0.38 0.45 0.44 0.50 Beginning of records 4 0.90 MEAN 0.67 MEAN 4 0.45 0.46 June 2 June 1 2 June 3 4 MEAN 3 4 MEAN 2 3 4 MEAN July 1 2 4 July 1 MEAN 2 3 4 MEAN July 2 3 MEAN 0.52 0.56 0.54 0.52 0.54 0.53 0.52 0.43 0.44 0.48 Aug 1 2 Aug 3 MEAN 2 3 4 MEAN Sept 1 2 3 MEAN Sept 2 3 MEAN Oct 3 MEAN 2 3 MEAN Nov Nov 3 MEAN 3 MEAN Dec 2 3 1 MEAN 0.32 0.38 0.22 0.48 0.35 0.40 0.46 0.38 0.40 0.41 0.43 0.41 0.29 0.29 0.36 0.35 0.32 0.34 0.33 0.34 0.34 0.58 0.40 0.38 0.38 0.32 0.30 0.30 0.30 0.38 0.38 0.34 Oct Dec 1 3 MPAN 0.89 0.81 0.86 0.96 0.88 1.04 0.34 0.28 0.55 0.30 0.21 0.25 0.20 0.24 0.20 0.24 0.22 0.30 0.24 0.28 0.32 0.33 0.32 0.31 0.38 0.40 0.46 0.11 0.41 0.43 0.43 0.40 0.12 0.42 13 3. 3.1 IDENTIFICATION OF FACTORS LIMITING CROP PRODUCTION LEVELS Introduction Production problens have been investigated in soue detail only the Melka Sadi State Parn which can also be assumed to be representative of that part of the included in Stage 1 of the ADP. Mellka Werer State Farm that is The Ami bara Settlement Project presents rather different scenario since it is not being taued intensively and production is very much restricted by factors which are not limiting on the State Farns. its production Thus, because the ASP is a different kind of operation, discussed in a separate section. The Melka Werer Research problcHIs have been Station, the fourth component of Sttage 1 of ADP, is also a special case since it is not production orientated. A review of sOIe of the results of previous investigutions carried out on guidelines on soue of the f'aclors limiting crop production levels. the station provides sce 3.2 The Incidence of Soil Salinity By far the most serious factor affecting production soil levels of both bananas and cotton are the escalating levels of salinity. In the long uyo 1975 and the loss of Melka Sadi banana area land WAS being abAndoned s AS land in the area allocated for bananas in 1989 is in excess of 1200 hectares. Based on observations in the Ciell significant areas of these abandoned lands have bare surfaces where of bananas in 1989 has declined to little nore than 300 hectares the process of salinisation continues. The actual procluctive areu whilst the average yield in 1988 wus less than 5 Lons per hecture. Obviously if nothing is done to halt he process of salinisation of the soil then banana product.ion will cease in the not too distinl Cuture. The cotton aret 1980'. of Mel.ka Sadi cune into produclLion in Since that time a total of 351 hectares had been the early abundoned by 1988. Observations on the 1989 crop suKEEsL that this figure nunber of fields is set to since there are a substauntiul severely affected by soil salinity. increase Averuge cotlon yields sa a very larked drop in 1988 t.o 24 quintals per hecare us cOuJSAI0 wi Lh nearly 35 only [Arlinlly responsible for this druntic quintals in 1987. change. Huwever salini Ly was und t.he As lw yars sugges., distribution of rather pathe.ic Lhe figures for severe soil salini L÷ yield levels of Lh: past the alxndoned lurds in Lhe lsni Ua Llhrogl1oul. nlaost 1.he the whole of the annuuA urcu. Salini Ly in Lhe Col.ton lund uf M:llka Sadi :s unl il "The dist.ribut.ion of is widospreul S(:Vee S0il IWCn.ly COncer1traled in ureas uljucenl. Lo Le LuuwR SLiale ol Soils wilh unixcd Lextures und wilh relulively high waler tabls. llkoev: In. yars JevelS Lo lmds (ar reuOVGd rom he Lxuwal 24 AeL. Llhere hHAs D:en n obvious :NLeusion o Iigli saliuily 14 In the absence of ar1y roul.ine monitoring of soil salini l.y tlie pattern of occurrence is little understood although the recent Soil survey has thrown some light on the nutter. The iOsL sérious ly affected areaS appear to be those1where the profi le is of mixed textures whicl1 includes Lhe banana Area and surrounding cot ton lands. Over Considerable areas such soils ale associated wilh urderlying volcanic tuff which coies Lo within less than 2 n:Lres or the sur face in some areas adjacent to the ain cianal. In 1989 uany Cields along the mA in canal have large bare palches where high salinity levels have resulted in poor establ ishment of the cotton. The soils of nixed textures tend to huve relatively hig waler tables of around 2 n though not so high as to pose an obvious threat. in raising surface soil salinity levels. The lanls with deep profiles of uniforn heavy texture seen to be associated wi th deep 1water tables and are generally not a> fec ted by salinily. More detailed observations are required lo coulir Lhese preli minary judgements. An atteupt is being ade by Stale Furns to obtain SOIe ierial piotogra1s of Lhe 1989 crop and it is hopel that these phoLographs will resul t in salinity. Iè saline areas can be closely relaled Lo soil type tnd other Condi tions a IKOre praguwat.ic approach Lo Lhe draiag: proble MAy be pernitLed. For exanple soil salinity MsAy le relalexl tU Cual IMOre precise delinition or Lhe O:Curence of by seepage, seepnge frou the higher round nbove Lhe priAry Condi tions crented by localised vAriat.ions in soi) Lextures catial, deposi tional dilferences ctc. 3.3 The Causes of Soil Salinity In the Cirst year or twO imuuediately lollo:ing inil.ial of the land on the Melka Sadi Farn, yield levels o oth cdevelopilenl banaAnAS ad CoLton Were satisfactory and compared well wi Lh oher Ethiopia and the world. However a relal.ively short [rts of L.ime aller ne, iu kty landoned. his decline I'ields lalling wus ue quickly Tt developier1t yields begin to de to the point at which lurd wa increasing salinity levels. the cAuses of the increase in suliniLy. clir s a is thercl'ore imLant. Lo idenL il'y There in the Lop soil Lo the Are two possible: causes of the sulLs which lAV: iWXMulalal nol. lnger pOssible. The SallS Ay derive rou Lhe iriga.ion wil* ex Lent. Lhat crop producLion is reducxl or is in Lhe uppe arl. of Lhe profile la:ccAlIS: o cvixrl.ion a. Le surlac: und/or evapxral.iorn Lhrough he (:rop. Iarge quuntil.ies of wLo inlo Lh: inceASi ng COnCenLialios o Sulls in Ll Soil haler. iAppl i d or Crou Le grourdwaler. In LxLli casCS l sal L.s uRAll: Suil hidI 15 Based on the nonitoring of the ANash river water since Jun: the average electri cal conductivity of the irrigation IvaLer 1987, 0.43 275 milligrans per litre. The average calculated evapo-l.ranspiration per CIlI Which is equivalent to total dissolved solids of is of banarus is approxinutely 25,000 cubic etres per hecLare per while that for cotton is about 8000 culbic netres per hectare year, per crop. negligible anounts are renoved by the crop, the anual accumulation Thus assuniing no leaching takes plnce and that only of salts in the upper part of the soil prolile (in erfect in the root zone) will be of the order of 6.8 tons per hectare per annum for bananas and 2.2 tons for cotton. Obviously leuching is critical requirement for the removal of these sal ts as Lhe Water Lable rises into root zone. The rising water table has ulways been secn as the najor CauSe of soil salinity and this is partly because a high Wa ter table restricts the amount ol leaching that CAn take pluce, thus preventing the removal of salts fron the root zone thal. are appliel in Lhe irrigation water. At the sune t.ime the high Water table loses water in an upward direction as a result. of cupillary suct.ion pressures which carry Che water to the surluce. Invariably the grondwaLer has high salt con tent and its evaporation at the surfaCe leads to the concentration of sal ts in tihe surface soil. Rising groundwater levels und increasing soil salinily levels generally OcCur becuuse of over-irrigat. ion. Ilowever the accumulation of sal ts in the upper part of the profile Can also occur with under irrigation where insufficient. wa ter is applicd ror downward leaching of the salts. Following a briel' exunination of water IAnagement practices on the Mellka Sadi fama together wi th th: duta on irrigation wuter supplied it Was concluded thiat over irrigation is a priury cause of soil. sal ini Ly through risig groundwater levels. The beNana areu on the Me lka SAdi State Far is illustrative situation that has developed as a result of over-ircigul.i on. This [erennial crop has a very high water requirenent And applying an irrigation efficiency of sONe 70% us is noruua] for basin irrigation it is apparent that. over Lhe year the quantilies of wuL:r unused, which ay be largely deep percolution 1losses, are very coISiderable. of Lhe In pructise Lhe average for two reusons: irrigation efriciencies have probably been lower Lhuu Lhere has ten little resLriction on and no atteIpt has been Iade Lo easure Lhe qusrnLi.i es of huler Che avai labi liLy or swaL:r appli(xl, alt.hough lusuring structures huve ben pruvided. Kenerully of the soils of the sul'licinlLy high unana irrigation without observable dutu x:eabilily Lexlures ging eflects in Lhe trniaT GL. 1.0 16 JThus in the absence of drainage the rise in the waler table has been relatively rapid and in any areas evaporation ('rom the soil surlace through capillary rise lron the groundwater has accelerated sal.ini sation of the soil. It seens likely that the cutton areaS ad jucent Lo the barana lands which hauve been ubandorned have also been affected by high water tables as a resul t of over irrigation of the bananas. The scope for over irrigution of cotton is a gooxl deal less than for bananas particularly since the cotton Crop is IIOre obviously susceptible to waterlogging. As a result the waler table problen is conuIIonly not associated with the heavy tex tured soils which haVe lower infiltration rates so that over irrigation lhas More noticeably danaging effects. Consequent.ly the incidence of salinity on Lhe heavy Lextured soi ls is less. The tenleney lor over-irrigation iS IIOst acute on the inixed textured und Iediun textured soils where infilt.ration rates are much higher. Imperneable luyers ocCur in the profile of these soils and perched water tables are sometiues found which also contribute to the salinity problem. An important cause of over-irrigation of cotton and ul tinately of an increuse in Water table height und salini ty, is Lhe irregular microtopography on many fields. As a result during irrigution the water becomes Konded in the lower spols be>ore it can puss througl1 the furrow to the lower urts of the field. lcads t.o a breakdown of the ridges with lateral This IOVeent ponding of couunonl WiLter y iand a loss of control over application rules by individual Consequently excessive applicalions of wiL ter aAre IAde unevenly distributed ucross the lield. I'urrow. hich is Based on obserVations in the lield it would appear thL u rigid schedule of irrigati on frequency is being followed. It is intended Ioisture status as observed with the use of aliger' that the timing of irrigation should be delerined by the Soil stuiplOs. Ir decision on when to irrigate. In practice this technique is pructice this intention is rarely carried Out. Irrigal. ion supervisors have been instructed in the technique ol uger suupling lor dleteruirnation of soil moisture status und L.he subsequenl little or no regard for soil noisture stalus. Tt. is sugyesLed Lhat Used and irrigution applications are lvde in a OuLine lkAnr nol with when Lwo or three Huger sanples per l'ield Would be L.o irrigute, but. irrigators need the noru in deciding feel during of the soil. Observalions liale in Llhe last Lraining in interpreling L.he indicaLed Lenerul Lerxdeicy rOr over Lhe soil survey and during other field irriyulion aL invesLigalions ave 1.hree week yOunger sages of Crop growth and inclue .he following: leiasl. in denons.ral:d soil pils dug in ields of cot.Lon ul 3 - pro>ile ul or ri:ar îi:ld cujx:iLy Lo 8 w:k ALK] thesie fields hAVe b:en icriguled u duy or Lwo luli:r. slges 2 iave depli fields of earli:r by u Iuinl'ull hu been r:CUrded which hud bH prxd Lvo cot.Lon were being irrigulel Lhe daLy al:t 13.0 of old. ruinlall of 31.0 ul. "T'he col.Lon Wis 3 - 1 l.Lys 1vecks 17 Were being irrigated not long after this rainfall which had only sinall putches of young cotton growing. The reEAinder of the field was coInpletely bare where crop establishnent had failed due to already high salinity levels. The effect of fields applying water to bare land with the profile already at field Capacity fron previous irrigation and rainfall will inevitably lead to rise in the groundwater level and accelerating salinisation of the soil. Further evidence of over-irrigation is provided frou discussions with irrigators whose nain instruction is to ensure that the field is covered. No attenpt is nade to measure quantity of water applid and the natural tendency will be to apply more Water than is necesSary. Night irrigation which is an essential part of the Amibara irrigation syste1 further conplicates control of Wat.er' upplication rates. Other possibilities for reduc ing irrigation neet to be explored, particularly the use of rainfall data for increasing the irrigation interval. Preliminary visual observations indicate that Lhere could be to distinct situations in which high infiltration rates and deep percolation losses could Ocour. excessive In the first case siltation of minor canals has resulted in delivery rates in the canal and reduced flow rates in the which iven the long furrow lengths has resul ted in increased reducl [urroW, 3.4 3.4.1 to cover the ground and consequently higher inCiltration and higher losses to deep percolation. In the second case there are canals where higher bed and bank levels has had the effect of increasing siphon heads wi Llh the resuli that the flow through the siphon has been incresed. On unlevel ields water control is adversely uffected. Investigations Are required to confir1I whether these prelimiHIy observalions are a CAuse of deep percolaLion losses. Resource Linitations Water supply Line The the Awash river. In general anple quntilies of irrigation wut.er supply lor the: Aunibaru ProjccL Areu coles from availuble for the irrigat. ion of the Lotal C:ul.ivalinl lund witer huve l«en served by the Anibara Cunal for the coLLol However' Lxeginning of Lhe 1988 coLLon seasOn. excepl. i.on tO this KenerulisaLioH In Lhual. yeur eNCept.ional ly low iArCLS. OCCUrIi ut. Lhe cotLorn river flows (Ccurrel Lhrough Ny ad June td inlo pJuting progruuIIe WAS Iuch delaye due L.o Lhe lw:k ud July l'or Lhe: pre-plianling progruuIke: , ol' walur signifi cantly r«luced boy Llhe lute plunt.ing. 18 The 1988 Wuter shortage is considered to be an exceptional event. Nornally, sufficient water is available even if a substantial anount of WLter is required or leaching purposes. llowever the full developnient of the Anilara Settlenent Project will increase the dennd for Water. Consequently during periods of Water shortage there will be nore severe problens of distribution of limited quantities. Because of serious problens of siltation in minor carhls it is a continual st.ruggle to maintain the delivery syste1 at (ull capacity. Irrigation Water is uvailable from the Awash river to support. A second crop in the period December through to April over much of the irrigated land area served by the Amibara caral. However to dat.e no advantage has been taken of this opportuni ty for increasing Crop product.ion. A IIA jor obstacle to increasing cropping inLensit.y the heuvy canal maintenance requirement particularly or de-silting operations which requires long periods of canal closures. If this obstacle can be overcone systens have to be econoni cally viable crops and cropping Cully occupied throughout the year with the single cotton crop. developed. At the noment. the Maragement are 3.4.2 Machinery and equipment An inventory of the farm is presented in "Table 7. Achinery used on the Melka Sadi state faruu and In gerieral adequate nunbers of tractors for inplements are available to the present farming systems involving bananas and cot.ton. undertake Lhe necessAry operat. ions However the target replacenent schedule for the far1n not. achiery is and implements which being adhered to and a disproportionate nunber of old Lract.ors included in Table 7. The ageing tractor rleet and are reaclhing the end of their useful li le implenents places are a heavy burden on the inintenance workshop and creates dif>iculties in achieving timely cultivation operati ons. 3.4.3 Availability of capital Funding is provided for the Mella Sadi Fann through the Midde Aish Agricul Lural Enterprise und ultinately through the Ministry of Stale Parus. Budgets are prefured in the year previously und in genernl obtuining funds for cupitul expenditure on lvajor iles re-current expenditure is udequat.ely funded. ProbleS arise of with Such As tructors, and for uIOst los of fixed problens are urtly due to the scaCity of foreign exchunge. investilent.. IEchinery "These 3.4.4. Human resources Beased on a Very briel' encouners wi Lih thk: M:lkaa Sadi Fam WOuld seen that urAgerial cauLC:0 L.y is I0t Lhe mujOr coISLruint. 19 TABLE 7: INVENIORY OF FARM MACHINERY AT MELKA SADI STATE FARM, JULY 1989 NACHINE/IMPLEMENT MAKE AND TYPE Tractors 130 HP NUMBETR JELD FIAT TURBO 130-90 DT NUMBER OPERATIONAL. 100 HP 75 HP Disc Ploughs offset Disc Harrows FIAT TURBO 130-90 FIAT 980 DT FIAT 980 Norunal IMT 5106 Model FIAT 780 NTP BELAURUS TOTAL Noral 10 21 53 -0 IMCO ALVAN BLANCH 4-Furrow 3-Purrow AMCO 4-FurrOw BANDAN (BRAZIL) 5-urrow 29 Land Levellers Ridgers Inter-row Cultivalors Planters Trailers Sub-soiler Mould Board Plough Rollig cull.i vulor wilh iuter-Ow cul LivuLion + DiLehing Mchine/ Ridger Digker RANSOME (UK) 4-5 roW RD 23 (Israel) NARIDI (Italy) VarioUS Models STANHAY JUMDO Plunters BANCOR (UK) ZIMNACIT (Yugosluvia) NARDI (Italy) M.F, Meakie Uuhriown. Vesry Luge IDUFF MF 3.6 - 4.7 u Spring Tooth Harrow (not used) EVERSNMAN 45-12 Mxdel EVERSMAN 329 Model (nvade in Italy under License) 29 7 3 2 7 I6 14 10 12 Malke Uuknown. Very 1-PurrOW 1 Make Unknow), SuvLl 2-urOW large 2-Furrow 2 LEIINAN (Lillislon) [OCIAIN 1 20 be satisfactory. The general appearance of the cotton crop in 1989 is impressive and behind the scenes the general standards of record keeping appear to failure to appreciate the need for the developnent of skills at the An important deficiency of nanagement may be its field level. The basic skills required in a goottrautur driver a an efficient irrigator may not have received the attention they deserve. Consequently unlevel fields und over-irrigation have been Iajor reasons for the rapid develop1ent problen. of the soil salinity The supply of unskilled nAnual labour is constraint for tho specific tasks. The heavy work of and field canal is usually too much de-siliting terliury, quaternary the use of nechanical diggers is presently under consideration. has becone increasingly difficult to attract suflicient. for the available labour arnd It . 6.1 labour into the area to harvest the cotton in a timely and efficient Ianner. Consequently the MAAE have purchased two mechanical cotton pickers which will be used for the first tine on the 1989 crop. Husbandry Limi tations BananaAS The salinity proble1 has becoe of such over riding iportuuice in bananas that other husbandry practices have de only IEg inal differences to production levels. On the few belter fi+lds high levels of fertiliser use have been appliel, weed control arnd sukel' managenent huve been of u high standard elc. Ilowever as soil salintiy allowed has reduced crop vigour, husbundry standards huve been to slip and lack of weed control And inadequa Le fertiliser 5.2 Use have undoubledly accelerated Lhe demise of the crop. Cotton Basic evidenced by yield levels on solue fields which equate wilh those cot ton husbandry pructices are good on the Melka Sacli lunu us oblained uder trial condi tions on the research fam. Tiun: plantingL is a najor cuuse of reduced yields. Good weul cont.rol obtained by echanical method of control-inlerr row cullivaLion at'r the pre-plant irrigatiorn has geruinatel wecds is follUwEXd Ly furtheer inter-row cultiival.ions at suituble intervals unl.i l the ot.lou height. precludes furher jASSES. Lo uAinlain conLrol of weed growth until Lhe cot. Lon foIs A closel CAnopy . Pest. control is uchievid Lhrough eriul upplicul.ions ol inswt.icide ilId is aparently highly el'lective, Sone pnal wding uLy Lhn la: reguirel 21 3.6 Fertiliser use is restricted to occasional applications of nitrogen in the form of urea. Hoiwever work at the Melka Werer IAR has demonstrated only a small responses to nitrogen in a nunter ot trials. On the other hand a long term fertiliser trial at IAR has denonstrated that there is no response to applications of phosphate and potash even after 13 years of cotton monocropping. Sone improvements could be achieved in cot.ton production by more careful operation of ridgers and planters. Unt.idy ends of the field with uneven establishnent are conuon and the occasional patch of unplanted land due to malfunctioning of the planter could be avoided. The Amibara Settlement Project This project is Comnission which is a quasi Governlent Orgnisation that. does not being operated through the Relief and Rehabilit:tiorn receive largely deperndent on foreign funding through various APparently internat. it ional a budget allocation in the normal way. is aid agencies. Thus financial resources uvailable to the uncertain and invariably inadequate to enable the project projet ur: any progress towards self sufficiency. to The Over-ride utiliSe the any available cOUNercial resources objectives of or larnd indecd and ny utLeupt Lo project has social object.ives which at the Ilodent object.ives wuler. indigenous Alaa peple who lost Iuch Were of to their EACCOIKXt.e SOMe of the seltlement. The Tully SOCiaLl LrudiLional o the lauids with the developncnt ol' the Aniburu projr:t.. The rart.iciil Srzig ioti of arable agriculture, the Cash loss and in uddition it wus an Che Afaa in the sett.lement wus a foru of conpensulion for econouny urd a huy o lile in ellort Lo can relat.e nore closely to nodern ELhiopiarn Sociely. introduce Lhe popl: that hich they to The social because of objectives of the f'ailure the failure of the projoL in project have not bn uchievel May be partly Work due Lo the difficulties in training Lhe: prductive Lers. largely lifetiIe Lo do NanAl underake rd of the tLruditional in the fields ud brking L.he habiLs oi Tluis AtiuL all the physicully onerous Lasks. lilestyle in llow:VHr Lhe absCe ol which tlhe: proper rewards for the llorLs of le Af:u and disinterest. project wAy ulso hiaV: Cunl.ribuled to Lheir Arl icjxnl in Lhe The Auilrn which Lhe lulxour. "Ihese SeLLlers SelllMul. Projcl l'au is ojal« is n olleeive individul inpul.s ure roonlul ul al. h l o h seso) IAre requiral Lo povide Llu: iujals of praluu:l.ivil.y li:vels on Lh: l'au has reeeivGs u sluure ol he surplus h Keerl.ion ol surplus iwo: lo ti. hl. Lher hus u iLl: liknave distrilulio. 22 Low productivity of the projects is due to a conbinat ion of factors of which the poor quality of the nanual labour and semi-skilled workers has already been mentioned. Neverthless perhaps the IOSt important limiting factor has been the lack of resources which has prevented optinal farming practices from being followed. The late planting of cotton and maize has been a regular occurrence due to tractor and nachinery breakdowns and the lack of noney to ensure the timely availability of supplies of seed and agrochemicals. The late planting drastically reduces yield potential and poor standards of crop husbandry subsequently results is very low yiel ds. Superinposed on this rather disnal picture are the increasing levels of soil salinity and the patchiness in crop establ ishment that is the typical synptom of soil salinity. 23 4. 4.1 FUTURE AGRICULTURAL DEVELOPMENT REQUIREMENTS Objectives and Policies The Amibara Drainage Project the Ethiopian Governaent which is being funded by a loan represents a substantial investient by l'rom the African Developnent Fund. This repaid. Thus it is inperative from the viewpoint of the National loan will eventually have to be Treasury that time. maxinun benefits are produced in the shortest possible The unless the agricultural management is geared installation of drainage in itself will not produce benefits to talke advantage of the in1proved conditions resulting frOn the drainage. The identification of the constraints to agricultural development in the situat.ion following the installation of the drainage systen and the a vital component or the Consultan ts work progrwuie over the next 18 preparation of plans for the removal of these constraints is seen as IIonths. There are well de fined divisions of responsibility in tlie Stage 1 area of the ADP. The Water Resources Developnernt AuLhori Ly, through its twO subordinate bodies the Anibara Project Control CenLre (FCC) and the ADP, the ain and secondary canals and ain has responsibility for the operation ard aintenance of drains, lor the design and installation of the drainage systen and activities. Each of the orgarisations the Stage 1 urea which include AAE, invol ved i the irrigalel for various IIOni toring Crop IAR and ASP, has production activities of responsibility for the operution and ai1kenance: of distribution canals fron tertiary level down to the (ields, for the Imaintenance of opern field drains, for the lund prepaation operations and for crop husbandry from planting to harvest.. Major land levelling organisation operations has no sui table Iachin:ry lor ure suid to be the responsibiliLy of but this undertaking such PCC Work. "The IuAJOr effort to iunprove the iiplenentation of the druinage project siould coincide with ugricul tural prouct.ive pot:nLiul nd Water lvANAgement. in the Suge 1 area. cOordirnated upprouch PAAurr to be ny single echunislt or AL the orgunisul. ion to leililal: preseul. LiK: here: dues ot. Tn oth:r words a fully is needed. liven ul Lhe local Lhe COOrdination despi Le the obvious the relutionship beLween the slate udvanges. level Curl organi sations ud .lu: PCC is not a close one. 24 The absence of tangible coordinating lints between the WRDA and the Ministry of State Parms at the top level and the slightly tenuous at the local level creates problems for the Irrigation Agronouist in fulfilling his terns of reference niost of which are heavily involved with activities at the field level. Thus whilst. the Irrigat.ion Agronomist is ostensibly working for WRDA and the ADP most of his Work will be dependent upon the cooperat.ion and participation of MAAE, IAR and the ASP. Obviously his prograuIe of work should developed together wi th these organisutions so that he receives their approval and support. In addition a clear definition of the responsibilities for funding uny field work should be clearly defined. Positive action is required to establish a coordinated approach in research and monitoring progranues. For exanple, in research IAR already has a progranne of research covering sor: aspects of ater Ianagenent and including sone leaching trials ad it lias been agreed that IAR staff will assist in Lhe operation of 1.he Pilot Drainage Trial presently being run under the auspices of PCC. Foruel be recognition is required of the need to develop a joint programne in 1990 of properly foraulated trials that. will contri bute in a practical sense to the future improvenent. of water nanngement on the state farns. In the oni toring progranmes the MAAE al reudy has un o-going soil sulinity moni toring prograuK: being undertalken by an ex-patriate soil scientist in the Ministry of Stale Farms. This WOrk Iust be integrated with the prog runnes hat ar: Lo ba: devised for the ADP trained. A Survey soil surveyors und laborat.ory is presently being undertaken by MAE technicians presently on Llhe Melka of land areas affected by salinity within the areas cropxd with cotton. Such inforuation will be extrenely uselul in the planning of priority ureas for druinage and for preparing a phusd prograie? of develop1ent. Hucn ol the previous paragraphs of this section huve been devotl to Sadi and Melka Werer State Furns to obtain precise cstiv1les early stages of the ADP. The sane cunnol be said of Lhe Setlleuent Project which is struggling along with niniwal resourees und the state farns and IAR because they have uch to Contribute in Lhe unwilling labour force. "The bASic requireent wiLh regaIYd Lo the ASP is the need to establish what is to be the policy in le future. In 1 LS present state there is no chunce of obtuining 2uny tt:Lurn t.he Very Considerable investent. required Lo install syste. the provision TT the priary of coupensation Lo tle Alua x:ople f'or lOst. objeLive of the sett.leuen. is Lo reLin as lurnds with related sorial uins then there is little prusJx*:t. lor future change. Similarly if the project. :0ul. inues Lo b: slirvexi ol graziIH I'esources of equi paernt IA iAnt.icipaled. CupiLal LheU NIS7 RARY liLtle chuang c oF WATER AND RESo. ICE 25 oCUMEN WATION 4.2. 4.2.1. A policy decision is required on whether to stick with the existing aims and objectives of the ASP in which case the high cost of drainage could never be justified ecornomically or financially, Or whether to invest the capital and provide the nanagement which could transform the project into an economically viable enterprise that could justify the inves tment in drainage. It should be pointed out that the ASP represents valuable resources of land and water which the country can ill-afford to renain largely unutilised. The re-developnent of that part of the ASP which has been allowed Over the last 5 years to revert to heavy Acacia type bush has been discussed and it has been included in the Stuge 1 area of ADP. This area is presently used by the indigenous Afaa as a grazing area and its re-develop1ent will be a loss to those people. I the chosen policy option is the full development of intensive irrigated agriculture on the ASP then clearly some irrigaled pasture and/or forage crops should be included in the rotation to be nade available Lo the Afau livestock as a form of compensation. Indeed the supply of livestock feedstuffs to the Afaa nay be a better Way of encouraging them to undertake nanual work on the arable crops t.han the present profit sharing system. Land Levelling Background No jor correetive levelling has been undertaken since th: origiul land developInent work was done on the project prior Lo pliuiting the inaugural crop. Poor land levels are inevi table however, due: Lo Sone consolidation through irrigation naking secondury levelling necesSary . Since developuuent six or se:ven cotton crons have been praiuc«d that SO opporLuni Ly even ir the levellirng work was well done there has beun iunple operation. SOIne tines l'or the disturbance of land levels since t.hat initial An imporLant factor creuling nicrotoxgraph ic operaLion, uicrot.opographic particularly with variatio has bee:n di sc ploughing. iuprop:r wAch i nery olie Lructors drivers were proxerly traied in the early days o! i: irrigation project. but. Wi Ch A COuplele luc:k of incenLives ckly Jost. any pride they hud in a job well done und TurOWS h1 louridsS and unLidy finishing tCuIe cOIMION Plz2** The si l.unl.iorn has nol. been inprovxl in recent yeaurs by the ecessary (uploymen. unt.rained nnd have deteriorut.el despiL: shoddy ploughuunsh i p wilh use: of Ever'suuatn land levelleI's. nskilled Lruclor riverS. Consejuent.ly lant livels Che elTorts to correel. Lh: el'lcts ol Ilosevr requires retàch iTc: Ls desiged for uninor laxd levelling or sa oLhing ul resul Ls. Ccarelul N[K0encod o:rulur lo u:hieve salislir:Lory 20 Unlevel fields have nany adverse and costly effecls, particularly in fields where the length of run of the furrowS Conunonly exceeds 200 l. Some of these ef fects are briefly outlined below: i Depressions in the field cause a ponding of water which can, and often does, lead to u breakdown of furrows, the laterul Movement. of water acroSs furrows and a waterlogged patch of Growth of crop. seedl ing stage onwards resulting in lowered yield levels. the crop is severely retarded from tlhe ii. The ponding of Water eliminates possibility for control over the quantities of water applied in depressions any either t.o individual furrows or to the field as a whole. If the field is to be covered with water the application rate is invariably excessive where the land is not level. Irrigators are instructed to ensure that water reaches all parts inevi table in carrying out this instruct.ion results in of the field and the ponding of Water that is very low field irrigat.ion efficiencies. iii. The loW field application efliciencies on unlevel fields ure Caused by excCssive losses of Water to deep prColation percolation losses to direct evaporation levels both at the surface und down the prolile. contribute Lo increusing soil f'ron the ponded areAs. The deep salini t.y iv. The unlevel ficlds have been observed Lo iCreuse Lhe laxur I'equi reent. TWO or three len Iay be requird Lo ensure Lhal CONiplete COver of the field with irrigulion Nater is achieved. The äddi tional field bunds to prevent laleral IINOvelnernt of waLer aK Lo labour is necessary to f'orm in foru and naintain the ridges. V. Over Lime the low field application eficiencies inevi tably lead to a rise in the groundwater any forn of drainage, which evaporation wat.er will rise to the sur face by capillary suction. will eventunl ly reuch a level at level which if uchecked by The of this waler at the soiI surfu:e resul ts in ever increasing concentration of salts in the uppr arl. of the profile with increasingly observable HdverSe efTt.s crop perforiance, viable to continue cropping the lsnd. Lo the point. ul which it. b:coues no loiger vi. The Irnitinl signs of sul inity us deCNstralaxd by he lailure O esLablislh the CoLLon crop are couiIonly elulal l.o arS o! SIIAl] depressions in thu lut surluce. otservat.ion it. IAy b: Conclwlxl Lhal. Lhe lach or Based on Lis Jevellirng hHLS COnt.ribuled Lo more rupid level l'ields salinisn.ion of lhe Soil Lhan WOuld huve COndilions in which wutLer (CArelully con.rollxd. appl iat.ion rales :url on COuld la 27 4.2.2 Extent of land levelling requirements It is apparent that nany fields in the Melka Sadi cotton lands i elsewhere in the cotton lands of the Stage l developnent are ure unlevel a result. and that irrigation efficiencies are drasticaily retuced as Arandom study of this was carried cut during th: Maste:r Drainage Plan Study \1. Nevertheless no detailal studies haSe so far been undertaken to establish the requirements for jor corrective land levelling. Without such stulies one cui only estinua te the size and scope of future land levell ing requiretants in the Stage 1 area of ADP or elsehere o the MAE fans. Consequently priority should be given to the studies yuirt so 4.2.3 that once the size of the problens has been determind plan can be prepared on ho to tackle the problea. Option for land levelling Ction 4.3 The option for undertak ing the land levell ing wort hs decided. The equip1uernt will be procurxd throut1 ADP 1 ! tuuaixi OVer to PCC who will carry out the lund levelling on bhcalr of the benefitting entities, A charge to cover costs will te zat'. Land Reclamation The nain reguirenenL foc the reclution of akudoni ares ii Lite Sluge 1 area of ADP is for the reuovul of he uuaululd alL the profile. The installation of un elfctive drainge ysten required before the leaching prcess for the OVal of Uese salls cain uuke place. Leaching und the reuoVal of sults in the duinge aler is the unly effective action that cun leud to the full rulun1tia1 of prs ntly alundoned areaS. However every ellort should b kule to miniaise the continuing increase in salinity which is thing plu in luts already abarndoned and in lads hhich will tee abuunlotxl i U: est year or twO. igO1ng uCcWIulation of salts at thet soil surluv riscs winy in LOlerunt vegetat.ion has not y:t bac: (:stablishuxl. MAcle devoid uf vegetation by cultivution ual her: ln Ch aNAS Waler Surluce by capilary hcLion X eya| Nrut icHI Iu th r: ) uibles ure ul u leyel fu which salihe Su dhuler xDV CONCAnlrat.ion leads to increusig concentrutions of sulLs. in Lhe Jut ol Lhe profile th leaching (:SCuluL: rupidly. reyuiruK:al.5 in te*LS o LiuN: wal qLuli's Sir Wiliun Ibslcrr)W 1985, Volw: 8. 23 Tn order to halt this Surface every effort needs to be made to establish salt process of salt accumulation at the bare soil vetetation both on fields already abandoned and on fields that tolerant are to newly abandoned. The local star grass, tolerance to saline conditions, is easily which propagated appears vegetatively have good and has good nutritive value for livestock, SeeniS Worth investigation for this purpose. There will be no problems with the renoval of star grass in conditions in which the soil moisture condition is controllable for much of the year. The vegetation will assist the reclanation proceSs in the following ways: it will use sone water frou the groundwater table und nost. of the rainfall and will therefore halt the rise, and ny even resul t in SOMe reduction, of the level of the goundwater table. it will maintain the physical condition of the soil and so greatly improve infiltration rates and ultinately the rale of leaching. there is general.ly some uptake ol salts from the soil by sal l. tolerant plants which in itself may assist in the reduction of soil. salinity levels. As the method installation of the drainage system proceesds u practical need for Obviously of leaching will have to be developed whicl1 uuy inclul: a Lrial work should be instigal.ed to identify crops years. thal. the planting of sult tolerunt crops in the early and of 3 LulTill this need, but no work can be done on leuching e:Lhals requiremernts until the drainage system is inslalled. Plunting Salt tolerant crops should be di scussed during the first lRA jOr 4.4 Coordination meeting in ebruary 1990. Lmprovement. of Water Management Practices The deficiencies and limi tations of present. wiater ikAnageGnt Practices have fields will Ilanagenent. 8reatly enhance the been discussed earlier. Wi th cot.ton the degree uch o control iprovcd. over quntil.les l possibilities for iuproved kataer The prepxration of level taclvantuge Wat.er appliecd to the tields will be In order Lo Lake Trrigat.ion schedul ing is of this iore DreciSe conLrol a KOre prugul. ic pprOh At. to b: requirCd. firuly fixed. Dresent tine Lhe irri taLion schedules teing lollowexd Very heuvy f'alls OCCur. liittl: ucCOunt is uaken of the ruinlall unleSs aj C:rop are sclheduling should be de:eruin:d by u cOnbinal.ion o not reflectLd in lower uppl iantion rales. calculaLion nd "The lOWer waer reguircuents of Lhe: IrrigaLion yourIgr" OUservution which uight. inclde. ..ard usSup. iorIs ou soil lNoigLue charucLerisili(S; Lhe Lheoret.icul (alculul.jon of consuupl.ion use pplixl 'olins! (deeplhs, clfe:t.ive ruinlull elC. 29) b. the observed soil moisture status of samples obtained wi th the use of an auger, areaS. or by the use of gypsun blocks on C. the observed temperatures. state of the crop during period of Selected maximIH At present. the use of gypsun blocks for determining soil moisture status is being evaluated by IAR and the resul ts are encouraging. Laboratory analysis tests at IAR. is also possible for these d. factors limiting production Such as weed cont.rol considered. (See Appendix 1). should b Quantities of Water applied can be accurately aSsesSed frciu calculation involving the nunber and sizes of syphons usel, approximate head and the time which they allowed to flo. HOKever, a system of measurenent of Water applicution Iates cannot be introduced in the present cilcunstances for two in1portant Ireasns: the unlevel fields which have already been referred to and Secotdly Lhe general luck of expertise Nnorgst mAnAgenenl, the field Supervisors and the field irrigators. Thus, having levelld tùe Tlelds to permit. nore precise Wute' ContIOl, the next step kould be Addition to tO provide sui table training for all waLer nunAgement personnel. Lhe field irrigators. training soe forn of incentive would be quirei In for The lutter are presently .xid the S 2L5 4.5 4.5.1 unskilled labour" on the state farns and not. surprisingly they constantly changing. In order to train nd retain COmx tent ud Capable lield irrigatOrs the work should be clussil'id at leust Sll-slilled and should be rewarded acoordingly. IniproveIent of Land Preparation and Crop Husbandry Practices Bananag The decline of despite eusonably the sutisfacLory buLaNa crop sLandurds in Melku of Sudi crop has luslxuxiry. bun l1zunli: The SC questions that Hust bxe CuCd witth the Leueuu croP e: i) ii) n sutisfuctory byuBm viel ds sustiuin iu Uhe Kiven good druinge? log Whal elct would a chaIge Lo iOUK: l'om ol' oational roppi! have lnsutlicient. y on lxuaS yields ud tie sustuimbility of prauLion? Line WAH AVailabl: in t.his 'irst. shorl isil t) obtiin siLliniLy. vinil., i any ASG larHely uuAshed by Lhee 0ver-iding inj x»ta v: LheHe questiony will x: ureshd durins h '\ 30) 4,5.2 Cotton The problen with land in the techniques eniployed but rather in the way in which they preparation practices in cotton does not carried out. in order not to cause neven land surfaces tractors and and implenents is vital Correct operation of lie are effects on irrigation efficiencies. drivers is an essential first step tOwards correcting unconventional The proper training of tractor subsequent adverse practices but in addition recognised skills and for a job well done whilst at. the proper rewards must be given for introducing disciplinarry procedures to pull those drivers into line Same time who do not perform satisfactorily. Alternative systeis of land cultivation also be investigation. Tor example the use of chisel ploughs may wOuld provide 1Worth a depth of tilth similar to that of the disc plough for easy breakdown by disc harrowing whilst at the sane time creating mininal disturbance of lánd surface levels. appropriate in so far as the actual speed of the soil cultivation is The chisel plough inay also be not an essential part of weed control and it higher worlk rate than the disc pl.ough for the sane tractor power. will give sonewhat Tine of planting is crit.ical eleuent which potential undertalken in Africa. yield of cotton in the Middle Awash and The optimun period in by IAR, is froIn early May through to Inid-June. Anibara, as denonstrated indeed elsewhere determines the by trials decline rapidly Yields proportional to the with later planting, the rate of decline Although the importance of time of nunber of days outside the optimum period. being nzanagement circumstances planting of at least a part of the crop. usually planting is fully appreciatEd by prevail which result in late responsible for In 1988 lack of water for the critiCal delayed planting but such a deficiency pre-plant irrigation Corrected. In significant Dart 1989 of the delayed crop on planting the two WilS State less Parms Serious INas plnted but Cannot IWAS be after diffiCulties which can be corrected by improving Lhe reliabilit:y mid-June. In this year delays Were due t.o operat.ional the far1n lächinery und Ianagement effici ency. of Fertiliser use orn the State Purus ut Melka Sadi nd Me l ka Werer is restricted Lo the uppl ication of urea us u top dressing at the rate of urowd 100 kg per hecture (45 kg N) Lo coll.on crops which yellowing, slow growing nd lucking in vigour. In sone lields where the Cot.ton growth is not vigorous it is dificul t to distinguish Lelween the effects of soil Sulinity nd nutrient deficiencies. It. IAy therefore be uselul to inves tigute cotton yield LOSPOnse, Lo uoplications of nitrogen, phosphaLe il potush on these ureus where Lhe C:olLon is less vigorous which is usually ussociuted With Lhe: lighter Lextured suils. Previous lertiliser work ul IAR has CArried out un vertisol soils. 31 Pest control anolications of operations are largely restricted spot Spraying being carried out insecticide based on a scouting system with scae to aerial appropriate. undertaken to Insufficient express an opinion observations on the and eflectiveness investigations have been using knapsack sprays here control prograune. mid-July However one observation is worth nentioning. In of the pest. which it later transpired was due to the careless use of insecticide large numbers of dead fish were observed in the ain drain either frou the aerial spraying equipuent in the drain. Pesticide use shÏuld be kept der application or through washing manual Continual. review and every effort should be made to prevent damaging 4.6 environnental pollution outside the cotton fields. Agronomic Trial Programme Much Melka Werer IAR. closer links should be forged between the State Faras and the WOrk plan (proposed Meetings were held in May 1989 when an outline lrrigation, pre-irrigation of cotton and wheat, iunl a stuly uf crop Water requirement.s. Represenlatives of State FarnS iere present at the ieeting and it. is iuortant that the latter should have solie S4y ln determining the IAR Drograunie of work ad off-stalio1 Lriuls. batarna production has been in steady decline at Melka Sadi for Miy years and yet little research effort has been nde to investigat: PoSsible approaches to halting this decline, As u rusult the latu by IAR) for trials to evalunted surface CIop is almost indication as Lo whether sustainable production is 0ssible wiUi or at the point or extinction ad Lhere is litLl wit.hout draimage. With a production cycle of at leist 5 or 6 yrs 1t talkes years to obtain reulls fro any uuunte field exr ieits. ne enVironunental condi tions of the arc it is likely that he key developing sus tuiable banuna prxluction lies in tlle developent. of u suilable efficient drainage syst.em is rotaliol, installed. asswning of Course Other probles that will Lat TIeed LO be tackled after drainnge inc:lude: ikthot o surtae irrigation to be used, Trequency, fertiliser use, etc. irrigation waler application rates Wk Leaching installat.i ion to determine the rules trials will nee to : condueted lollowiny dringe Teducvd by known quuntitiCs of kLLer' (on Che Various soil Lyja:N nt. nhich salinily lev:ls can l Cor VIariousS Col.lon areUS. (Condiions of saliuity covrig lxoth also ta: the lxuwai tl sad: to Mrl 4 or Lle soil ad Tn thiS respe:t. referetice shuuld ProgrMK l'or 1989-1990.\0 Groudwaler MoniLoriug \I Soil arnd (iroudwuter Moni Luring Progr r'u: 1989 - 1990, MMP IAHul 1980, 3? mhe results of these trialS WIII be used as the basis for leaching progranne for the Stage 1 area and for restoring the to a condition in which the traditional plannind soil a can be planted. Alternative salt tolerant crops need to be tried crops of bananas and cotton and tegted in 1990 and 1991 so that the ost promising are available for the reclanation process as soon as the drainage system becomes operat.i Lional Preparations for the leaching trials can begin with Fhe identification of suitable sites representative of the range of soil conditions within the Stage 1 drainage area. Infiltration tests night usefully be carried out at these sites. Agrononic trial progranmes for cotton should encompass cultivation trials, fertiliser trials, and water managenent trials. Subsoiling for cotton will only be important where there is u plough pan. The cultivation trials, which are seen as low priority because of the rarity of soils with a plough pan, are required to detemine the effects of deep cultivation and sub-soiling on cotton yields. Fertiliser trials are also of low priority but could provide useful infor1nation if carried out on fields of known low productirity. Deep cultivation may be worth investigation to see what advatilages to be gained from reducing the salt concent.ration in he top soil. Naler nighest Ianagenent trials and priority and the requirements are discuss-d in nore devul investigations are s1en as huuving the in Section 5. Also as a hatter of soIEe urgency field invesLigations should be: Tidertaken to investitate the possibilities of planting cottor: ado the sides of proveIer1t in cotton establishuent could ridges rather than along the tops of ridges. S: be anticimlel by plntiIg 4.7 along the sides. Training Soue this talning requireu1ents drivers. report including Practical iIstruction is have alresdy been rel'errd to walier in the water nageuIent required persOruiel uxd courses should b coupletion of Lhe lund druiwg. ud Lractor levelling organised and Coupletid Hork wlhich probably best before the follows the installutiou of the Senior Water Lraining on the liIet.hals of Watl IlkArhagement personnel ulso reuire KOr adv.ncex! practicul USpects of opt. imal alloalion of waLer, in Ler control und in supeervision of ivld irrigalors. irrigation. Piarl.icular ¬1iphas is should tae pluced on kaler control during night Training will b: equirxl iand PCC. levelling work which is Drobkibly b:sl. undertuking t h: survy ADP t I for the teuns orguisd hrough lh: 33 ,8 Amibara Settlement Project Planning Section 3.6 of this report highlighted the problems associated with the Amibara Settlenent Project at present and the failure in real terns particular the view is given that the social objectives have of both the social and the conuercial objectives. In not been achieved because of the failure in productive terns. During the course of the preparation of the Master Drainage Plan for Melka Sadi and Amibara Areas \1, the Relief and Rehabilitution Conmission proposed changes to land use and settler land allocation within the Amibara Settlement Project although at the time this did not. represent Goverrnent Policy. The infrastructure and cropping attern was to be re-organised to acconmodate extra families caused by the proposed acceleration of family settlement arnd purtly to nake the area self sufficient in food and fuel. uSe ratios Were as follows: The proposed land % of Area Cotton Maize. Vegetables. Pasture (for the Dairy Enterprise) Forestry. 4 14 5 53 14 Ln8 the report review varying land use plans were also evaluated. These were : a) A reduction in the area of the dairy enterprise b) An alt.ernative cropping pattern with 100% cotton c) alternative cropping nattern of 50% cotton, 257 Ialze and 25% pasture. The primary objective should now be to decide which of the alternative plans will be adopLed by Relief and Rehubilitation wilsOn, which will be socia]ly and cownercially viable and which A COiprehensive uly exploit the land and water resources at iLs dispOSt. should planning Or decisiun aking exercise be uidertaken under the auspices of RRO. The first. task of the Afaa would be to hold discussions with the role in the future project.. present project to detemine Lheir representatives people engaged in the De aken into ccount when t'oulat ing developent. plus. Agreeents rCached with tihe Afua will The the the initial. step Crop(s) Lo tK growI. This will be in Lhe pluming process will b: to lially select. lollowed by t.he decision iype of Or faruing system, whether h large IK:chunised sLat: Lhe IOsL tuViailable Anal labour. operat. i on or u settlement project akig I Sir Willialn IlulcrOw & ParrtnerS, July, 1985 34 plans infrastructure covering could then be prepared for the developIent of the physical field lay-outs and other on-far1n infrastructure. the irrigation and drainage systens, the Given the selected crops and the chosen farming system, the requirements for on-farm equipment, buildings and farn machinery would be determiined and cost estimates prepared. Crop budgets kould be prepared. Human resourCes required Would be estimated including nanage rial expertise and skilled and taken of exist.ing resources on the project. manual labour needs. Full account must be A detailed phased developnent progranne should be prepared with a corresponding schedlule of capital investment requirenents. A casi1 flow analysis could then be carried out to provide the controlling agency with sound estinates of the financial resources that have to be made available to the project, Economic should be carried out since they will be of and financial analyses of the proposed project development particular importance if funding is to be sought from outside sources i.e the international banks or aid agencies. 35 5. 5.1 5.1.1 PROPOSALS AND REOOMMENDATIONS - ACTION PLAN FOR 1990 Project Monitoring Improvements and Innovations Soil sa].inity monitoring This aspect of inonitoring although of critical inuotaice in Lhe Amibara Project Area five years prior to 1989 has been und the alnost only conpletely significant neglected dala available in the Crom this period is from the pilot drainage Lrial. The laller is of only limited value in understanding the broader scene. has seen a flurry of activi ly in soil investigations. survey lhas provided soue benchuArk data over soe: 1400 soil Scientist [rom Lhe Ministry of Slate Parus is SAid Lo lave taken niore than 300 soil sanples on the Melka Sadi State Parn. Obviously the data gathered (rom these twO surveys should be xoled for mutual benefit. Similarly the data held by the IAR should be freely exchanged with the project. Al1.bough the results of past surveys provide gool inloruaLion and are useful baseline data, future soil salinity moni Loring ust have à Ore specific focus arxl be related to prec:isely d:fined c:oditio)s if it is to lead to a better understuding of the build-up in soil Ilowever 1989 The ADP soil hectares salini ty ratural vegetation. Thé: mornitoring should consist. of Measurenents of the electrical conduct.ivity of the soil extract. solutiol, 1:2 by voluie, and if present. easurenents deonsLrale thut sodiun is a problenn in soMe areas Lhen sodi un levels should also be noni Lored. Souue proposals for the priority areas in which the moni loring of Soil salinity should be Cocussed are broadly vutlined below: COmparisons of salinity levels of soils wi thin fields frou saline patches where cotton Ihas nol germinated and frou adjacent healthy cotton. This situati on occurs on lands within the Stage 1 drainage area on both Lhe Melka Werer nd N:lka levels and its errect. on the growlh of crops al Sadi State Farus. Moni toring of selected x designed to cover Loth the pre and post. drainage silualions acting as a measure of the effectiveness of leaching following the installation of drainage in reducing soil salinily levels. COlli[arisons of sulinity levels in the soils of Lhe ialkndonxl fields should banana lurids 1aelds Wilhh a nuturu) grLSs COVer, ud riclds wil.h nalural bush including lields coupleLely devuid of veg:Lalion, regeneration and ull grusS COver. This soil onil.oring would also take into ucCouril Lhe deptl1 to growdwiaLer. d:Lemie Lhe Le of "The ELjOr objecLives I'egeneralion or Lhis nonilorig HOuld br: buscline dula represeuling Lhe pr-draiuge situaL]On. Lhe Lhree se Ls ol CoIdit.ions u Lo rovid: COTrelation or soil sulihity leVels wd collO yelds. Lh: yield dalia lor th: J*ASL 5 yeurs I'ields lwoull l: SelecLed COVer f'or soil sulinity IOLi Lorig ud Llese rields lvould I'ange of proxluction levels - hig1, Juw. 36 These selected fields would also be exanined to table depths and salinity levels, soil textures in the deteinine water to maximum rooting depth, and water application efficiencies. The monitorig of soil salinity levels should be concentrated on the upper part of the profile. Sampling below the rout zonc of the profi le cotton should only be carried out if it is clearly of importance 5.1.2 5.1.3 for example in the case of high wat.er tables where the grounnlwater is saline. Aerial photography The sinplest mearns of nonitoring the cotton areas affected by soil salinity would be with the use of aerial photogruphy. The lonth of August or early Septenmber is probably the most appropriate tilie. A Serious effort should be ade to /nvestigute the possiblities for taking photographs On a regular busis, probably annually, Ieasurable changes appear to be talking place from yeur to Jear. Perhaps this could be arranged using the planes used for pestici£e applications or possibly through the niliary. IL is understand Chat MSED now intend to organise the taking oC regular aeria] photographs. Monitoring water quality The present sanples taken nonitoring of water quality is restricLed to ickly outlet into the river. Future sampling should ba: exarxdi und lncreased to cover the drain water quality uCrOss lhe Stage 1 ül'L. Groundwater has been shOWn to be of highly variable quality cross Lne Stage 1 area and it would be of in terest to know whether Lhese differrence were reflected in the drainage water. at the headworks, the iain drain uxt at Lhe druin Siltation inforation in the canals of the project is a serious problet. ioni Loring had couuenced in July 1989 and slould k: ContiIued. availuble on silt. louds is very liuital but 5.1,4 Objec.ives of such nonitoing would be to identily the need for iore Careful water Ilmanagenient to reduce the rale of siltution and/or the need Cor udditional silt traps. Monitoring crop production levels The SOlk: "The A IIOre Droduct.ion systewatic approacch is requiral in the revondins of Tield Tncluding dnte of bunLing ad uunke: iunl dLte:s o irigiLiois daua karlicularly for col.Lon. OLher levuit. dalia should also be LiSed AS u Anugen. tOOl. Iu 1989 n cosiderable nul included. This dl:la shOuld be crelul ly ssessl iUN r planted to coLLon which wiu) proxe iuvesL.igiation ol pevious o 'ields yield duta would hHaVe be:n ukauloncd. Tusled Lhese liuh have L ulLivaled und the JMalchy s Labl islua l. of Uh: cotlon Iis m. liarga uris or e soil huIve w:ern irrigalel which us Srvxl :ie groudwaater levels ud resul Lal in it Xerting ilGR" Ti salinily of Lle 5oil surle. 37 Monitoring of crop production levels will also provide buseline data 5.2 for the IIeasureients of benefits arising Irom the installation the drainage systen. Definition of Size and Scope of Land Levelling Requiremnents of During the peri od following the renoval of the cotton stalks of he 1989 cot.t.on crop when the first land prepuration operations ILTe taking place, detailed topographic surveys slhould be carried out. to provide a nOre uccurate assessnent of the quantities o> soil that Tave to be moved in tlhe land levelling process. Tlhese surveys shoull COVCr a range of cond i tions and slhould inclule boLh cot. Lon aLd bx¯laa areas. The latter ure ofr lesser iuportance becuuse Currow irrigation LIsed only in the early sages of banana irrigat.ion before changi ng is L.o the basin metlhOd. 5.3 Water Manageinent Observations and Measurements There arc sonie obvious indications that water use efficincy in the ZOne of the crops are a ILjOr cuuse or the rising groundwuter level. The ost importunt factor responsible for low field appliculioi efficiencios is Lhe variaLions in microtopography but. Lhere ure nuilx:r or 1iuitat.ions due Lu poor water lvanEgenent pructices whic1 are so lar ill-defined. Cield is at low level and that percolation losses below Che root In oder to define the water nAnagenenL limitulions on rield upplicution efrricicncies, investigations pructicul operation of the systens of Hater nllocalion are required into the irrigation present field irrigation practices, although preliminary work scheduling. Observations need to be carried out into already been done on this before.\1 Measureents of actuul has Waler Use should be nade so that accurate estimaLes ol existing vater efficiencies VIsit of the Consul Lants Water Managenent. Egineer early in 1990. can be provided. This will be reviewed during the The Tew fields y externt up t.o 300 m, Slopes are very flut. TWrroW lengt.h of run in NOst fields is ut leAst 200 in and in there is a need Lo SOIT Conditions and slorx:s tiven these long lurrow lengths. investigate field appl ication erlicieneies unkr Various \I A Ikiadiur, IAR. 1989 38 5.4 Observation on Groundwater Fluctuation The observation well data which has five Or six years do not reflect in been gathered during the last predicted rise in the water table. It Kould te useful to delerain many cases the expected or whether the observation sell readings taken kithin the Stge hater I drainage area are a true reflection of the actual depths to table in surrounding areas. For this purpose the instal lation of a number of piezometer or auger holes around each selected observation. well is proposed and this should be carried out at the rliest opportunity provided that a budget allocation can te Aad0e to do this. These piezometers will not only serve as a chck on the observation wells but will also given a luuch bet ter °dérstarding of the rluctuations in wuter table levels hich ccording to observation wells nAy reach us much as 2-3 m. 5.5 5.5.1 Applied Research Leaching and land reclamation In order to undertuke leaching und land reclanat ion t rials essential to have a drainage system that will rOve it is d1ainage water. There ure no suitable new sites lor Sueh triuls until the drainage syslem has been installed. liokever in the Ileantine the naximum anount. of infomwution should be extructexi frcaa the on-going Pilot Drainage Trial on the Melka Sudi State Farm. The initial step on the Pilot Drainage Tril should Le Lo udertah ia detailed analysis of all existing data that has been gathernd oter the t.hree yeur li fe of the trial. Based on a cursory eniation o> soie of the data it is annarent. that there re ny defiviencies and solme records are of doubtful value. In ddition there urN my Weaknesses in the experiental techniques eaployerd. Nevertheless, liay be possible to salVage sone thing froa the uvaiLable dtü elen the saline if only broad trends. During the early art of 1990 a couplete review of the Plot Urainagc object.ives for the future should be cleurly detin. Trial activities Lo date should b: uxler.den ant on preSent soil salinity levels d on the salinity of the dra hge water should Le obtuinxd. location for leaching urd lund re:luuLion trials. T proIS site is plunted CChed on who will c'ry oul winteuAIK: lo Lhe aistit duS lt WITin exisLing Pilot Druiuug: Ar on lields prrvinsly to li°anRUs but now ututndoal. Ciuals in this of he Lrials. 39 Correct experimental procedures in the Pi lot Drainage trial which could be followed for the 1990 These procedures will include: cotton crop should be the method Lo be prepared. for used 5.5.2 calculating application rates (including the leaching requirenenL.) and irrigation frequencies; the measurenent of the quantities of water applied to each plot and the quantities of water drained; the cleur definition of plots (net and gross areas); the crop husbandry pract.ices to be rollowed; the data to be recorded. To date these are not results which curn be upplied to the ain crop. Siuilarly ror the banana area of the Pilot Drainage "Trial experinentul procedures should be introduced which will ernable IlIeaningful results to be obtained. Bananas From the mid-1970's there has been a steady decline in benana yields and there has been a regular abandorunent of land previously cropped with bananas. The point has almost been reached at which the decision has to be lade to close doWI the banana operation. Unfortunately banana research has been much neglected in the ps L and little attempt has been made to investigate the Causes of deolining production levels. The assupt.i on seems to have becn that soil salinity was wholly responsible for declining yields and thal the effects were irreversible and uncontrollable. This assunpti01 should that have been under Bananas arre known be tested by planting a series of observation plots on lands a b ush fallo Tor sone yCAl'S. debiliLating diseases including various wilts, nenatodes ete and to be suscep tible to a range of soil orne have a Cropping high nutrient are WOrth requirement . environinen ts. The Melka Sadi State Parn provides conditions which investigation even in the ost favourable Thus the advantages of ro tational are lar from ideal for the banana crop and to th is must be added the salinity problen1. The combination of an unfavourable cliate wilh saline SOils suggests a need lor rotational cropping if favourable Conditions are to be maintained. EOllowing the installation of an effective drainage systelli long banaha rotational trial should be established to cxn ine Lhe elfects of Various cropping sequences on the sustainubiliLy of Ounana production. Rotational break crops would incluwe asture, reen tILanure crops, winler Seasons. and several ainual crops, in both suuiet 40 5.5.3 Cotton The basic land preparation operations presently undertalken for the cot ton crop Seem sufficient to be perfectly adequate providing good ieed control and depth of tilth on which ridges of a satisfactory size can be prepured. As far as can be ascertaincd t.here are few arcas where pan formation has reached the degree of copaction iupeded. at which rooL development and waler percolation are Ilowever a trial to investigate the erlects of sub-soiling in layer) is considered to be worthwhile. a field in which therc is a definite plough an (or inpereable becouIe Imore extensive as the years pass arnd the free novenent The an problen1 is likely to ialer through the profile to facilitate systenutic leaching of salts of is lot important.. nin problen with land preparation at the present time is dis ploughs Lhal The presently land surluces are frequently disturbed by Lhe operated. Surfuce disturbance is caused by the furrows of AS pluughs und poor finishing resul ting in unlevel fields and disc wuter distribution difficulties. It is suggested that a chisel plough would disturb the land surface nuch less Lhan the disc plough Jeaving no furrow. A suitable chisel plough carn cultivate greater depth than Lhe disc plough and at suit.able type of chisel plough relatively greater to even Speed. It is reconunended that. a should be introduced and identify suitable nodels and to obtain prices. tested. Investigations are proceeding to The field observations nude dur ing July 1989 Suggest thal Lhe the interval is frequency of irrigation is generally too high (i.e. HOwever', Loo short ) and that little account iis taken of rainlall. Over irrigation low demand periods (April and May) ind under lrrigation during the during reported. \1. In order to develop rest of the growing season hus a lethod of rule also of thurnb been trials should be uidertken to assesSment of irrigation Supplement those lnvestigale the effects of irrigation need, frequency on yield levels Lo already carried out at IAR. 5.5.4 Miscellaneous trials Lne terns of reference refer to the investigation of the p)Ssibility of the introduction of a second crop (i.e. double cropping) into Uie linilat.ions of T'arming system of the State FurIS. HOwever the the lorg red or cural liANagenent and IIaintenance nd machinery, the lack of any experience eriad requi ialLerrat.ive crops all SuggesL thal in the Nevertheless short a Lern double cropping wilh should lgin is 1ot I'ealistic pOSsibi lity. in which Lhe range of trial progrusIR: potential crops ure eunincd wi th a view the long Leu future. These alternat.ive crops iAy ulso hüave rol OSS1ble break crops in the buriana rolintion iatl/or iAS CTopS lo : grOwn Ls art. of the reclwwntion process. \1 G.1lal Jer, M:lkwu Rgi ETI/82/014 Field Doc:WlN:til No, S, August 1987 41 SoaK: applied research should als0 be undertaken to investigate ways of iuproving the This WOuld involve trials to test the adaptation of incone levels generated on the Amibara Settlenent Project. Jotent.ial crops to Amibara condition and assess their productive potent ials, Sone crops ulrcudy grown in Amibara village have potential and these include sugar cane, papaya and citrIS. The developncnt of sugar 'cottuge industry' has possibilities. cane for the prouction of jaggery $.5.5 Implementation of a crop trisl progranne There is an when formulating proposals for an applied research prograne for a important need co-ordinated approach in which all interested parties are involved. The Melka Werer IAR has obviously t.he key role in the the State Farn Ianagers inplementation of an prograi1uie but the MAAE and and tlhe Amibeura applied research SelLtleinent Project managers should be involved in the definit.ion of priorit.ies. Before any all previous agronomic studies proposals are foriulated a review sBhould be undertaken of t.hat carried out at Nelka Werer so full use is Inde of all existing infornation. Such review Iy uSSist. in the identilication of the Ore promising lines of investigation. A COIIUni t tee includ ing all interested parties should be constiLutod for the of defining the 1990-91 prograae of iappliel Iesearch. IAR staff would have the purposes leading role but oul1l be expected to liaise closely wi th essential if ADP Consul tants and As off-station trials are the lull range of local personiel. conli tions the Sage I area are to be investigated the full co-operat ion of in "MAAE, assured. Funds will have to be made available for Lhe State Farn Management and the ASP Nanagenent must be: the applied cesearch existing budgets are unlikely to be able to cover additional needs. ADP uuthorities An be required frou the Lo initiative nvay for resea'ch investigate purposes. the allocation of additional funds 12 6 6.1. PRELIMINARY REVIEW OF THE IRRIGATION AGRONOMY REPORT BY OTHER ORGANISATION Distribution of the Report and Objectives Before finalisation of this report it was considered essential the views of the organisations directly involved in implementation of proposals should be considered. This is particularly so because of the nunber of different organisations that the involved and the desire to approach to solving the problems develop a of cOordinated and integrated crop production, Ra ter management, monitoring and applied research associated with this ina jor undertalking. following organisations for their consideration before production of the final draft report. a) Institute of Agricultural Research b) Project Control Centre c) Ministry of State Farns Prelininary comnents were received from the first two organisations Accordingly the preliminary draft report was sent inforually to the and their contribution in the is gratefully acknowledged. Because of the urgency in preparing the preparation of the final draft report Tinal Draft Report before the project coordinntion nieet.ing in February 1990 it was felt that the contribut.ion by the Ministry of State Far1ns could use fully be discussed at that time and all points arising could be used to fornulate an agronomic action plan for 1990. Where possible Lhe contributions given by the two aforenentioned organi sations have been incorporated into the report, but for the record they are included as Appendices 1 and 2 hereof. 43 APPENDIX 1 CONSULTANCY SCRVICES AGRMEDNT FOR SUPDRVIS IOT OF CONSTR¯CTION - ADPI by Sir M. ac Donald & Pan tmerS comments by A Kuzniqg Mellkawerer Research Center. I woula like to make tha following comnents an 11P reports l. Irrigatiom Agronomy Report I agrea with the author on the factors limiting crop producti on levels, particularly on the over irrigation and the low application efficiency. But mder present canditi ons. it will take a long time before the efficiency can be significantly improved. As the fixed irrigation intervals boing followad ,the irrigatian scheduling BuggeBted on the page 28 nay improve water management praotices. However, in addition to the scheduling techniques rocommended by tho author, I would suggest to use the ypsm blocks for ovaluatian of tho söil moisture status, ObviouBley it will not be possible to apply this me thod for a11 the farm. nits, But some areas could be solectod for such scheduling method. At pr0sent the trials are being conducted at Melka Worer Center where irrigation schedul ing is controlled by tho Boil oisture blocks. And reslte are enoouraging. Moreover, the laboratory facilitie aro available at Mollka W. such as tho presBure plato and the presBure nembrane apparatus. Therefore relationghip of readings on sypsun blocau to goil soction can bo stablighed for difforant soilse Tho goil moigturo motors uro inexpensive, US dollars 270 por nit (tof Galifornic), tho paun block US $ 6.- por nit. In addition to the faotora limiting product ion l6vols such as salinity, lund lovelling and ovorirrigatian sooug congiderati on Bhould be givan to tho weod oontrol. It Doons that wu odu along channol bunks aro a major sourco of voud infeutation. And WOudu Dhold not bo poraittod to go to good, thy can bo controllud by D 2 periodic burning or with careful use of herbicides. The author states (pago 31) that presen tly little ofthe work being attempted at IAR has relevance for the irrigated state farnso HOwever, the moeting had been held én 11 May 1989 where the workplan proposed by the writer was discussed. And the represen tatives of state farms were alao prOsent. I believe that such trials as evaluatin of surface irrigation, pre-irrigati on of cotton and wheat and study of crop water requirements have relevance for the Amibara Project. In the part proposals and recomnendatins page 36 "sectim 53 the investigation on the field applioatian offioiencies for furrow irrigation is recommended. Such studies worl already susEOsted by the riter as the part of the stuiies on surface irrigation. here were also such studies at Nelka Werer before see A. Kandiah evaluation of furrow irrigation system for cotton. TAR, 1989. As conceming leeching and land re clamation trials (sectin 5.5. page 3) the preliminary agreement had been reached between ADPI and TAR that the land. to the north-east of the Pilot Drainage Area (Melka Sadi) adjacent to the field 4c/10B could be used. Tho area had bean selected by Sir. W. Halcrow for their trials on open fiold draing, but the sito was finally abandoncd. The advantages of that location is iscussed in the soil and groundwater Monitoring Programne (1P, 1989 page 9). The author fomd that during July 1989 the frequency of irrigatim was generally too high (P.38). Hovover, Go Haider, Mellkau Riga reported ovor-irrigation during low demnd period of April and May nd mder irrigation during rost of the growing soason (See EIH /82/014 ield Document No 5 August 1987). AS oonooming tho trials on irrigatian froquency recomnendod by tho author (pago 38), such exporiman ts had be0n APPENDIX 2 Rel. No. Melka Varet Dec, 7_ 19 39 THE PEOPLE'S DEMOCRATIC REPUBLIC OF ETHIOPIA WATCIR RESOURCES DEVELOPMENT AUTHORITY PROJECT CONTROL CCNTRE Ani bara Drainage Project Water ResourceB Devolopment Authority Addis Ababa che above aubject. A0 po your request, we beroby glvo vOm0 conunentu on fu of tho artícloo çtatod in tho roport. 1. Page 4. Climatic Dataj- Under thig article the variablo featuu of tho recorda of ralnfall is Dontlonod, Vith roupact to thio, ovonth0ugh, thoru l0 Do apparont roauon for the extn-0ruinnry dillorencca HATER RESOURCES DEV.AUPEORITY Ani barm Projuct Control Centar Sub- Comnonto on Irrigation /Agronouy neport July-August 1989 by Sir M.MacDonald Wo rofer to your letter lof No TD 254/1,dated 14 Nov, 1939 rcgurding between the oavailablo rocordu of roul pitua tionu on uito. rain•ull, wo would 1iko to glve aom0 The ruinfall oharaotorlutio0 of tho roglon lo vory orrutic, non unlforu & rovoalo a markud Vuriab1llty with in uhort dislanceu leog than u kilomotor, Thoro uro 4 othor clauo V ruingugu ultuu w1lh ln tho for whch uva1lublo rucordu wit1 vupuct to that of p1ojoct au TUlativoly lov0r valyug & utill varylng in thu LAN givo othor. wngnltudu ron uuch A PPENDIX Iel. Na Melka Warct Dec, 1 19 39 THE PEOPLE'S DEMOCRATIC REPUBLIC OF ETHIOPIA WATER RESOURCES DEVELOPMENT AUTHORITY PROJECT CONTROL CENTRE Anlbara Drainage Proiject Water Resources Developpent Authorlty Addis Ababa WATER RESOURCES DEV.AUPHOIRITY Auni baru Project Control Centar Sub- ConnentB on Irrigation Agronouy Report July-August 1989 by Sir M.MacDonald the above subject. A0 per your requaBt, We herobyy give BOme comirents on fow of the articleu gtatod in tho report. 1. Page 4. Climatic Data /- Under this article the variablo fea tuu Ve refer to your latter Ref No D 25A/1,da ted 14 Nov, 1989 regarding of the recordg of ralnfall is mentlonod, With oventbough, thoro 10 Do apparont between the available rocordu of roal oltua tionu on olte. roason for thu ext-ordinary difforcncci rainfull, we vould 1iko to give somu roupoct to thio, The rainfall oharactorlutios of tho Uglon lo vory oratic,non uniforn & rovoale a l609 than a k1lomotor. Thoro are 4 othur clauo IV rulngusgu ultou w1th in tho projoct arvu for which uvallublo Tucordu with rvupuct to thut of th0 IAl Elvu Tulativoly loWur valuuu & utill vurying 1n magui tudu erou vuch othor. na rkud Vuriability with in uhort disLanceu conducted at MolkawOreT boforo and final concluoiong were establighed for uso at A(five& inlendy 2. sOL ID GROUNDHATOR NONTITORITG PROTRAIIE FOR 1932-1990. PÅlot Drainage Area Studies paço 8 In addition to rehabilitatian of equipment and restoring of standard obsorvation procedures by AP there is an ugent reod to improve hydraulic characteristics of tho Prinary Drain SD 2. It seems that thero is problem with the slope and outflow of ater is difficult. Cansequently in the Fields 4c/6 and 4c/7; out of the three test lines (D 3, D8 and D 13) only the tro drains cun be studies. The outlet of the drain D 13 is subnorgod for much o£ the tine. Similarly in the Fiold 4c/1OA tho drain No D 24 is also subzergod and the two test lines can be nly invotigatod. Tho iprovonent of the Drain SD2 will bo neces sary for proposod leaching trials l0cated to the north-east of tho Pilot Drainago Area (Helka Sadi). It is alao sugrestod that tho IAR activity ohould also inclde cooporati cn on monitoring of drains (analysio of rosults); study of entranco resistance and tho rolationship between hoad and dischargo. The latter had boen investigatod by G.Haidor (FAO export) soe. Haider G. and Melkamu Regea 1987. oni toring of Melka Sadi Pilot Drainage Schemo. Hovevor tho AR activity at investigatian of changos i INVESTIGATIONS Pilot Drainage sch eno will inclu n soil salini ty ovo do chiefly r time. SPECIAL PROBLWS (Aotivity 16 Fig.4) Goils sugrostod for tho IAR cannot bo More dotailod investigation on boron and/or tho volcanio tuf Still tho Molkaweror Canter is in the prooess of improvng tho laboratoy canà ucted in he poriod 1939-190. facilitiog (instrunan ta and 1990) the more compllicated analyois aro not possible. manpowor). mlese it io dono (y tho nd of a 2 One poBBible reason for the high rainfall records of the IAR o tation 1o that the otation ir surrounded wíth sufficlently grom bushes and trees mOrving as wind broako, but not close to the gunge ng to reduce the guge catoh, The locationg of the rest of the rain gm geo are rolatively in anopen aroa. In an area l1%e Amibara where preoipitation is nornally coa,pled with strong wind, the absence of wind shield around the gauges educes the catch by about 20% imparting an up ward acceleration to precipitation about to enter and reaultsin in a deficient catch. The variability in the rainfall records of the project area has been noticed long ago by the Water MAnagement Unit of the P.C.C and for practical purposes, we have be en ueing the averages of the available recordB, The cae can also be taken to the attention of the National Neteoro logical Services Agency for detailed study of the rainfall behavior or in case there naybe a posslb1lity to reconcile the existing difference besed on the sites' situations. 2. Page 5. Ground Water Levels and Salinity In analysing the piezometer data, no account hag been given to the existing land use which najorly 1influences the water level in each of the piezometer. The 71 paezome tere are 8ituated in such away that they give a good coverage of the area. Presently, however, the area these piezome ters are representing donot bave a unifoIm and practice. Some of the piezoneters are located in an area continuous irrigation has been inherently with held because of the throwal of where irrigation caltivation for reasons of salinity. State formg the land out of BOme of the fields to introduce Bome salt tolerant crops resuming irrigation have also reinstated after a long period of on the trend of the piezometers readings. interruption and this again has its owm influence towarde higher water table levelg-contrary to the As etated in the report existing GWT records reveal gradual trend Decauge most of the area where gXound water depths whre 2m and the previous prediction B01ls are highly salime have arready been out of cultivations and irrigation LB ala0 permanently discontimued, GT recordg with in such an area have even a felling trend. Thuo, the set of evento under which the data was collected vary [rom one areA to ano ther to the extent that complioations arise to derive a general conclueion representing the ground vater of the project area. table trend We suggeet a comprehensive GWT record analysis in conjunction with the land uge detaile of the project farms to derive better conclusione. Pago5. Irrigation water eupply- Under this article in trying to Juetify the dependence of the irrigation water supply only on the river run and the absence of any correlation betreen irrigation water use & rainfall, the low figure for the 1988 is referred. This appears to contradict with the statement under article 2.3 which mentions "exceptional ralnfall in August 1988 when 262. 4m.., Furthermore, the low figure ls because of a cons1derable hectarage emained unplanted to cotton because of shortage of irrigation water during per-irrigation & planting periods of the year. of the project area, flactuation 1n ater u8e fron year to year was due to the fact that,during the last four years, state farms have trled to introduce double crops like broom Borghum, wheat, cora and barricot bean, Water Bupply records indicated in the report also include irrigation water that hAg been utilized by these crops. No mention has, alao, been mAde about totAl exceas irrigation flows rejected back to the river at the extreDe north of tbe proJect area. In general, poro deta1led approach to the vater use would have helped in indicating that nter Bupply haB never depended on the river run, except in May and Juno of 1988 when the to tal rlver dischargo Was lesa than the cumulative irrigation demand of the project farns. As far ao crop produo tion limiting factors aro concerned, the report has made a good covermge of the exieting problema. If arrangements ./4 In addi tion to the salini ty problem which renarkably reduced arm land = 4 = are to be made to effect the propoBals and recommendations we hope that the problems w1ll be approached ys tematically. d CSOUrcs Republic Ethiopia Ethioa Tikdem Oelopmen Authority MR/gZ cc/ Projst Centre Congrol Project Control Cente AfManager Pro ject Operations And Water Management Department W.R.D.A. Addis Ababa RESERVED
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