Amibara Drainage Project Phase-II - Soil Survey Summary
Project Overview
Project: Amibara Drainage Project Phase-II
Client: Government of Ethiopia, Ministry of Water Resources
Consultant: Water and Power Consultancy Services (India) Ltd
Document: Soil Survey/Soil Classification Data/Analysis (Annex-4B)
Location: Amibara Cotton State Farm, Ethiopia
Survey Period: October 1995 - February 1996
Key Findings
- 86 auger bore samples collected across the cotton state farm
- Detailed soil profiles recorded up to 520cm depth
- Parameters recorded: color, texture, consistence, reaction to HCl, EC, pH
- Groundwater depth varied from 103cm to >500cm across sites
- Groundwater EC ranged from 0.82 to 18.29 dS/m (showing significant salinity variation)
- Groundwater pH ranged from 6.76 to 8.56 (mostly neutral to slightly alkaline)
Soil Characteristics
| Parameter | Observations |
|---|---|
| Texture | Varied from sandy loam (SL) to clay loam (ZCL) with some sandy (S) and loamy sand (LS) layers |
| Color | Predominantly 10YR hue (yellowish-brown) with value/chroma of 3/2 to 4/3 |
| Consistence | Ranged from loose to very firm, with most layers described as friable |
| Salinity | Surface EC (1:2) 0.14-8.50 dS/m, with some highly saline patches noted |
| pH | Surface pH 6.90-8.60, generally neutral to alkaline |
Notable Observations
- Presence of impermeable layers at varying depths (often between 200-450cm)
- Occurrence of lime concretions and mottles in many profiles
- Some sites showed signs of salinity with white crusts at surface
- Texture often became finer with depth, with clay layers below sandy layers
- Several abandoned areas noted with high salinity and poor vegetation
Recommendations
- Drainage design should account for variable impermeable layer depths
- Salinity management needed, especially in areas with high groundwater EC
- Soil amendments may be required for areas with high pH
- Further investigation recommended for areas with abrupt texture changes
- Monitoring of groundwater levels and quality suggested for sustainable irrigation
Note: This summary highlights key points from the detailed auger bore descriptions. For complete data, refer to the original document with all 86 bore logs.