Soil

Monitoring of soil and water quality conditions can be valuable in aquaculture pond management, so some selected procedures will be provided. Most small-scale farmers will not be able to conduct these simple analyses, so comments about visual evaluation of soil also are provided.

Comprehensive soil horizon analysis at multiple sampling locations within each potential site are performed as part of our overall aquaculture feasibility studies whenever soils may be suitable for earthen pond construction. Soil pH testing is done on-site for all boreholes and at multiple soil sampling horizons. General on-site observations on soil type are also be made. A certified United States lab will perform a comprehensive soil texture analysis and soil chemical analysis of all major and minor soil nutrients for multiple samples taken from the most suitable sites. We will then review soil quality test results against optimum criteria for aquaculture.

Soil texture classification is determined by the percentage of sand, silt, and clay in a given sample. From these percentages, soils are then classified by type according to the soil triangle. Soils suitable for earthen pond construction must contain a minimum of 20-30% clay and preferably no more than 30% sand. The best types of soil for aquaculture are classified as clay, silty clay, silty clay loam, and clay loam.  

Soil Quality Parameters for Fish Culture:
Sl NOParametersOptimum range
1ColourBlack or Brown
2pH6.8
3Sand40%
4Silt30%
5Clay30%
6Water retention capacity40% or more
7Nitrogen50mg/100g
8Phosphorous6mg/100g
9Organic carbon0.5-2.75%
10Electrical conductivity<16 dSm-1