In designing an irrigation system, it is necessary to know how much water in a soil is available to plants. The difference in the moisture content of the soil between field capacity and the permanent wilting point is called the available moisture. This represents the moisture, which can be stored in soil for subsequent use by plant.
Solid Type | Percent Moisture Weight | Based on Dry of Soil | Depth of Available Water per unit Depth of Soil cm/m Depth of Soil |
Fine Sand | 3-5 | 1-3 | 2-4 |
Sandy Loam | 3-15 | 3-8 | 4-11 |
Silt Loam | 12-18 | 6-10 | 6-13 |
Clay Loam | 12-18 | 7-16 | 10-18 |
Clay | 15-30 | 12-20 | 16-30 |
