irrigation+rainfall = evaporation + transpiration + runoff + leaching Which one of these processes do Farmers really have control over during the growing season? If you have the ability to irrigate your sandy soils and water is cheap and plentiful, then you are fortunate and have some control on the left side of the equation. If you do not have irrigation, you must look at the factors on the right side of the equation to see what can be controlled or minimized to benefit your crop. Evaporation from the soil surface can be reduced with mulch or leaving crop residue on the soil surface. Transpiration is a function of the plant leaf surface area and the weather. Runoff is or should be minimal in sandy textured soils with high percolation rates. This leaves the leaching of water out of the root zone as the #1 controllable loss of moisture to your crop. Interrupting the downward movement of moisture in your soil by installing a "smart" barrier can greatly reduce the leaching of water and nutrients. SWRT subsurface membranes detain/retain up to 90% of irrigation or rainfall in the root zone for crop use by disrupting the gravitational movement of water in the soil while still allowing excess water to percolate and do not create anaerobic soil conditions.