Top Soil sensitivity ratings Soil sensitivity is a composite measure of a soil's tendency to allow a chemical to be transported all the way through the soil profile to groundwater. Soil sensitivity depends on the soil's leaching potential, its sorption potential, and the hydraulic loading on the soil. Leaching potential is a measure of the driving force available to move chemicals down through the soil. Factors influencing leaching potential are soil permeability, soil depth to bedrock or a water table, soil slope, and the balance between infiltration and runoff. Sorption potential is a measure of the soil's ability to retain chemicals by reactions between the chemicals and particles of clay and organic matter.
Factors influencing sorption potential are the amounts of organic matter and clay in the soil.
Hydraulic loading is the amount of water available at the soil surface to create leaching conditions. Factors influencing hydraulic loading are the amount of rainfall and whether or not the soil is irrigated. EM 8707 Soils having very low or low sensitivity tend to be slowly permeable and high in organic matter. In these soils, leaching is limited and there is maximum retention of chemicals by sorption into organic matter. Soils having high or very high sensitivity tend to be rapidly permeable and low in organic matter.