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.
They transport chemicals very readily and have very little capability to retain them. Top Pesticide movement ratings Pesticide movement ratings measure the tendency for pesticides to be carried through the soil below the root zone. Persistence is a measure of the length of time the chemical remains active in the soil. Mobility is a measure of a chemical's tendency either to move through soil with leaching water or to be retained in the soil by sorption on particles of clay and organic matter. A high Koc value means a chemical has a strong tendency to bond to soil organic matter.