See Table 3 for associated values. 2 Higher numbers mean greater soil retention. This measure refers to how readily the herbicide dissolves in water. Water solubility plays a major role in determining the fate of herbicides in water, soil and air. An herbicide that is water soluble will not be retained by the soil.
Volatility refers to the tendency of the herbicide molecule to become a vapor.
C is an index of this characteristic. Herbicides with high vapor pressures are likely to escape from the soil and volatilize into the atmosphere. This may result in the unwanted movement of herbicide to sensitive areas or a loss of effectiveness at the application site. Soil retention is an index of the binding capacity of the herbicide molecule to soil organic matter and clay. In general, herbicides with high soil retention are strongly bound to soil and are not subject to leaching.