BOUND (NONEXTRACTABLE) PESTICIDE DEGRADATION PRODUCTS IN SOILS - BIOAVAILABILITY TO PLANTS

A significant proportion of degradation products from certain pesticides applied in agriculture remains in soils as bound (nonextractable) residues. Soil organic matter is largely responsible for the formation of bound residues. In addition to chemical binding, the degradation products of pesticides are also firmly retained by soil organic matter fractions to form bound residues by a process that more likely involves adsorption on external surfaces and entrapment in the internal voids of molecular sieve-type structural arrangements. The bound residues of pesticides degradation products in soil are bioavailable to plants.