Movement of phorate under constant and variable surface water flux in initially dry and moist soils

The distribution of phorate was studied in three texturally different soils under constant and variable surface flux of water. Phorate distribution profiles and leaching curves showed that the insecticide was displaced more efficiently and its concentration peak formed at deeper depth with constant than with variable water flux in sandy loam soils irrespective of initial soil water content. However, phorate distribution profiles were found to be independent of the methods of water application in clay soil because of its extremely low permeability.