A REVIEW OF THE EFFECTS OF PESTICIDES ON MICROBIAL ACTIVITY IN SOILS

The paper reviews the recently published literature (mainly since 1970) on the effects of pesticides on the major biogeochemical cycles in soils, including transformations of carbon, nitrogen, phosphorus sulphur, trace elements and soil enzymes. The main conclusion is that pesticides, with the exception of fumigants and some broad spectrum fungicides, have little deleterious influence on soil processes when applied at field rates. Obvious gaps in our knowledge of pesticide-soil interactions are pointed out and suggestions are made where future research is needed. In the absence of effective biological control methods, the extensive use of pesticides in agriculture will continue. It is essential that the effects of these compounds on biochemical transformations in soils be determined, so that we can arrive at a balanced view of their effects on soil fertility.