Behavior of Dieldrin in Soil: Microplot Field Studies on the Influence of Soil Type on Biological Activity and Absorption by Carrots1

Abstract

An experiment was conducted under field conditions, using micro plots, with the object of studying the behavior of similar concentrations of dieldrin in soil in relation to soil type. Five soil types were used with organic contents ranging from 1 to 70%. The results indicated that persistence, vertical movement, insecticidal activity, and availability of dieldrin residues in soil for absorption by carrots were proportional not to concentration of the insecticide but to the organic content of the soil. It is suggested that in developing environmental criteria for pesticides, it will be necessary to consider not only the results of residue analyses but also the factors which will influence insecticide behavior in soil.