The effects of various soil factors and amendments on the degradation of pesticide mixtures.

Soil disposal is the most common method of handling dilute pesticide wastes. The effects of several soil factors on the degradation of a pesticide mixture were investigated. Atrazine, captan, carbaryl, 2,4-D, diazinon, fenitrothion, and trifluralin were studied under varying laboratory conditions of soil type, pH, moisture content, organic matter content, microbial activity, and pesticide concentration. Of the variables investigated, pesticide concentration was the single most important factor with degradation rates much slower at high (1000 ppm) levels of fortification than moderate (100 ppm) levels. Under most conditions, chemical degradation was at least as significant as microbial degradation. Effects of other factors varied considerably and were pesticide dependent.