ABSTRACT

The behavior of pesticides in soil and water is regulated by the properties of the compounds and the media, and by climatic conditions. Important properties include ionizability, water solubility, vapor pressure, soil retention, and longevity. Carboxylic acid herbicides and growth regulators, hydroxy acid pesticides, aminosulfonyl acid herbicides, amide and anilide herbicides, carbamate and carbanilate pesticides, fumigants, and highly water soluble nonionic pesticides are weakly retained by soil colloids and are relatively mobile in soils. Quartemary N pesticides are very highly basic compounds, with very high water solubilities and very low potential for volatilization. Soil organic matter has been the major constituent in soil reported to bind acidic pesticides, but metallic hydrous oxides are also likely to be involved, particularly in tropical soils. The phenylurea pesticides have short to moderate longevity. The chemicals are degraded in soil by microbial degradation, and bacteria are the organisms primarily involved.