Role and Function of Humus in Soil with Emphasis on Adsorption of Herbicides and Chelation of Micronutrients

Abstract

Humus, representing less than 5% of the dry weight of soil, imparts unique and remarkable properties to the inorganic matrix of sand, silt, and clay. It is to be regarded as a positive asset in crop production. In addition to its well-known effects on physical, chemical, and biological processes in soil, humus plays a key role in the behavior of pesticides and the solution and transport of micronutrients to plant roots. Interaction of humus with organic pesticides and other potentially toxic pollutants and complexation of transitional metal ions, particularly those essential for plant growth are discussed.