Critical aspects of organic matter management in the Tropics: the example of India

Organic matter is the life of soil. It enables a soil to perform efficiently its primary function of supporting plant growth. Its endemic deficiency in tropical soils, particularly those under the influence of arid, semiarid and sub-humid climates, is a major factor contributing to their low productivity. Research over the past 30 years, formatted as long-term experiments, has conclusively proven that those treatments and practices that supported organic matter build-up, also favored sustainable productivity. Since sustenance of organic matter necessitates regular additions, bolstering its supplies in sufficient quantities is a strategy suggested for the future. While in-situ cultivation and non-competitive use are the common elements of an overall scheme on reinforcing an organic matter reservoir, traversal routes for harnessing, however, vary with the kind of organic resource being aimed at. For instance: with cattle dung and human excrements, conversion into biogas is considered necessary; farmer participatory appraisal and emphasis on dual purpose legumes are found to be essential in spreading green manures, and non-palatability to cattle with a pre-composting step seem vital to succeed with crop residues. Possible research, development and policy initiatives are outlined to enlarge supply and efficient use of different types of organic resources.