Strategies and Mechanisms of Building up and Stabilizing Organic Matter Stocks in Soils

Soil organic matter (SOM) has very important functions in the soil. It affects the soil physical, chemical and biological properties, and eventually affecting the overall soil and crop productivity. Increase in SOM matter is associated with an increase in soil and crop productivity. It also contributes to climate change mitigation through soil carbon sequestration. This paper discusses various soil management and/or farming strategies that contribute to the building up of SOM. The paper also highlights mechanisms that stabilize organic matter in the soil and protect it from rapid decomposition and its loss from the soil. Through reviewing of various research papers, literature shows that a number of strategies provide substantial contributions to building up of SOM. These include: conservation agriculture, crop rotations, cover cropping, agroforestry and afforestration, improved fallows, well managed pastures and organic farming. Various physical, chemical and biochemical mechanisms contribute to stabilization of organic matter and protect the accumulated SOM from rapid decomposition. Quantity and quality of organic materials, soil matrix and clay minerals, organo-mineral interactions and soil management practices are all important factors in SOM stabilization. From this review it can be pointed out that research based knowledge of both SOM accumulation strategies and SOM stabilizing mechanisms is very beneficial in making recommendations and implementation of soil management practices that can increase and build up organic matter in the soil.