Soil Organic Matter and Microbial Role in Plant Productivity and Soil Fertility

Abstract

The organic materials that become a part of the soil matrix are soil organic matter (SOM) which is the mainstay of soil quality. The heterotrophic microorganisms are the key players for degradation of organic matters by different enzymes due to assimilation of substrate carbon and energy for their nutrition. The SOM holds a key for sustained food production in a number of ways such as increased nutrient and water-use efficiency, improved physical properties of soils and improved biological activity. The temperature, O₂ supply, rainfall, parent material, soil fertility, biological activity, nature of the substrate, land use pattern, etc. are the important factors controlling the rate of decomposition of SOM and thereby the status of soil organic carbon (SOC). Deterioration of soil quality, especially SOC and its associated nutrient supply to soil, is one of the major factors for yield decline or stagnation under intensive cropping system in most of the countries. Agricultural intensification has resulted in loss of carbon to atmosphere, and its contribution to green house is also a serious problem. The SOM is the most vital parameter that needs to take care for restoration and maintenance of soil health vis-a-vis soil fertility and crop productivity. This can be done mainly by adopting different technological options like C sequestration, balanced and integrated nutrient management (INM), improving quality and quantity of FYM, compost, vermicompost, green manure, mulch farming, incorporation of crop residues and recycling, production and promotion of bio-inoculants, increased forestation, choice of cropping system, etc.