Prof. D. J. Bagyaraj, Chairman, Centre for Natural Biological Resources and Community Development, Bangalore

Soil Biodiversity – Status and Recent Advances

Abstract: Soil biodiversity is the study of biological systems occurring in soil. The living organisms in soil range from microorganisms, small and large invertebrates and small mammals. Macrofauna contribute to improve soil structure, aeration and water infiltration.  They predate on soil organisms and help to maintain biological equilibrium in soil. Mesofauna are important plant pathogens. Microfauna are important predators of bacteria and algae, thus regulating their population in soil. Algae are photosynthetic and aquatic. Algae and lichens contribute to soil formation from rocks. Algae also contribute to soil aggregate stability and some of these fix atmospheric nitrogen. Fungi play a role in decomposition of organic matter, promotion of soil aggregation, nutrient cycling and biocontrol of plant pathogens. Some of them are edible. Some cause disease in plants and animals. Bacteria are common in soil environment and play important role in nutrient cycling, organic matter decomposition and in the production of industrially important secondary metabolites. Some of them cause disease of plant. Ecosystem services are the benefits people obtain from the ecosystem. Soil organisms are responsible for many of these services like nutrient cycling, control of pests and diseases, formation of soil, degradation of wastes and harmful chemicals, and production of goods like food, fuel, fiber etc. In recent years industrial microbiologists have started looking into the soil for organisms which are capable of producing various substances including antibiotics, vitamins, hormones and enzymes. The results obtained so far have revolutionized the industry in many countries. The objective of this paper is to review the state of knowledge of soil biodiversity, its functions, its contribution to ecosystem services and its relevance for the sustainability of human society.