Role of Microorganisms in Carbon Cycling in Soils

Abstract

The agricultural crops are dependent on inorganic nitrogen for growth, and the amounts of plant-available ammonium- or nitrate-nitrogen are limited in the soil. Microorganisms play an important role in improving soil fertility and involved in all aspects of N cycling, including N2 fixation, nitrification, denitrification and ammonification. They decompose plant residues, soil organic matter and release inorganic nutrients that can then be taken up by plants. The environmental factors have direct and indirect effects on soil nutrient turnover processes, including N cycling. Thus changes in N dynamics in soils are closely connected with altering in microbial activities. The knowledge of the factors influencing soil microorganisms involved in N cycling is fundamental for sustainable environmental management. This chapter presents an overview of the role of microorganisms in N cycling and also elucidates whether biotic and abiotic factors alter their population and activities.