Sustainable soil management and its role in mitigating greenhouse emissions

Increasing concentrations of greenhouse gases such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in the atmosphere and the consequent climate change have irreversible effects on the environment and human health. Greenhouse gases in the soil are produced by microbial activity, root respiration, chemical decomposition, and heterotrophic respiration of organisms; the carbon flux from the soil in the form of carbon dioxide is caused by respiration and other activities of soil organisms, nitrous oxide is produced by nitrification and denitrification processes, and methane is produced by microbial methanogenesis under anaerobic conditions. This is while various environmental and managerial factors might affect their concentrations in the soil. Proper management of agricultural soils offers a significant potential to reduce greenhouse emissions. For instance, crop rotation, cover crop farming, conservation tillage, crop residues retention, and avoiding plant residue burning or removal serve as appropriate management practices to reduce carbon dioxide emission. Strategies employed to mitigate nitrous oxide emission include better nitrogen management, well-planned application of nitrogen fertilizers only to meet crop requirements in a timely manner, reduced application of nitrogen fertilizers tailored to the different stages of plant growth, using Legume plants in crop rotation, proper crop residue management, use of slow-release fertilizers, and application of nitrification and denitrification inhibitors. Methane emissions may be reduced through drainage of rice paddies to provide adequate ventilation for methane oxidation and tillage or composting to decompose crop residues before flooding.