Role of Soil Organic Carbon Sequestration in Climate Change Mitigation and Sustainable Agriculture: A Comprehensive Review

Abstract

A significant method for reducing greenhouse gas emissions while enhancing the environmental quality and profitability of agricultural systems is through the process of soil organic carbon (SOC) sequestration. This review assesses the effects of SOC on climate mitigation, the sustainability of food production and the enhancement of soil health. Globally soils are estimated to store about 1500 to 2400 Gigatons of carbon which represents three times more carbon than exists in the atmosphere or all plant biomass; therefore, the maintenance of SOC is an important mechanism for controlling the climate. This review integrates what is currently known about the mechanisms of SOC, the influence of various factors on SOC, the management practices which can increase SOC, and the quantitative reduction of greenhouse gas emissions possible from SOC sequestration in a variety of agroecosystems. Results show that conservation agriculture, agroforestry, cover cropping and biochar additions can result in the sequestration of 0.3 to 2.0 metric tons of C/ha/year, although large variability exists among soils and climates based upon management practices. In addition to the reduction of greenhouse gases, SOC-enhancing management practices have many additional benefits including improved water retention, improved nutrient cycling, improved biodiversity, and improved crop yields. However, to achieve global greenhouse gas emission reductions will require the adoption of these practices over billions of ha of land and will need to be implemented within a supportive regulatory framework, economic incentive program, and innovative technology. This review presents a complete assessment of the literature for those who would like to develop policies, practice and research related to SOC sequestration for reducing greenhouse gas emissions and improving the sustainability of agricultural systems.