Potential and Challenges for Carbon Sequestration in Agricultural Soils

Agriculture occupies a larger portion of global land area (about 35%) than any other human activity (Betts and Falloon, 2007). Agriculture soil stocks have been suggested as potential measure to sequester atmospheric CO2 to help stabilize its concentration in atmosphere and has been estimated that 0.4-0.9 Pg C year-1 can be sequestrated within global agricultural soils (Paustian et al., 1998). This has been supported by the fourth assessment made by the Intergovernmental Panel on Climate Change, that identified agriculture as among the economic sectors having the greatest near-term (by 2030) greenhouse gas mitigation potential, largely via soil organic carbon (SOC) sequestration (Smith et al.,2007). However, currently, there is much uncertainty and debate due to uncertainties associated with quantifying the impact of the various crop management practices on green house gas emission ,the spatial and temporal scales involved in quantifying greenhouse gas emissions from, and C sequestration in, agro-ecosystems, uncertainty of future climatic conditions that affect type of crop mana...