耕地土壤碳固存的措施与潜力

Practices and potential of cropland to sequester carbon

土壤CO2排放与土壤退化、土壤有机质(SOC)含量减少和土壤质量下降密切相关.耕地具有较大的碳固存潜力.通过采用最佳管理措施(BMPs)和进行土壤修复来提高土壤质量,能增加SOC含量和提高土壤生产力,并能部分起到减缓温室效应的作用.文章从土壤固碳的机制入手,系统总结了在耕作土壤碳固存方面的研究.从土壤侵蚀控制、退化土壤修复、保护性耕作、残落物管理,改善农作物制度等方面,论述了耕地的固碳潜力,并提出了一系列实现碳固存的措施.最后估算出耕地土壤总的固碳潜力为0.73～0.87 Pg/a.研究表明,在替代性能源开发之前,耕地碳固存是一项切实可行的措施.

Soil emission of CO2 is closely linked to soil degradation, decrease in soil organic carbon (SOC) content and decline in soil quality. Enhancing soil quality through adoption of best management practices (BMPs) and soil restoration can increase SOC content and soil productivity, and partially mitigate the greenhouse effect. Beginning with introducing the mechanism of soil carbon sequestration, this paper systematically summarized the former researches in the field of cropland soil carbon sequestration, then discussed the potential of cropland to sequester carbon through the following ways: control of soil erosion, restoration of degraded soils, conservation tillage, residue management and improvement of cropping system. At last, the potential of world cropland to sequester carbon was estimated, which is about 0.73~0.87 Pg/a. The facts indicate that cropland carbon sequestration is a feasible practice to sequester carbon before the using of alternative energy which is not carbon-based.