免耕的固碳效应研究进展

Research Review of the Effect for Carbon Sequestration Under No-tillage Agriculture

免耕是一种保护性耕作,可显著地增强土壤的固碳能力。土壤有机碳的获得或者损失取决于生物或有机质剩余的碳增加量与作物收割、微生物化或者分解过程中的碳丢失量这二者的比率。农田耕地的废除恰好可以使作物残茬分解速率降低、土壤有机碳增加。而与土壤耕地有关的几个因素加速了残茬的分解。秸秆还田的手段通过微生物分解的方式提高了对损失碳的利用。免耕提高了农业可持续性能力和抵消人为因素的温室气体排放。总CO2释放量的50%发生在夏季。研究中CO2平均年释放数据表明NT释放量低于常规耕种系统,表层碳积累量明显高于常规耕种系统。除了提高土壤的固碳能力以外,免耕对土壤质量参数产生好的影响,改善了土壤结构,提高了土壤渗透率,减少了流失和侵蚀,这些提高很大程度上是土壤表层有机质积累的结果。文中指出,中国应加强土壤固碳能力的研究,并适度的推广免耕政策。

This is the institution of a review article. The current study shows that no-tillage, also called conservation tillage, is and planting which covers 30% of the soil surface with biosolids to reduce water erosion. The net gain or loss of soil organic C depends on the relative rates of C additions as plant biomass and organic residuals versus that lost through crop removal, microbial respiration and erosion. The elimination of tillage tillage generally results in slower residue decomposition and a net increase in SOC. In contrast, a number of dependent factors generally increase the rate of residue decomposition. Incorporation of residues into the soil increases their availability for loss through microbial decomposition. No-tillage increase the sustainability of agriculture and offset the release of greenhouse gas related to human action. The 50% release of CO2 comes about in summer. The research suggest that the average CO2 release quantity per year of notillage is lower than traditional tillage, the carbon quantity accumulated in surface soil of no-tillage is higher than traditional tillage. Additional benefits of continuous no-till management have been recognized including its positive impact on various soil quality parameters. Soils managed using no-till have improved soil structure, increased infiltration and reduced runoff and erosion. These improvement come about, in large part, as a result of the accumulation of organic matter at the soil surface. The authors pointed out that the further study on carbon fixation ability of soil should be enhanced, and the policy on no-tillage should be encouraged.