农牧交错区耕作方式下坡面土壤侵蚀对有机碳流失的影响

Impact of Slope Soil Erosion on Organic Carbon Loss in Farming Practices in Agro-Pastoral Ecotone

土壤有机碳是农作物、牧草等植被生长的主要碳素来源,其流失会对土壤肥力具有显著影响。以甘南藏族自治州农牧交错区为研究区域,通过地表径流实验,分析了该地区不同耕作方式下坡面土壤侵蚀对有机碳流失的影响。结果表明:空白对照的年径流量、年侵蚀量和侵蚀强度远高于其他耕作方式,其次为传统耕作;不同耕作方式的可溶性有机碳流失量、土壤有机碳流失量之间均存在显著差异,空白对照的可溶性有机碳流失量和土壤有机碳流失量最多;横坡垄作的可溶性有机碳流失量最少,横坡垄作和秸秆还田的土壤有机碳流失量相对较少;4种不同耕作方式和空白对照的地表径流量与可溶性有机碳流失量、土壤有机碳流失量之间均存在显著正相关关系。综上所述,进行土地耕作可显著减少有机碳的流失,相较而言横坡垄作减少土壤侵蚀作用的效果最好,传统耕作最差。

Soil organic carbon is a crucial carbon source for vegetation growth,such as crops and grass,and its loss significantly affects soil fertility.This study focused on the agro-pastoral ecotone in Gannan Tibetan Autonomous Prefecture,analyzing the impact of slope soil erosion on organic carbon loss under different farming practices through surface runoff experiments.The results indicate that the annual runoff,erosion quantity,and erosion intensity of the blank control are significantly higher than other farming methods,followed by traditional farming.There are notable differences in the loss of soluble organic carbon and soil organic carbon among different farming practices,with the blank control showing the highest losses.Contour plowing exhibits the least loss in soluble organic carbon,while both contour plowing and straw returning result in relatively lower soil organic carbon loss.Significant positive correlations exist between surface runoff,soluble organic carbon loss,and soil organic carbon loss for the four farming practices and the blank control.In summary,implementing appropriate farming practices can significantly reduce organic carbon loss,with contour plowing being the most effective in reducing soil erosion,and traditional farming being the least effective.