有机培肥对红壤坡耕地产流产沙的影响

采用侵蚀小区田间监测方法,研究秸秆覆盖、生物质炭和猪粪等有机物料添加对红壤坡耕地产流产沙的影响。结果表明:2015年红壤坡耕地侵蚀量达到36 t/hm~2,78%~86%发生在花生季,达到中度侵蚀。与对照(CK)处理相比,单施化肥(NPK)处理没有降低产流产沙(P0.05)。与NPK处理相比,秸秆覆盖(NPK+Str)处理显著降低了产流产沙(P0.05);生物质炭(NPK+BC)处理显著降低了产流(P0.05),但是减沙效果不明显(P0.05);猪粪(NPK+SM)处理尽管提高了地表径流(P0.05),但是显著降低了产沙(P0.05)。秸秆资源在该区匮乏,秸秆覆盖难以推广。生物质炭的团聚能力弱,颗粒小,质量轻,易随水流失,在坡耕地上改良效果不明显。猪粪在该区资源丰富,不但提高土壤肥力,促进了团聚体形成,而且水土保持效果好,是该区农业生态环境可持续发展的重要措施之一。

Effect of Organic Amendment on Runoff and Soil Erosion in Slope Cropland of Red Soil

This study investigated the effects of straw mulch, straw-derived biochar and swine manure on runoffs and erosion rates in slope cropland of red soil based on the monitoring data of erosion plots. The results showed that soil erosion rate reached 36 t/hm² (belonging to middle erosion level) in 2015, in which 78%-86% occurred in peanut season. Compared to no fertilization (CK), NPK treatment (only chemical fertilizers) did not reduced runoff and erosion rate (P>0.05). Compared to NPK treatment, straw mulch treatment (NPK+Straw mulch) significantly reduced runoff and erosion rate (P<0.05), biochar treatment (MPK+biochar) only significantly decreased runoff (P<0.05), and swine manure treatment (NPK+Swine manure) increased runoff (P<0.05) but decreased erosion significantly (P<0.05). In red soil region, straw resource is rare so straw mulch is impossible as a common measurement for erosion control. Biochar is prone to be eroded due to its low binding energy, fine particles and low density, so no positive effect was observed in this study. Comparatively, swine manure, as a plentiful resource, can increase soil fertility and aggregate stability and reduce soil erosion considerably, thus, is a good conservation practice in slope cropland in red soil region.