中文摘要：

【目的】研究重庆紫色土坡耕地＂冬小麦-夏玉米＂种植模式在不同施肥制度和耕作模式下由降雨而引发的水土流失特征及氮素流失规律,可为该区农业生产及生态环境保护提供科学依据。【方法】设置4种施肥制度（顺坡耕作对照、顺坡耕作农家肥和化肥配合施用、顺坡耕作单施化肥、顺坡耕作单施化肥增量）和2种耕作模式（顺坡耕作单施化肥、横坡垄作单施化肥）,采用野外径流小区长期（2008—2012年）定位监测,研究施肥与耕作对坡面土壤侵蚀及氮素流失的影响。【结果】不同施肥制度和不同耕作模式间产流量、产沙量、氮素流失量差异均显著,不施肥处理产流量、产沙量及氮素流失量均最大,施肥、横坡垄作均能有效降低坡面产流产沙及氮素流失量。与相同施肥水平的顺坡耕作相比,横坡耕作分别减少产流量、产沙量、全氮流失量25.9%、20.5%和33.4%,与相同耕作方式的对照相比,农家肥和化肥配合施用可分别减少产流量、产沙量和全氮流失量35.7%、40.5%和41.2%。紫色土区年降雨量与年产流产沙量均呈幂函数关系（y=axb,a〉0,b〉0）,氮素流失量与径流量呈线性关系（y=ax＋b,a〉0）,但与降雨量相关性不显著,旱坡地氮素流失以总可消化养分（total digestible nutrients,TDN）为主,占全氮的62.1%。农家肥和化肥配合施用可以降低总可消化养分（TDN）和铵态氮（NH4＋-N）占全氮的比例。【结论】紫色土区不宜采取顺坡耕作和不施用任何肥料的管理方式。农家肥和化肥配合施用、横坡垄作是防治重庆紫色坡面水土流失及径流氮素流失的有效途径,径流中氮素流失以总可消化养分为主。

英文摘要：

[Objective] The characteristics of soil erosion and nitrogen losses caused by rainfall under different fertilizer application levels and tillage methods in the cropping of winter wheat-summer maize in purple soil area in Chongqing were studied in order to provide a theoretical evidence for the agricultural production and coordinate land management to improve the ecological environment. [Method] Four kinds of fertilizer levels （treatments of CK, combined application of manure and fertilizer, chemical fertilization, chemical fertilizer with increasing fertilization） and two kinds of tillage methods （chemical fertilization, contour plowing with chemical fertilizer） were designed in an experiment in runoffplots for a long term （2008-2012） observation to study the effect of soil erosion and nutrient loss. [Result] There was a significant influence of runoff, sediment and nutrient loss on different fertilizer application levels and tillage methods, the runoff, sediment and nitrogen loss in the control group （CK） were the largest, contour pIowing and fertilizer reduced the total volume of runoff, sediment and nutrient. The loss amount of the runoff, sediment and total nitrogen in contour plowing decreased by 25.9%, 20.5% and 33.4%, respectively, compared with the loss amount of the runoff, sediment and total nitrogen in cross-plowing plots. The loss amount of the runoff, sediment and total nitrogen in combined application of manure and fertilizer decreased by 35.7%, 40.5% and 41.2%, respectively, compared with that in chemical fertilization in CK. The runoff and the sediment showed a power function relationship （y=axb, a〉0, b〉0）. The nutrient loss and the runoff showed a linear relation （y=ax＋b, a〉0, b〉0）, but no significant relation with precipitation. In dry land, Nitrogen loss was given priority to with total digestible nutrients （TDN）, that accounted for the proportion of total nitrogen was 62.1%, combined application of manure and fertilizer can reduced the proportion of total