中文摘要：

以重庆市忠县水土保持试验站为研究平台,对小区尺度下＂大横坡＋小顺坡＂耕作模式对氮及径流流失的影响进行研究,结果表明：与全顺坡模式比较,6m顺坡＋2m横坡模式,5m顺坡＋3m横坡模式和4m顺坡＋4m横坡模式径流量分别减少了41.74%,45.84%和59.63%;在总氮流失上,在降雨历时为6.62～16.32h,3种＂大横坡＋小顺坡＂耕作模式之间无显著差异,当降雨历时小于5.12h时,4m顺坡＋4m横坡模式与其他3种模式差异性显著,以4m顺坡＋4m横坡模式保持总氮效果最好,其中当降雨历时为2.51h和3.22h时,4种耕作模式之间彼此均存在显著差异;径流中氮的流失以可溶性氮为主,可溶性氮占总氮的比例受降雨强度和降雨历时的共同制约;＂大横坡＋小顺坡＂耕作模式总氮以及可溶性氮单位面积流失总量显著小于全顺坡耕作模式.

英文摘要：

The effect of different straight tillage contour tillage measures in plot on nitrogen loss from runoff and runoff loss have been studied in Soil and Water Conservation Station in Zhongxian County,Chongqing.These results indicate that,compared with runoff under total straight tillage measure,runoff of 6 m straight tillage 2 m contour tillage,5 m straight tillage 3 m contour tillage,4 m straight tillage 4 m contour tillage reduce 41.74%,45.84% and 59.63% respectively.There are no significant differences between four kinds of tillage measures on the total nitrogen loss during the duration of rainfall of 6.62 h-16.32 h.when less than 5.12 h,there are significant differences between 4 m straight tillage 4 m contour tillage and other tillage,and the best effect for 4 m straight tillage 4 m contour tillage.In the condition of duration of rainfall of 2.51 h and 3.22 h,there are significant differences between each other;The soluble nitrogen loss accounts for most of the nitrogen loss from runoff,and the proportion of soluble nitrogen loss accounts for total nitrogen loss is influenced by rainfall intensity and duration of rainfall.The loss of total nitrogen and soluble nitrogen per area of different straight tillage contour tillage measures are significant lower than that of total straight tillage measure.