中文摘要：

通过径流小区试验研究20,40,60m3种坡长条件下人为扰动地表对土壤养分含量的影响。结果表明,人为扰动地表小区的土壤养分含量均低于同一坡长的自然小区。其中土壤全氮、碱解氮、有机质、全磷、有效磷含量在3种坡长差异均显著,20m坡长的土壤有效磷含量差异最大,相差10.21mg/kg,比自然坡面小区少58%。土壤钾素只在20m坡长时,含量差异达显著水平。不同坡长的土壤养分含量,除自然坡面小区的磷素外,其他土壤养分的含量均随坡长增加而增加。不同坡长的人为扰动小区,其60m坡长小区的土壤全氮、碱解氮、有机质含量显著高于20m及40m坡长小区,20m小区与60m小区相比,土壤全氮、碱解氮、有机质含量分别降低36%,39%和46%;土壤磷素、钾素含量是20m坡长小区显著低于40m及60m坡长小区,20m小区土壤全磷、全钾含量分别为0.22,11.17g/kg,40m小区土壤全磷、全钾含量分别为0.35,17.59g/kg。不同坡长的自然坡面小区,土壤磷素含量是40m小区略高于20m及60m小区;土壤氮素、钾素、有机质含量随坡长变化规律与扰动地表小区一致。

英文摘要：

Through experiments in runoff plots,effects of disturbance surface on soil nutrient content under three different slope lengths of 20,40,60m were studied in this paper.The results showed that the soil nutrient contents in disturbance surface plots were lower than that in the natural plots under the same slope length.The contents of total nitrogen,alkali-hydrolysable nitrogen,organic matter,total phosphorus and available phosphorus under the disturbance surface plots had the significant difference with that under the natural plots in the three different slope length.The content of available phosphorus in 20m plots had the greatest difference which was 10.21mg/kg and decreased by 58%,compared with natural plots.For potassium,there was significant difference between the two kinds of plots only in 20m slope length.For the nutrient content of different slope length,in addition to the phosphorus of the natural plots,the other soil nutrient contents increased with the increase of slope length.For the disturbance surface plots in different slope lengths,the contents of total nitrogen,alkali-hydrolysable nitrogen and organic matter in 60m slope length plots was significantly higher than that in 20m and 40m slope length plots.Compared with 60m plots,the contents of total nitrogen,alkali-hydrolysable nitrogen and organic matter in 20m plots decreased by 36%,39% and 46%respectively,the contents of phosphorus,potassium in 20m plots was significantly lower than that in 40m and 60m plots,the contents of total phosphorus and total potassium were 0.22g/kg and 11.17 g/kg in 20m plots,0.35g/kg and 17.59g/kg in 40m plots respectively.For the natural plots in different slope length,the contents of phosphorus in 40m plots was slightly higher than that in 20m and 60m plots.The change law of nitrogen,potassium and organic matter along with the slope length was consistent with that in the disturbance surface plots.