紫色土坡耕地不同施肥水平下氮随径流流失特征研究  

Effects of Different Fertilization Level on N-losses alone with Surface Runoff on Slope Land of Purple Soil

作　　者：姚军[1] 唐春霞[1] 何丙辉[1] 

机构地区：[1]西南大学资源环境学院三峡库区生态环境教育部重点实验室,重庆400715

出　　处：《水土保持研究》2010年第2期54-57,共4页Research of Soil and Water Conservation

基　　金：农业部重点科技项目"种植业源污染物流失系数测算"(WX-Z-20-1);国家自然科学基金(40671115);重庆市自然基金重点项目(2007BA1015);西南大学生态学重点学科"211工程"

摘　　要：采用径流小区定点监测,研究了紫色土坡耕地"冬小麦-夏玉米"种植模式下不同施肥水平处理氮随径流流失特征。试验结果表明:产流量与降雨量变化趋势基本一致。在同等施肥水平下(583.20kg/hm2),常规处理(农家肥+化肥)中,总氮、硝态氮及氨态氮的浓度变化不显著,各处理氮流失系数分别为:常规处理1.82%,优化处理2.66%,横坡垄作0.51%,横坡垄作中总氮、硝态氮及氨态氮流失量较优化处理相应减少了60.4%,73.2%,53.9%,较常规处理总氮、硝态氮相应减少28.8%,10.4%,氨态氮增加2.4%。在同等种植模式下(顺坡),增量处理(施肥量增加50%),氮流失系数为2.46%,总氮、硝态氮及氨态氮流失量较优化处理相应增加23.3%,11.1%,69.1%。在外界因素如"前期降水较少、施肥后短期内出现较大强度降雨等"强力干扰下,各形态氮素流失量显著增加,且有随施肥量增加而增大的趋势。Through monitoring the runoff in plots, the N--loss was studied under different fertilization lev- els with winter wheat--summer maize rotation on the slope land of purple soil. The results showed that the amount of runoff was consistent with rainfall. Under the same fertilization level （583.20 kg/hm2）, for the conventional treatment, the TN, NO3--N and NH4--N did not change significantly; the coefficients of N--loss are as follows： 1. 82% with conventional treatment, 2. 660/00 with optimization treatment and 0.51% under cross--ridge. Compared with optimization treatment and conventional treatment, the TN, NO3--N and NH4--N reduced 60.4%, 73.2%, 53.9% and 28.8%,10.4%,--12.4%, separately under cross ridge treatment. Under the same plantation mode, incremental treatment （fertilizer increase 50%）, the N--loss coefficient is 2.46~//oo and the TN, NOa--N and NH4--N increased 23.3%, 11. 1%, 69.1% compared with optimization treatment. The results also showed that the disturbance under external factors such as little precipitation and a heavy rainfall shortly after fertilization, will increase the N--loss signifi- cantly, and the loss increased with increasing fertilization.

关 键 词：紫色土 施肥水平 流失量 流失系数 

分 类 号：S157[农业科学—土壤学]