不同耕作模式下坡耕地次降雨径流量及径流泥沙颗粒机械组成规律

为确定坡耕地在不同耕作模式下,次降雨坡面径流量及径流泥沙中土壤颗粒机械组成规律,在天然降雨条件下,采用10°坡耕地,顺垄、横垄、免耕、秸秆覆盖耕作模式组合试验。结果表明:不同耕作模式试验小区的次降雨径流量顺序为裸地(LD)>顺垄传统耕作(Ts)>顺垄免耕(NTs)>顺垄免耕秸秆覆盖(NTSs)>横垄传统耕作(Th)>横垄免耕(NTh)>横垄免耕秸秆覆盖(NTSh);不同耕作模式下,坡面流失的泥沙颗粒机械组成均不同,其中LD流失的沙粒含量最多,Ts流失的粉粒含量最少,NTSh流失的粘粒含量最多;不同耕作模式,坡面流失土壤颗粒级配较均匀地为LD、NTs、Th、NTh;不同耕作模式产生的地表径流中,粒径在0.25～0.06mm的土壤流失量最多,当粒组的范围>0.06mm时,各粒组不同处理方式的土壤流失量顺序均为NTSh

Slope Cultivated Land Rainfall Runoff and Sediment Mechanical Composition in Different Tillage Patterns

In order to determine the law about mechanical composition of soil particle size in the slope farmland runoff and sediment under different tillage patterns.Using skimming ridge,horizontal ridge and no-tillage sraw multhing in 10° farmland to composite test.The results show that the order of runoff in different cultivation mode is as follows: Bare framland(LD) >traditonal and skimming ridge farming mode(Ts) >no-tillage and skimming ridge farming mode(NTs) >no-tillage straw mulching and skimming farming mode(NTSs) >traditional and horizontal ridge farming mode(Th) >no-tillage and horizontal ridge farming mode(NTh) >no-tillage straw mulching and horizontal ridge farming mode(NTSh);under different tillage mode,sediment particle size composition of slope water and soil conservation are different,the sediment of LD sand particle content is significantly higher than other pattern,which under NTSh the clay content is the most loss.The least loss about silt content in sediment is under Ts.Under different tillage patterns,the distribution of sand grain composition was narrow in slope sediment in these mode as follows: LD,NTs,Th and NTh;the surface runoff from different farming mode,particle size in the 0.25~0.06 mm loses the most,when the group particle size range >0.06 mm,the order of soil loss in different particle size and different mode range is as follows: NTSh