玉米苜蓿间作对黄土坡耕地降雨产流产沙的影响

Influence of Intercropping Maize with Alfalfa on Runoff and Sediment Yield after Rainfall on Loess Slope Land

通过观测天然降雨时不同带宽玉米苜蓿间作下黄土坡耕地降雨产流产沙特征,研究了降雨条件一定时不同耕作模式对黄土坡耕地产流产沙量的影响和坡度变化对坡耕地产流产沙的影响。结果表明:在5°、10°、15°坡试验径流小区上①玉米单作年均产流总量分别比裸地降低了29.2%、15.8%和12.2%;苜蓿单作年均产流总量分别比裸地降低了78.5%、73.5%和75.0%;玉米苜蓿间作下年均产流总量分别比裸地降低了71.8%、59.7%和59.1%。②玉米单作年均产沙总量分别比裸地降低了39.0%、29.9%和22.0%;苜蓿单作年均产沙量分别比裸地降低了79.2%、84.5%和93.2%;玉米苜蓿间作下年均产沙量分别比裸地降低了74.0%、82.3%和89.5%。③各处理地块的产流产沙量随着坡度的增加而增加。各间作地小区,10°较5°的平均产流量多出81.1%,产沙量多出73.2%;15°较5°的平均产流量多出84.7%,产沙量多出81.3%;15°较10°的平均产流量多出19.0%,产沙量多出30.2%。

Through observing characteristics of runoff and sediment yield after rainfall on loess slope land under different strip width intercropping maize with alfalfa,the influence of different tillage modes and slope change on runoff and sediment yield under the same rainfall condition is studied in this paper.The results show that at the test runoff plot with the gradients of 5°,10° and 15°,firstly,compared with the bare soil treatment,the runoff yield at monoculture corn fields reduced by 29.2%,15.8% and 12.2%,respectively;that at monoculture alfalfa field reduced by 78.5%,73.5% and 75%,respectively;that at intercropping maize with alfalfa field reduced by 75.1%,58.9% and 51.3%,respectively.Secondly,the sediment yield at monoculture corn fields reduced by 39.0%,29.9% and 22.0%,respectively;that at monoculture alfalfa field reduced by 79.2%,84.5% and 93.2%,respectively;that at intercropping maize with alfalfa field reduced by 74.0%,82.3% and 89.5%,respectively.Thirdly,the amount of runoff and sediment yield increases with the increase of gradient for each treatment.In the intercropping plots,the plots with gradient of 10°have higher average runoff and sediment yield than plots with gradient of 5°by 81.1% and 73.2%,respectively.The plots with gradient of 15°have higher average runoff and sediment yield than plots with gradient of 5°by 84.7% and 81.3%,respectively.The plots with gradient of 15°have higher average runoff and sediment yield than plots with gradient of 10°by 19.0% and 30.2%,respectively.