等高植物篱控制紫色土坡耕地侵蚀的特点

应用等高植物篱能在较低投入下有效控制坡地土壤侵蚀和养分流失。三峡库区紫色土 2 5°坡地的大雨强模拟降雨实验表明 ,香根草等高植物篱能减少相当于对照坡耕地的 82 .2 %的侵蚀量 ( 1 997年 1 1月 ) ,通过施肥促进植物篱生长密闭能进一步提高对流失土壤的拦截效率 ,效果不逊于带间覆盖。经过 31个月的侵蚀过程 ,各植物篱小区最明显的坡形变化是篱带处及其前部堆淤成接近水平的淤积带。由于植物篱的阻滞和坡形的变缓 ,径流和表土作用的时间延长 ,由径流携带的养分损失成为坡面养分流失的重要途径 ,控制径流损失是控制养分流失的重要方式之一 ,同时也有助于减少坡面侵蚀

CHARACTERISTICS OF EROSION CONTROL BY CONTOUR HEDGEROWS ON CULTIVATED SLOPE LAND OF PURPLISH SOIL

Growing contour hedgerows on slopelands is an effective way to control soil erosion and nutrient loss.The experimental data of simulated rainfalls on a slope land(25°)of purplish soil in the Three-Gorge-Reservoir Region indicated that the Vetiveria zizanioides contour hedgerow plots decreased 82.2% in soil loss as compared with the cultivated plot.Fertilization did good to the growth of hedgerows and hence the effect of erosion control;which was comparable to the mulching treatment.The most distinct variation in slope shape between hedgerows was the formation nearly alluvial strips.With changing slope shape and increasing interception by hedgerows,the interacting time between soil and runoff was prolonged.As nutrient loss in runoffs,is an important way,hedgerows' function of controling runoff loss is helpful in decreasing soil erosion and nutrient loss by hedgerows.