不同污泥施用方式下赤红壤坡地水土流失的特征

研究人工模拟降雨条件下,撒施、撒施+草和穴施3种污泥施用方式对赤红壤坡地水土流失的影响.结果表明,污泥施用后的前期(1和18 d)径流中,撒施、穴施与对照(不施污泥)间的径流量差异不明显,撒施颗粒物含量和流失量均达到峰值,分别为5387.7 mg.L-1和82.0 g.m-2,分别是对照和穴施对应峰值的1.1-2.0和1.2-2.0倍,此后撒施径流量、颗粒物含量和流失量均呈不同程度的降低趋势.模拟试验期间,撒施+草处理降低径流量,削减径流颗粒物和悬浮物流失的效果最为显著;撒施降低径流量和削减颗粒物流失的效果仅次于撒施+草处理,但撒施径流悬浮物流失最为严重;穴施径流量和颗粒物流失量是3种污泥施用方式中最高的,而悬浮物流失量则仅次于撒施.

Effects of sewage sludge application methods on soil and runoff losses from sloping plots on lateritic red soil

In order to prevent the loss of the contaminants of sewage sludge with runoff,the effects of application methods of sewage sludge on runoff and soil loss by erosion from sloping plots amended with sewage sludge on lateritic red soil were studied under simulated rainfall conditions.When the sludge was mixed with the surface soils for 1 day or 18 days,there were not significant differences in the runoff amounts among the broadcast application,hole-application and the control.However,the particulate concentrations and loss amounts in runoff from the broadcasted plots were highest among the three treatments,being 5387.7 mg·L-1 and 82.0 g·m-2,and 1.1-2.0,1.2-2.0 times of the corresponding peak values of the control and holeapplication,respectively.The runoff amounts,the concentrations and the particulate loss amounts of the broadcasted plots diminished gradually with time.During the whole experimental period,the most significant effects in reducing the runoff amounts,the loss amounts of particulate and total suspended solids were observed for the broadcasted plots with hay mulch.The runoff amounts and the particulate loss amounts were the lowest while the loss amount of total suspended solids was the highest from the broadcasted plots compared with the hole-applied and control plots.Among the three treatments,the amounts of runoff and the particulate loss were the highest from the hole-applied plots.The loss amounts of total suspended solids from the hole-applied plots were less than the broadcasted plots.