模拟降雨条件下草篱对坡地浅层土壤水分分布特征的影响  

Effect of Contour Grass Hedges on Water Distribution Characteristics in Shallow-layer Soil of Sloping Cropland Under Simulated Rainfall

作　　者：王庆海[1] 庞卓[1] 郑瑞伦[1] 李翠[1] 陈洁[1] 马雪菊 却晓娥 

机构地区：[1]北京市农林科学院北京草业与环境研究发展中心,北京100097 [2]中国林业科学研究院荒漠化研究所,北京100091

出　　处：《水土保持学报》2016年第4期110-115,122,共7页Journal of Soil and Water Conservation

基　　金：国家"十二五"科技支撑计划项目(2012BAD14B02)

摘　　要：为明确草篱对坡地浅层土壤水分分布特征的影响,在北京地区采用模拟降雨的方法,分层采集不同坡位的土壤样品,研究了在草木樨和狼尾草2种等高草篱措施干预下,不同雨强（30,45 mm/h）和坡度（15%,20%）条件下坡地降水迁移分配以及水分在浅层土壤中的分布特征。结果表明,该地区雨季坡地降水具有明显的沿坡面水平移动特征,无草篱对照地表径流量占降雨量的12%-44%。采用等高草篱能促进降水向下迁移,增加壤中流,减少30%-70%的地表径流,但此作用有随坡度的增加而减弱的趋势。浅层土壤含水量随土层加深而降低,表层（0-5cm）显著高于5-10,10-15cm土层。草篱带内土壤含水量与对应坡位无草篱区域的含水量处于同一水平。雨强、草篱、坡度均对坡地降水的运移和分配规律有显著影响,草篱的重要性高于坡度,低于雨强,是减少坡耕地降水流失的关键因素,但大强度的降雨和较陡的坡度会削弱草篱的水土保持功能。Grass hedges provided effective protection against soil and water loss in northern China. In this study, we evaluated the effect of 2 contour grass hedges, Melilotus albus and Pennisetum alopecuroides, on distribution characteristic of soil water in sloping cropland. The experiments were carried out on corn （Zea mays L. ） field with slope gradients of 15% and 20% under simulated rainfall （rainfall intensity of 30 mm/h and 45 mm/h） in the Changping District of Beijing, China. Soil samples were collected from 2 slope positions （middle slope and slope bottom） at 3 soil depths （0--5 cm, 5--10 cm and 10--15 cm）. The results indicated that the obvious horizontal migration of precipitation along the slope was observed after rainfall events in sloping cropland, and runoff of treatments without grass hedges accounted for 12% to 44% of total rainfall in the study area. Grass hedges accelerated the vertical migration of precipitation and increased the subsurface flow, consequently reducing surface runoff by 30% to 70% and resulting in significant reduction of water loss. But the reduction extent was weakened with the increase of slope gradient. Shallow-layer soil water content decreased with increasing soil depth, and it in topsoil （0-5 cm） was markedly higher than that in 5--10 cm and 10--15 cm soil layer. Soil water content had no significant differences between soils at the same slope position with and without the hedgerows. Rainfall intensity, grass hedge and slope gradient.

关 键 词：草篱 土壤水分 分布特征 坡耕地 

分 类 号：S157.43[农业科学—土壤学]