The Comparing Study on Soil Infiltration of Vegetation Land in Hilly Area of Loess Plateau

The original soil was got by PVC tube in Robinia peudoacacia,Hippophae rhamnoides,and grassland three forest vegetations,soil depth includes 0～30 cm,30～60 cm,0～60 cm.Put the original soil in the room,the special supply water device was used to determinate soil infiltration,which haven't splash erosion and pressure head.Processes of Infiltration about all soil columns are tracked continuously;the steady infiltration rate is represented by steady outflow from the bottom of soil columns.At the same time,it proposed that the steady infiltration rate should be defined by the soil depth,and also proposed the influence of infiltration choke points on a given soil depth.The results showed that the capability of original soil infiltration is greater than disturbed soil;diversity of infiltration is great in different forest types,which is also significant in the same forest types but different soil depth;the capability of original soil infiltration on top soil is greater than bottom soil,and so on.