Infiltration Performance of Different Land Use in Loess Hilly Region

It takes undisturbed samples from three levels of top soil,subsoil and check soil of three types of land use of terraced field,orchard and dammed land by using PVC tube.It tests the infiltration performance of soil by using non-pressure water supply and infiltration device in laboratory.It conducts continuous tracking observation of the infiltration performance of each sample and takes steady outflow from the bottom of soil columns as steady infiltration rate of the depth of soil layer.The study outcomes show that a) the infiltration performance of different land use is greatly different and the infiltration performance for different soil depth of the same land use is also obviously different;b) the infiltration capacity of undisturbed soil is greater than that of disturbed soil and the structure and capability of infiltration of top soil is better than that of subsoil;c) the test with undisturbed soil can truly show the infiltration performance of soil.Introducing infiltration rate into the concept of depth determination,presenting the spatial variation on vertical scale and the affecting factor of soil more accurately,it will have important guiding values to study on soil infiltration and improve the theory of soil infiltration.