Study on soil moisture content under artificial vegetation in Changwu of Xianyang county in spring

According to soil moisture content determination of apple forest land and wheat field at Changwu County in Xianyang in spring,the change of 0～6 m soil moisture content and its influence on water cycling were studied in this paper.The result shows that the soil moisture content in 6m soil profile under apple forest land is high in the upper layer and becomes low in the middle and then becomes high in the lower layer.The main moisture-consumed layer is 100～310 cm.The soil moisture content in 6 m soil profile under wheat field is low in the upper layer and increases in the middle and lower layer.The main moisture-consumed layer is 0～120 cm.The mean soil moisture content under wheat field is 3%～4% higher than that under apple forest land generally.The middle and lower layer is higher while the upper layer is lower.The research result indicates that,dried soil layer hasn′t developed in wheat field in spring,while in 130～310 cm earth layer under apple forest land distributes thin dried soil layer developed faintly.If the annual rainfall shouldn′t reach 600 mm continually,dried soil layer would develop widely.The development of dried soil layer under apple forest land cuts off rainfall′s infiltration through deep-layer partially and rainfall can′t replenish groundwater normally,which affects normal water cycling in this region.In order to keep the growth of apple forest and the transfer of soil moister normally,severe dried soil layer should be avoided and planting density should be controlled strictly.