Effects of PAA on Soil Preserving Water and Evaporation

In order to clarify the effect of water conservation of PAA on main soil,such as Lou soil,Loessal soil and Dark loessial soil,of loess plateau,a method of soil column was used to measure soil water retaining capability,soil saturated hydraulic conductivity and evaporation capacity in three kind of soil of loess plateau by labtest.The results indicate that soil moisture was increased after applying PAA to field.When the PAA was not applied,the capability of preserving water of dark Loessial soil was lowest,that of Lou soil is highest,and that of Loessal soil is middle.After applying the PAA,the capability of preserving water of Dark loessial soil increased significantly,almost two times compared with CK,and that of Lou soil and loessal soil were higher than CK.Soil water-supplying capability enhanced with the increase of PAA.Between the 3 soils,the soil water-supplying capability showed Lou soilDark loessial soilLoessal soil.When the PAA was not applying,the soil saturated hydraulic conductivity indicated Lou soilDark loessial soilLoessal soil.However,the saturated hydraulic conductivity of 3 soils reduced with the increase of it when the PAA was applied.Under the soil moisture,soil anti-evaporation enhanced when the PAA was utilizing,and evaporation of Lou soil and Dark loessial soil improved with the increase of PAA,but lower than CK.Evaporation of Loessal soil decreased with the increase of PAA.For example,the evaporation of three soils(Lou soil: PAA54.5 mg/kg,Dark loessial soil and loessal soil:225.8 mg/kg) reduced respectively by 40.0%,44.6%,and 30.6% compared with CK.