Effects of PAM on soil retention water

The organic high polymer has an important effect on the characteristics of soil water.In order to clarify the effect of water conservation of polyacrylamide(PAM)(0 mg/kg,54.5 mg/kg,112.9 mg/kg,169.4 mg/kg,225.8 mg/kg) on main soil of Loess Plateau,such as Lou soil,Loessal soil and Dark loessial soil,a method of soil column was used to measure soil water retaining capability,soil saturated hydraulic conductivity and evaporation capacity in three kinds of loess plateau soils by lab test.The result indicated that soil water retaining capability of Dark loessial soil and Loessal soil were higher than CK under the action of PAM,but that of Lou soil did not show evident change.However,with the increasing of PAM,the saturated hydraulic conductivity of Loessal soil increased except under treatment 4(225.8 mg/kg),that of Dark loessial soil advanced a little except under treatment 4(225.8 mg/kg),but that of Lou soil was inverse.As for anti-evaporation of soil water,soil evaporation reduced with the increasing of PAM,for example compared with CK,the evaporation under treatment 4(225.8 mg/kg) of three soils reduced respectively by 24.5%,55.8%,and 33.7%.Above study showed PAM improved water retaining capability of soil and hydraulic conductivity during relative PAM dosage,and decreased soil evaporation.