A Simulated Study of the Effect of PAM on Water Holding Capacity of Sandy Soils

In a simulated experiment,sandy yellow soil was supplemented with polyacrylamide(PAM) at 0,50,100,200,400 and 1000mg/kg to evaluate its effect on water-holding capacity of the soil.The results indicated that PAM restrained the evaporation of soil moisture.Compared with the control treatment(CK),PAM treatments decreased the evaporation capacity of soil moisture by 4.12%~14.46% and increased the average water contents of the soil by 1.40%~5.64%,field capacity by 20.68%~33.71%,capillary capacity by 18.41%~29.04% and maximum water-holding capacity by 18.62%~29.70%.Analysis of variance showed that significant differences existed among the treatments,indicating that the effect of PAM application varied with its rate.Under the conditions of the experiment,the treatment of 200 mg/kg PAM gave the best result of restraining soil moisture evaporation.