PAM对沙质土壤持水性能影响的模拟研究

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

通过试验模拟，研究了不同剂量聚丙烯酰胺（PAM）施入沙质土壤后对土壤持水性能的影响．PAM设置0（对照），50，100，200，400和1000mg／kg6个水平．实验结果表明，与对照相比，经PAM处理后的土壤累积蒸发量减小了4．12％～14．46％；平均含水量增加了1．40％～5．64％；田间持水量增加20．68％～33．71％，毛细管持水量增加18．41％～29．04％，最大持水量增加18．62％～29．70％；方差分析在5％水平上各处理间存在显著差异，最大差异出现在PAM施加量为200mg／kg时．表明了PAM能够改善土壤的持水性能，其改良效果因PAM施入浓度而异．在改良该沙壤土保水性时，其适宜PAM施用量为200mg／kg．

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.