聚丙烯酰胺对磷素在土壤中吸附-解吸的影响

聚丙烯酰胺（PAM）在农业上作为扰侵蚀剂、保水剂被广泛应用，但施用后对土壤养分保持和释放的影响研究较少。本文采用向土壤（塿土）中添加不同比例（0．1％，0．2％，0．4％占土壤的比例）的PAM溶液，通过磷素等温吸附解吸试验，探讨了PAM对磷素在土壤中吸附和解吸的影响。结果表明。和原土样相比．土壤经PAM处理后抑制了土壤对磷的物理吸附，导致吸附量减小．最大吸附量（Xm）降低，而对磷素在土壤中的化学吸附影响较小．被吸附磷尤其是物理吸附磷的解吸率升高。

Effect on PAM on Phosphorus Adsorption and Desorption in Lou Soil

Polyacrylamide is widely used as soil conditioner to improve soil capacity for water retention and anti-erosion,while its impact on soil nutrients' retention and release is not clear.In this paper,Lou soil was amended with PAM at varied ratios of 0.1%,0.2% and 0.4%,and technique of phosphorus isotherm absorption and desorption was employed to study the effect of PAM on phosphorus retention and release in Lou soil.The results showed that PAM amended with soil can prohibit the physical absorption of phosphorus and led to decrease of absorption amount and maximum adsorption amount(X_m),but the effect PAM on phosphorus chemical absorption is small.Soil amended with PAM increase the release of absorbed phosphorus,especially for the physical absorbed phosphorus.