为了探讨聚丙烯酰胺对防治北方农牧交错带草场沙化的效果，通过野外小区对比试验和室内分析，采用二因素完全随机设计，研究了在不同植被条件下施用不同剂量聚丙烯酰胺后土壤颗粒组成的变化。结果表明：在30~120kg/hm2的剂量范围内，聚丙烯酰胺能够有效地促进土壤砂粒（2~0.02mm）含量的减少和黏粉粒（<0.02mm）含量的增加，使土壤粗砾化现象得到明显改善。其中尤以30kg/hm2水平的聚丙烯酰胺剂量效果最为明显，砂粒含量的降低幅度比对照提高了6.95~11.29个百分点，黏粉粒含量的增加幅度比对照提高了6.91~12.54个百分点。

For discussing the prohibition effect of polyacrylamide (PAM) on grassland desertification in farming-pastoral ecotones in the north of China, through field plot compared experiment and indoor analysis, it studied the effect of different dose polyacrylamide (PAM) on soil particle composition by two factors complete randomization design. The results showed that PAM within 30～120kg/hm2 accelerated the reduction of sandy particle (2～0.02mm ) content and the increasing of clay-silt particle(<0.02mm) content , improved the coarsening of soil. The best effect was 30 kg/hm2 of PAM applying, the reduction range of sandy particle content was improved 6.95~11.29 percentages and the increasing range of clay particle was improved 6.91~12.54 percentages compared with control.