秸秆-膨润土-PAM改良材料对不同类型土壤中腐殖质含量的影响

土壤有机质是土壤肥力的重要因素，土壤腐殖质是土壤有机质的主体，为了提高土壤腐殖质含量，将秸秆、膨润土和聚丙烯酰胺(PAM)按不同配比配制作为改良材料，研究改良材料配比、时间等因素对四川省宜宾市3种类型土壤腐殖质含量的影响。结果表明，添加秸秆改良材料后，土壤腐殖质含量相比对照处理有显著提高，且随膨润土和PAM施用量的增加，对土壤腐殖质含量的改善效果更好。随着改良材料施入时间的延长，冲积土和灰棕紫泥腐殖质含量在前3个月先减小，后3个月趋于稳定；而暗紫红泥的腐殖质含量在前3个月先增加，后3个月呈现下降趋势，但比2009年12月土壤腐殖质含量高。可见，改良材料的施入，能有效的防止土壤腐殖质的流失。

Effects of Straw-Bentonite-PAM Improved Materials on the Humus Content of Different Soil

Soil organic matter is an important factor of soil fertility, soil humus is the main body of soil organic matter. In order to improve the content of soil humus, the improved materials which confected by crop straw, bentonite and polyacrylamide (PAM) were applied with different proportions and the effects of portion and time on soil humus content was studied for 3 soil types in Yibin, Sichuan Province. The results showed that after the application of the improved materials, compared to CK, soil humus content increased with the increase of bentonite and PAM. The contents of humus in atteration and grey brown purple soil decreased in the first three months, and then kept stable for the next three months. The content of humus in dark purple clay showed an increasing trend in the first three months, and then decreased for the next three months, but it was still higher than that in December 2009. Thus, the application of improved materials could prevent the loss of soil humus effectively.