中文摘要：

采用室内培养方法研究了水稻秸秆腐解对土壤溶解性有机质（Dissolved Organic Matter,DOM）含量及其化学组成的动态影响。结果表明,秸秆腐解的前7 d显著增加了土壤溶解性有机碳（DOC）含量,7 d后则无明显影响;同时,秸秆腐解增加了土壤中溶解性糖（DS）、溶解性酚酸（DP）以及芳香族化合物含量。随着腐解时间的延长,溶解性糖在DOC中所占比例下降,而芳香族化合物逐渐上升,表明秸秆腐解不同阶段DOM的化学组成发生了变化。溶解性总氮（TDN）的变化表明,秸秆腐解增加土壤氮素的固定。

英文摘要：

A laboratory incubation experiment was carried out to investigate the dynamic effect of the decomposition of rice straw in three paddy soils on dissolved organic matter（DOM） and its chemical fraction including dissolved sugars （DS）, dissolved phenols acids（DP） and aromatic compounds. The results showed that the content of DOC increased significantly in the first 7 days of incubation, then no significant changes was observed. Decomposition of rice straw increased DS and DP in the soils. As straw decomposition continued, the percent of DS to DOC decreased while aromatic compounds increased. This suggested that the chemical composition of DOC changed during the period of incubation. The dynamic changes of total dissolved nitrogen（TDN）showed that the decomposition of rice straw induced N immobilization in the soils.