覆膜对有机物料的腐解及土壤有机质特性的影响

EFFECTS OF COVERING WITH PLASTIC FILM ON DECOMPOSITION OF ORGANIC MATERIALS AND CHARACTERISTICS OF SOIL ORGANIC MATTER

砂滤管长期培养试验结果表明,有机物料和农肥施入土壤后,腐解残留率(Yt)与有机物料施入后的时间(t)遵循Yt=Y^(A t)_(oe)方程式,式中Yo为有机物料缓分解成分的碳理占加入总碳量的百分数,λ为缓解成分的分解速率。覆膜使Yt和Yo值明显降低。田间试验结果表明,覆膜降低了有机质的活性,使PQ值(胡敏酸占可提取腐殖酸的百分数)和A2/A3比值(胡敏酸在波长200nm和300nm处吸光度之比)增高,胡敏酸对光吸收增强。

This paper deals with the decomposition patterns of organic .naterials after addition to soils covered with plastic film during 1985 - 1993 at liaoning province. The characteristics of soil organic matter in covering soils were also studied compared with those of uncovered soils. The results obtained from the long-term experiment with carborundum tubes showed that remaining orgainc matter (Yt) of different organic materials after addition to soils and time (t>one year) fitted into the equation Yt-Yoe, where Yo means percentage of resistant organic C in total C applied, X is decompositiom rate of resistant organic matter. Nearly all correspoding Yo and Yt decreased in soils covered with plastic film. In addition, the results from the field experiment showed that the relative contents (%) of active organic C in total orgamic C declined, whereas PQ values(the percentage of humic acids in extractive humus) and A2 /A3 ratio (absorhance ratio of humic acid at 200nm and 300nm) as well as the absorbance of humic acids in the wave length of 726~400nm increased respectively.