In order to make an investigation on the effect of synchronously burying and returning straw and biogas slurry to the soil on straw decomposition,the research was conducted under normal condition at 20℃ by simulating burying and returning to soil by net bag method.In the 105 d experimental period,effects of biogas slurry produced by anaerobic fermentation of cattle manure or tape water on straw decomposition were systematically studied;influences of different soil types and different straw lengths on the decomposition rate of straw,the contents of cellulose,hemicelluloses,and lignin in straw decomposition after adding biogas slurry were also explored.The experimental results showed that biogas slurry could greatly accelerate straw decomposition.The straw decomposition rate in groups of tape water added was 33.61％,while that in groups of biogas slurry added was 42.37％.The straw decomposition mainly occurred in the first 70 d after adding biogas slurry.When the experiment was over,the straw decomposition rate of each experimental group was higher than 42％.The straw decomposition rate in the experimental groups of straw length being 20 mm was higher than that of being 10 mm.When the experiment was over,the straw decomposition rate in the experimental groups of straw length being 20 mm could reach 52％.Hemicelluloses decomposition could apparently be affected by straw lengths,and the shorter the straw length was,the quicker hemicelluloses decomposition was.However,cellulose and lignin decomposition could obviously be influenced by soil types.Compared with black loam soil,sandy loam soil was more active for the decomposition of cellulose and lignin in straw after its returning to soil.This research may lay a theoretical foundation for quick decomposition of straw in its returning to soil,as well as promote the widespread application of technique in straw returning to soil.%为探讨秸秆和沼肥同步翻埋还田对秸秆腐解的影响规律,在室温条件下,105 d试验周期内,采用网袋法模拟翻埋还田,系统研究添加沼肥和自来水对秸秆腐解的影响,以及添加沼肥后不同土壤类型和不同秸秆长度对秸秆腐解过程各主要参数的影响规律.结果表明,沼肥对秸秆腐解具有显著的促进作用,添加自来水组的秸秆降解率为33.61％,而添加沼肥组的秸秆降解率则达到42.37％;配施沼肥后,秸秆的降解主要集中在前70 d,试验结束时各试验组的秸秆降解率均高于42％,秸秆长度20 mm试验组的秸秆降解率高于10 mm秸秆,试验结束时20 mm试验组的秸秆降解率达到52％;秸秆长度对半纤维素的降解影响较明显,而土壤类型则对纤维素和木质素降解具有较显著的影响.
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