东北北部不同埋深玉米秸秆腐解进程及效应的研究

Research on Decomposition Process and Effect of Different Buried Depth of Maize Straw in North of Northeastern China

东北北部年均气温低且低温天气持续时间较长,致使还田玉米秸秆当季难以腐解。本研究通过探讨不同埋深玉米秸秆腐解规律与效应,以期为东北北部合理选择玉米秸秆还田方式提供理论基础和科学依据。试验基于玉米秸秆不同还田方式定位试验,采用尼龙网袋法,于常规垄作模式中设置0、15、30 cm 3个秸秆埋深处理,研究不同埋深玉米秸秆腐解进程及腐解过程中不同埋深土壤碳、氮含量和相关酶活性的变化规律。结果表明:10~20 cm、20~30 cm和0~10 cm埋深玉米秸秆当季腐解率分别达81.89%、75.64%和60.67%,碎混还田>翻埋还田>地表覆盖还田模式玉米秸秆当季腐解率分别达84.92%、77.54%和65.26%;生育期内10~20 cm埋深土壤水热条件为最佳,土壤碳、氮素含量均较高,土壤酶活性亦较强,益于加快还田秸秆的有效腐解。

The annual average temperature in north of northeastern China is lower and the low-temperature weather lasts for a long time,which makes it difficult for the returned maize straw to decompose in the season.Decomposition Process and effect of different buried depth of maize straw were explored to provide theoretical foundation and scientific basis for suitable way selection of maize straw returned in north of northeast China.The study based on location test of different maize straw returning approaches,maize straw buried in the 0,15,30 cm depth were set in traditional ridge pattern using the method of nylon mesh bags.The decomposing process of maize straw in different buried depth and changing rules of content of soil carbon,nitrogen and activities of related enzyme were studied during the maize straw decomposing.The results showed that the decomposition rate of maize straw of 10-20 cm,20-30 cm and 0-10 cm buried depth were 81.89%,75.64%and 60.67%,respectively in the current season,and the decomposition rate of maize straw of different straw returned pattern were 84.92%,77.54%and 65.26%,respectively in the current season;conditions of soil water and heat of 10-20 cm buried depth was the best in the growth period,and content of soil carbon and nitrogen content were both higher,activities of soil enzyme was also stronger,which was benefit for accelerating the effective decomposition of returning straw.