【摘要】 为了阐明棕壤有机氮组分(活性和惰性)对秸秆不同还田方式和数量响应的差异及机理,为棕壤肥力提升及作物增产提供科学依据。试验在沈阳农业大学棕壤长期定位试验站内采用大田小区试验进行,包括玉米秸秆半量和全量还田、直接和腐熟还田处理,研究了春玉米拔节期、抽雄期、灌浆期和成熟期棕壤全氮的含量及有机氮活性和惰性指数的动态变化状况。结果表明:(1)在试验条件下,秸秆还田有利于增加棕壤全氮的含量,增加的幅度范围为6.74%～32.89%,且秸秆腐熟全量还田与化肥配施处理对棕壤全氮含量的增加效果较其他处理更加显著,增加的幅度为32.89%,更有利培肥地力和促进棕壤氮素的积累;(2)秸秆还田有利于提高棕壤有机氮活性指数,提高的幅度范围为4.70%～25.15%,且腐熟秸秆半量还田处理提高的效果优于其他处理,提高的幅度为25.15%,更有利于增加棕壤活性有机氮组分在土壤全氮中的占比,更有利于作物的生长发育;(3)单施化肥处理棕壤有机氮含量虽然可以保持稳定或者略有增加,但是会导致棕壤有机氮惰性指数降低,降低的幅度为4.73%。更多还原

【Abstract】 The effects of ways of straw returning on organic nitrogen(N) components(activity and inert) were investigated in order to reveal the mechanism of organic N sequestration and to provide scientific basis for soil fertility improvement and crop yield increasing in Brown Earth. The maize straw(decomposed or fresh) was semi-and fullreturned in the long-term experiment station of Brown Earth, Shenyang Agricultural University. We analyzed the dynamic change of total N content, and organic N active and inert indices during maize jointing, tasseling, grouting and ripening stages. The straw returning increased the content of total N by 6.74%-32.89%. Especially in the treatment of decomposed straw full returning combined with fertilization, the content of total N was increased by about 32.89%,which was more favorable to promote soil fertility and N accumulation in Brown Earth. Organic N activity index was enhanced by 4.70%-25.15% after straw returning. And it was 25.15% larger in the treatment of the decomposed straw semi returning than in the other treatments, which led to the increase in the proportion of active organic N component in total N of Brown Earth and was more conducive to the growth and development of the crops. The organic N content remained stable or increased slightly, while the organic N inert index was decreased by 4.73% in the single fertilizer application in Brown Earth.更多还原