【摘要】 【目的】碳氮化学计量不仅调控秸秆腐解速率，而且还影响秸秆-土壤微生物-作物之间的氮竞争关系，是影响秸秆还田培土增产效应的关键因素。以我国西北荒漠绿洲氨化秸秆还田系统为研究对象，分析了不同氮素分配下秸秆-土壤-作物系统的碳氮化学计量关系及其增产效应。【方法】试验设置5个氮素分配处理，各处理总施氮量一致（300 kg/hm²），一部分用于氨化秸秆，其余部分田间撒施。用于氨化秸秆的氮投入量依次为0（SN₀）、40(SN₄₀)、80(SN₈₀)、120(SN₁₂₀)和160(SN₁₆₀)kg/hm²。【结果】秸秆氨化后碳氮比下降使土壤碳氮比上升，从而降低了叶片碳氮比，最终提高了作物的产量。相比秸秆直接还田，氨化秸秆还田一方面维持了春玉米灌浆期适宜的土壤碳氮比（5.3～6.0），另一方面避免了过高（>30）的玉米叶片碳氮比，协调了植株源汇器官的碳氮关系并将玉米产量提高了17.9%以上。在所有处理中，SN₁₆₀处理不仅获得了最高的籽粒产量，还最大程度地提高了土壤有机碳和氮素含量。【结论】建议在新垦绿洲农田按照SN₁₆₀处理（秸秆氨化用氮160 kg/hm²，土壤施氮140 kg/hm²）进行氨化秸秆还田，可实现在不增加氮肥用量的前提下增加玉米产量。更多还原

【Abstract】 【Objective】Carbon and nitrogen stoichiometry not only regulates the rate at which straw decomposes after being returned to the field,but also affects the nitrogen competition between the microorganisms in the soil,the straw and the crops,which is a key factor in increasing the yield when straw is returned to the field. This study examined the ammoniated straw return system in the desert oasis of northwestern China,analyzing the carbon and nitrogen stoichiometric relationship and yield increase effect of the soilstraw-crop system under different nitrogen distributions.【Method】The experiment involved five nitrogen distribution treatments,each with a total nitrogen application rate of 300 kg/hm². One of these treatments involved ammoniating straw,while the rest were applied to the field. The nitrogen input for the ammoniated straw was 0（SN₀）,40(SN₄₀),80(SN₈₀),120(SN₁₂₀) and 160(SN₁₆₀) kg/hm²,respectively.【Result】A decrease in the carbon-to-nitrogen ratio of straw following ammonia treatment results in an increase in the soil’s carbon-to-nitrogen ratio. This reduces the carbon-to-nitrogen ratio of leaves and ultimately enhances crop yield. Compared with the direct incorporation of straw,the incorporation of ammonia-treated straw not only maintains an appropriate soil carbon-to-nitrogen ratio（5. 3～6. 0） during the filling stage of spring maize,but also avoids an excessively high（≥30） carbon-to-nitrogen ratio in maize leaves. This coordinates the carbon and nitrogen relations between the source and sink organs of the plant,thereby increasing maize yield by more than 17. 9%. Of all the treatments,SN₁₆₀ achieved the highest grain yield and maximized soil organic carbon and nitrogen content.【Conclusion】According to SN₁₆₀ treatment（160 kg N/hm² for ammoniating the straw and 140 kg N/hm² for soil application）,it is suggested that returning ammoniated straw to newly reclaimed oasis farmland can increase maize yield without the need to increase the amount of nitrogen fertilizer.更多还原