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在大田条件下,研究了不同施氮量对秸秆还田下晚播小麦土壤矿质氮含量变化、秸秆氮释放及小麦产量的影响.结果表明:0~50 cm土层土壤矿质氮含量随着施氮量的增加而显著增加,随生育进程的推进,N270和N360处理下层土壤的矿质氮显著积累.秸秆氮素释放量随施氮量增加而增加,越冬至拔节期氮释放量最低,拔节至成熟期释放量占总释氮量的50%以上.全生育期施氮量超过180 kg·hm-2,土壤氮素开始出现显著的盈余,播种至拔节期氮素表观盈余量显著高于拔节至成熟期.籽粒产量在270 kg·hm-2施氮量下最高,更高施氮量下氮素利用效率显著降低.施氮量为270 kg·hm-2时,有利于秸秆全量还田下晚播小麦兼顾产量和生态效益.
Under field conditions, the effects of different nitrogen application rates on the change of mineral nitrogen, nitrogen release from straw and wheat yield under late sowing of wheat straw were studied.The results showed that the mineral nitrogen content in 0 ~ With the growth of fertility increasing, the mineral nitrogen in the lower layer of N270 and N360 significantly increased, while the nitrogen release of straw increased with the increase of nitrogen application, the lowest in nitrogen release from wintering to jointing stage, At mature stage, the amount of nitrogen release accounted for more than 50% of the total nitrogen release.Nitrogen content in the whole growth period exceeded 180 kg · hm-2 and soil nitrogen began to show a significant surplus, and the apparent nitrogen surplus at sowing to jointing stage was significantly higher than The grain yield was the highest under the nitrogen application rate of 270 kg · hm-2, while the nitrogen use efficiency decreased significantly under the higher nitrogen application rate. When the nitrogen application rate was 270 kg · hm-2, Field evening broadcast wheat balance both yield and ecological benefits.