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在大田条件下,研究了水稻秸秆还田和施氮量对晚播小麦产量、养分积累、秸秆养分释放及养分平衡的影响.结果表明:水稻秸秆还田并配施适当的施氮量有利于提高晚播小麦籽粒产量.晚播小麦全生育期的干物质、氮、磷、钾积累量均随施氮量增加而显著增加,相同施氮量(270 kg N·hm-2)下,秸秆还田处理的干物质、磷、钾积累高于不还田处理,氮积累则呈相反趋势.随着施氮量增加,秸秆腐解和养分释放率增加,且拔节后秸秆养分释放量占总释放量的比例降低;随生育进程的推进,秸秆的干物质、磷、钾释放量呈倒“N”型变化趋势,而氮释放量则呈“V”型变化趋势.计算养分表观平衡结果表明,秸秆还田并增加施氮量,养分总盈余量显著升高;在获得较高产量的施氮条件下,氮、钾素显著盈余,磷素投入较为合理.晚播小麦实行秸秆还田后,可适当增加氮肥用量至257 kg·hm-2,并减少钾肥投入.
Under field conditions, the effects of rice straw returning and nitrogen application on yield, nutrient accumulation, nutrient release and nutrient balance of late sowing wheat were studied. The results showed that straw addition to rice with suitable amount of nitrogen was beneficial Increase the grain yield of late-sowing wheat.The accumulation of dry matter, nitrogen, phosphorus and potassium of late-sowing wheat all increased significantly with the increase of N application rate. Under the same nitrogen application rate (270 kg N · hm-2) The accumulation of dry matter, phosphorus and potassium in the field was higher than that of the non-treatment and the accumulation of nitrogen showed the opposite trend.With the increase of nitrogen application, the decomposition of straw and nutrient release rate increased, and the amount of straw nutrient released after jointing With the advance of the fertility process, the dry matter, phosphorus and potassium release of straw showed a tendency of “N”, while the amount of nitrogen released showed a tendency of “V” Apparent balance results showed that straw returning to field and increasing N application rate increased the total nutrient surplus significantly. Under the condition of higher N application, N and K were significantly surplus and P input was more reasonable. Late-sowing wheat After the implementation of straw returning, nitrogen fertilizer can be appropriately increased to 257 kg · hm-2, and reduce Potash investment.