秸秆还田方式与施氮量对春玉米产量及干物质和氮素积累、转运的影响

【目的】探讨秸秆还田方式与施氮量对东北春玉米产量、干物质和氮素积累、转运的影响，明确适宜的秸秆还田方式及施氮量。【方法】连续两年在辽宁铁岭市进行了田间试验。设置秸秆还田方式 (旋耕、翻耕) 与施氮量两因素田间定位试验，研究了春玉米产量及干物质和氮素积累、转运特性。【结果】秸秆旋耕和翻耕还田产量和籽粒氮素积累量差异并不显著，但前者显著增加了地上部干物质和氮素积累量，及花后氮素积累量、花后干物质积累对籽粒干物质积累贡献率、花后氮素积累对籽粒氮素积累贡献率，而后者则显著提高了花前营养器官干物质、氮素转运量和转运率，花前营养器官干物质和氮素转运对籽粒干物质和氮素积累贡献率分别达到了12.4%、44.1%。随着施氮量的增加，产量和籽粒氮素积累量，地上部干物质和氮素积累量呈逐渐增大的趋势。但施氮量超过262.5 kg/hm2后，产量和籽粒氮素积累量差异则不显著。施氮量262.5 kg/hm2时，花前营养器官干物质和氮素转运量和转运率最高，花前营养器官干物质和氮素转运对籽粒干物质和氮素积累贡献率分别达到了16.7%、45.2%。【结论】短期秸秆旋耕和翻耕还田，春玉米产量和籽粒氮素积累量差异不显著，然而秸秆旋耕还田作业成本较低，且配施262.5 kg/hm2氮产量较高，可作为秸秆还田初期推荐施氮量。

Effects of straw management and nitrogen application on spring maize yield,dry matter and nitrogen accumulation and transfer

【Objectives】Nitrogen application and total straw incorporation affect spring maize yield, dry matter and nitrogen accumulation and transfer. The proper combination mode of N and straw returning was studied in this paper.【Methods】A two factors field experiment was conducted consecutively for two years in Tieling City, Liaoning Province. Two straw incorporation modes (rotary tillage and moldboard plow tillage) and five nitrogen application levels were designed. Spring maize yield, dry matter and nitrogen accumulation and transfer were analyzed.【Results】Compared with the moldboard plow tillage of straw incorporation, the dry matter, N accumulation were increased in the rotary tillage straw incorporation treatment, while there was no difference in the yield and grain nitrogen accumulation under the two straw incorporation treatments. The accumulation and contribution of dry matter and N to grain efficiency were increased in the rotary tillage straw incorporation treatment. The dry matter and N transfer, dry matter and N transfer efficiency were increased in the moldboard plow tillage straw incorporation treatment, and the contribution of dry matter and N transfer to grain efficiency pre-anthesis were 12.4% and 44.1%. With the increase of N application rate, the yield, grain nitrogen accumulation, dry matter and N accumulation were increased. No significant increase in yield and grain nitrogen accumulation was found when the nitrogen application rate was higher than 262.5 kg/hm2. The highest dry matter and N transfer, dry matter and N transfer efficiency were obtained in the nitrogen application rate of 262.5 kg/hm2, and the contribution of dry matter and N transfer to grain efficiency were 16.7% and 45.2%, respectively.【Conclusions】In this study, the two straw incorporation modes had similar yield and grain nitrogen accumulation, but the rotary tillage straw incorporation treatment could reduce the cost of soil tillage and greatly improve economic benefit, and the straw incorporation with nitrogen application rate of 262.5 kg/hm2 was the optimal mode.