The objective of this research was to discover the formation mechanism of wheat production through study the impact of straw-return and fertilizer-N application on grain yield, yield components and nutrient absorption of winter wheat, and soil nutrient availability in Huang-huai-hai plain's cropland. The results showed that under the same fertilization conditions, the way of straw-return had the trend of increasing the production of winter wheat, but the effect was only significant in the fertilizer-N application of 150 and 200 kg/hm2; Generally, straw-return can raise the production by the rate of 6.34%-12.17%. It was mainly because straw-return increased 1000-kemel weight; and it may be also related to the reason that straw-return increased the aboveground nitrogen absorption of winter wheat in the time of jointing-heading. Meanwhile, straw-return with nitrogen fertilizer increased the contents of soil alkali-hydro nitrogen and rapidly-available potassium, which provided fertility foundation for crop nutrient uptake. Compared with no nitrogen fertilizer, rising grain yield by application of fertilizer mainly was due to the increase of panicles per unit area, but grain productions under the different applications of nitrogen fertilizer had no significant difference, which indicated that the local conventional application of nitrogen fertilizer was in part a potential way of saving fertilizer.%通过田间试验,比较研究了秸秆还田和不还田条件下氮肥施用量对我国黄淮海平原典型农区冬小麦籽粒产量、产量构成因素、养分吸收过程及土壤速效养分的影响,目的是为了挖掘不同耦含条件下的小麦产量形成机理.结果表明相同施肥条件下,秸秆还田有增加冬小麦籽粒产量的趋势,但只有在施氮量为150和200 kg/hm2时,其差异达显著水平；当不施肥或施氮量为250 kg/hm2时,差异不显著,总体来说,秸秆还田的增产率为6.34％～ 12.17％,这可能主要由于秸秆还田提高了籽粒千粒重所致,也可能与秸秆还田增加了冬小麦拔节-抽穗期地上部生物量氮素吸收量有关.同时,秸秆还田配施氮肥还提高了土壤碱解氮和速效钾含量,为作物养分吸收提供了肥力基础.与不施肥相比,单纯施肥导致的籽粒产量增加主要由于增加单位面积小麦穗数所致,但不同施肥量之间籽粒产量没有显著性差异,表明当地常规施肥习惯有一定节肥潜力.
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