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在1985～1986年和1986～1987年两个具有不同气候特点的年份，于Rothamsted试验站进行了多因素试验，研究了在冬前和春后小麦重要生长发育阶段施N对9月播种和10月播种的冬小麦产量和籽粒含N量的影响。改变冬前N素供应的处理是在冬前给小麦施用N肥和把小麦种植在具有不同土壤N素残留量的油菜茬地和燕麦茬地上。春后施N在总量为200kg／ha的施肥水平上，设置早施或迟施，一次性施用或分次施用等处理组合。1985～1986年的试验还研究了在夏季增施50kgN/ha的作用。在两年的试验中，9月份播种比10月份播种的小麦产量高。与1985～1986年比较，1986～1987年9月播种的小麦越冬阶段生长较好，但在植株生长和N素吸收方面的早期优势只提高了秸秆产量而未增加籽粒产量。两年中，燕麦茬土壤氮素的残留量都低于油菜茬。土壤氮素的差异不影响10月播种的小麦越冬期生长和氮素吸收。1985～1986年，因不良的气候条件限制了小麦冬前生长和氮素吸收，无论是冬前施N还是土壤残留N含量都未影响9月播种的小麦产量。而在1986～1987年，燕麦茬小麦的产量比油菜茬减产420kg／ha，但是这种减产可以通过施用氮肥以平衡土壤含N量来消除。在4月份一次性推迟施N使小麦减产，特别是在9月播种的燕麦茬小麦和冬前未施N肥的处理，而其余的春后N
In 1985-1986 and 1986-1987, two climatic characteristics of different years, the Rothamsted experimental station conducted a multi-factor test to study the important winter wheat and winter wheat growth and development stages of N seeding and September 10 Effect of monthly sowing date on winter wheat yield and grain N content. The treatment to change the N supply before winter is to apply N fertilizer to wheat before winter and planted wheat on stubble field and oat stubble field with N residues in different soil. Spring application of N in the total amount of 200kg / ha fertilization level, set early or late Shi, one-time application or graded application combinations. The 1985-1986 test also studied the effect of applying 50 kg N / ha in summer. In the two-year trial, seeding in September was more productive than in October. Compared with 1985-1986, the winter wheat sown in September 1986 to September 1987 had better growth during the winter, but the early advantage in plant growth and N absorption only increased the straw yield but did not increase the grain yield. In two years, the residues of oat stubble soil nitrogen were lower than the stubble. Soil nitrogen differences did not affect overwintering winter wheat growth and nitrogen uptake in October. From 1985 to 1986, the winter wheat growth and nitrogen uptake were limited due to poor weather conditions. Both N application before winter and N residual soil did not affect the wheat yield in September. In 1986-1987, the yield of oat wheat was 420 kg / ha less than that of the rapeseed crop, however, this reduction could be eliminated by applying nitrogen fertilizer to balance the soil N content. A one-off postponement of N application in April led to a reduction of wheat output, especially in the oat crop sown in September and no N fertilizer application before winter, while the remaining post-spring N