小麦夏玉米两熟连作制是丰县1980年以后采用的主要耕作栽培制度,目前已发展到60万亩左右,其产量约占全县粮食总产量的70％左右。但是,由于两熟连作茬口紧张,互相影响,如小麦播种迟,影响苗期早发,越冬前大分蘖不足,返青后无效分蘖多,成穗不足,穗型不大;后季玉米早发差,抽雄吐丝后气温下降,易造成秃顶,灌浆后期气温偏低,千粒重下降,成熟晚,又影响下茬小麦播种,因此,在同一块田里小麦夏玉米都要高产,难度很大。为此,我们于1986年9月28日小麦播种起到1988年9月21日玉米收 The system of double cropping of wheat and summer maize is the main cultivation and cultivation system adopted by Fengxian since 1980, and has now grown to about 600,000 mu. Its output accounts for about 70% of the total grain output of the county. However, due to the strain of double crop continuous cropping tension and influence each other, such as late sowing of wheat, affecting early seedling stage, lack of large tillering before winter, invalid tillering after turning back green, insufficient spike, panicle type; After the sprouting, the temperature of the spruce falls, causing the baldness easily. The temperature in the late grouting stage is low, the grain weight is declining, and the maturity is late, which affects the sowing of wheat in the next crop. Therefore, it is very difficult for the summer corn in the same field to produce high yield. To this end, we sown the wheat on September 28, 1986, to the corn harvest on September 21, 1988