夏大豆在高温多雨季节生长发育快,管理回旋余地小,稍有忽视田间每一项细小措施的累加作用,易发生豆苗旺长,甚至倒伏。特别是肥水条件比较充足的地块,施肥不当,氮素肥料过多,易出现嫩旺苗。播量过大,留苗过多,基本苗超过2万株以上,常常造成植株间遮光严重,降低光合效率,导致个体发育不良,群体质量差,极易在中后期发生倒伏,籽粒不能正常成熟。根据调查,常年夏大豆倒伏面积约占15%～20%,高密度、偏施氮肥的田块占80%以上,遇到这种现象,促其转化和防治措施如下: 1.精播育壮苗 Soybean growth and development in the high temperature and rainy season fast, little room for maneuver management, a slight neglect of the cumulative effect of each field of small measures prone to flourishing flourishing, or even lodging. In particular, more adequate fertilizer and water conditions of the plots, improper fertilization, nitrogen fertilizer too much, prone to tender Wang Miao. Sowing too much, too much seedlings, the basic seedlings more than 20000 or more, often resulting in serious shade between plants, reducing photosynthetic efficiency, leading to poor development of individuals, groups of poor quality, prone to lodging in the late, the grain can not be normal maturation . According to the survey, perennial summer soybean lodging area accounts for about 15% to 20%, high-density, partial nitrogen fertilizer field accounted for more than 80%, encountered this phenomenon, and promote its transformation and prevention measures are as follows: seedling