夏收后播种的大豆,由于农时紧,耕作粗放,基肥甚少,加之六、七月份常出现少雨旱象,水、肥不足,最容易引起大豆花荚脱落,使产量下降。对此应采取以下防范措施。一、合理留苗:夏大豆留苗数量,以盛花期后正好封行为宜。封行过早,说明留株太密,花荚脱落多;封行过迟或不封行,说明留株过稀,个体发育虽好,但难保产量。水、肥条件好的地块宜适当稀播;瘠薄田适当密留苗。二、合理排灌:大豆始花至盛花期,需水量最多。这时若干旱缺墒,会使植株生长受阻,开花减少,容易落花。到结英期遇旱也易落荚减产。所以,应及时灌水,降雨后要松土保墒。 Sowing summer harvest, due to tight farming, intensive farming, very few basal fertilizer, combined with six or seven months often appear dry weather, water, fertilizer, the most likely to cause loss of soybean flower pods, so that the decline in production. This should take the following precautions. First, a reasonable Liao Miao: Liao Miao number of summer soybean in order to seal after the full bloom should be appropriate. The premature closure of the seal shows that the plant is too dense and the flower pods are shedding too much. The closure of the seal bank is too late or not sealed. This shows that the strain is sparse and the individual development is good, but it is hard to guarantee the yield. Water, fertilizer conditions should be appropriate land suitable plots sowing; barren field appropriate seal seedlings. Second, rational irrigation and drainage: the flowering of soybean flower flowering, water demand up. At this time arid drought, will make the growth of plants blocked, flowering reduced, easy to fall flowers. To the United Kingdom in the case of drought is also easy to fall pod yield. Therefore, irrigation should be promptly, soil moisture after loosening.