在水稻抽穗期,传统的叶片增氮措施是土壤施氮,但由于水稻后期根系逐渐衰老、活力下降,加上土壤吸附和流水掠走,这种方法效果差、收益低。为了推广叶面喷施尿素技术、找出喷施的最佳浓度,我县于1984—85年进行了喷肥浓度试验: 供试品种中粳r34、泗阳731、盐粳2号等浓度分别设:1%、2%、3%、4%、5%和对照(喷清水)6个处理,用量折合每亩50公斤肥液。结果表明:喷肥的分别比对照平均增产11.2%、13.0%、15.3%、18.8%、9.5%,其中3%与4%两个浓度的增产幅 At the heading stage of rice, the traditional method of increasing nitrogen in the leaves is nitrogen application in soil. However, due to the gradual aging of the roots and the decrease of vitality of the roots at the late rice stage, this method is ineffective and has low returns because of soil adsorption and water swept away. In order to promote the technology of spraying urea on foliar surface and to find out the optimum spraying concentration, the test of concentration of fertilizer in our county was carried out in 1984-85. The concentrations of japonica rice R34, Siyang 731 and Yanjing 2 Set: 1%, 2%, 3%, 4%, 5% and control (spray water) 6 treatment, the amount equivalent to 50 kg of fertilizer per acre. The results showed that the average yield of spraying fertilizer increased by 11.2%, 13.0%, 15.3%, 18.8% and 9.5% respectively compared with the control, of which the increase rate of 3% and 4%