叶面喷肥有吸收快、利用率高等优点,最大缺点是浓度高时易灼伤叶片.国内外除低容量喷肥用较高浓度外,常规喷肥通常用大水量低浓度的方法.查阅了国内提及棉花喷肥的文献计30多篇,人工喷尿素浓度没有超过2%的.Wittwer等1963年报道棉花叶面喷尿素可忍受的浓度相当于2～5%.Neumann1975年提出用尿素喷雾通常没有不利影响的浓度为2%.Hodgson等1988年报道,不同年份进行棉花喷尿素试验,用低容量喷雾时,浓度相当于35.7%,普通喷雾浓度仅为1.78%.Finck1981年报道尿素喷肥使用的最高浓度为15%,在有关表格中列入8%以上浓度的只是禾谷类等作物,敏感作物的推荐浓度为0.5～1%.低浓度大水量的方法花工多,低容量喷雾或飞机航喷,虽可提高喷肥浓度,但又受到器械限制,这者限制了喷肥的应用范围.通过数年研究,我们已摸索了一种高浓 Foliar fertilizer has the advantages of fast absorption, high utilization, the biggest drawback is the high concentration of easy to burn leaves at home and abroad in addition to low-volume spray with a higher concentration, the conventional method of spraying large amounts of water is usually low concentration. The domestic reference to cotton fertilizer accounting for more than 30 articles, artificial urea concentration did not exceed 2% .Wittwer et al reported in 1963 cotton foliar urea can withstand the same concentration of 2 ~ 5% .Neumann1975 introduced a Usually not adversely affected by the concentration of 2% .Hodgson et al reported in 1988, different years of cotton spray urea test, with low-volume spray, the concentration is equivalent to 35.7%, the ordinary spray concentration of only 1.78% .Finck1981 reported Kenzi The highest concentration used is 15%. Only 8% or more of the above table is included for crops such as cereals. The recommended concentration for sensitive crops is 0.5% to 1%. Low concentration Large amount of water Method Sprinkler or low volume spray or Aircraft jet, although it can increase the concentration of fertilizer, but by the instrument restrictions, which limits the scope of application of fertilizer through years of research, we have explored a high concentration