【摘要】 用１５Ｎ示踪法研究了黄瓜中、下位叶片不同营养组合配施后１５Ｎ［（１５ＮＨ４）２ＳＯ４］进入黄瓜体内的速率、运移途径及利用效率。结果表明：黄瓜叶片能有效地吸收营养元素并将其迅速转移，不同叶位施肥，植株吸收的１５Ｎ在体内的运移主要发生在处理后７２ｈ之内，并且绝大部分转移至新生长点，老叶中１５Ｎ回收很少。叶面施用硫酸铵肥料的氮素在黄瓜地上部的分配率一般在５０．７％～６１．８％，随吸收时间延长，黄瓜营养体体积增大幅度（中位叶处理）有所提高。与单施氮肥相比，不同叶面营养组合配施均有明显提高氮素回收率和改善黄瓜地上部氮素营养的作用，尤以中位叶（第５叶）配施Ｎ＋ＰＫ＋微量元素（Ｃｕ＋Ｚｎ＋Ｆｅ＋Ｍｎ）＋天然植物生长活性物质的混合型组分效果最佳，表明植物的叶面营养仍应注意平衡供应和适宜的施用时期与施肥部位。更多还原

【Abstract】 The rate and pathway of translocation of sprayed 15 N labeled ammonium sulphate into cucumber tissues and the utilizing efficiency of N were studied in pot experiments by different foliar nutrient treatments at the middle and low leaves in position respectively. The sprayed nutrients could be absorbed efficiently by the cucumber leaves and translocated immediately after spraying. The translocation of 15 N taken up by cucumber leaves predominantly occurred within 72 hours after dipping of the leaves in different position and 15 N was found largely in the growing tissues. The 15 N recovery rate of foliar ammonium sulfate fertilizer in above ground part of cucumber was in the range of 50.7% to 61.8% and could increase with prolonging of absorbing time and expansion of leaf area i.e. dipping middle leaves. Compared to foliar nitrogen application alone, the combination treatments had significant effect on the foliar N uptake and improved the N nutrition status of above ground organs of cucumber. The function was greatest when foliar application of mixed N+PK+ mixed microelements (Zn+Mn+Cu+Fe)+NPGS at middle leaf in position (the fifth leaf) of cucumber. Therefore, the balanced supplement of nutrients, suitable plant growth periods and positions of leaves sprayed should be emphasized on foliar nutrition of plants.更多还原