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一、三要素过量不足及适量的营养生理 1、氮素:氮是柑桔栽培中最易缺乏的营养元素,施氮及缺氮时表现的效果与症状均很明显。氮素营养适量时,树的枝干伸长,叶片增大,叶色浓绿,有光泽,树木长势旺盛,果实产量亦高。而缺氮时,随缺乏程度显现出叶片中肋及叶脉的黄化,且叶形小,叶片薄,枝干伸长严重受到影响,从而树势衰退,产量减少,往往招致隔年结果。另外,当氮素营养过量而其它成分不足时,会导致枝干徒长,叶片暗绿柔软,开花结实数减少,也容易出现隔年结果的现象。如氮肥施用过多,则常导致树木长势过旺,从而在一段时期内产量剧增,但随后不久树势急剧衰退,严重时,还会出现异常落叶现象。柑桔叶片含氮比例通常较高,使用N~(15)的示踪结果表明:春叶发芽展叶所消耗的氮中,早春施下的氮最多占20％左右,其余部分来自树体贮藏氮素的再利用,普通温州蜜柑各器官氮素分布比例见表1。
First, the three elements of inadequate and inadequate nutrition physiology 1, Nitrogen: Nitrogen is the most easily lacking nutrients in citrus cultivation, nitrogen and nitrogen deficiency when the performance of the performance and symptoms are obvious. When the amount of nitrogen nutrition is adequate, the branches of the tree are elongated, the leaves are enlarged, the leaves are dark green and shiny, the trees grow vigorously and the fruit yield is also high. However, when nitrogen is deficient, yellowing of the ribs and veins of the leaves appears with the degree of deficiency, and the leaf shape is small, the leaves are thin and the elongation of the branches is severely affected. As a result, the decline of the tree vigor and the decrease of yield often result in the next year’s results. In addition, when nitrogen is overabundant and other components are not enough, it will lead to the growth of branches and leaves, the dark greenish green leaves and the reduced flowering and fruiting numbers, which also easily lead to the phenomenon of next year’s result. Excessive use of nitrogenous fertilizers, for example, often leads to overgrown trees, causing them to surge in output over a period of time, but shortly afterward the sharp decay of the trees and, in severe cases, abnormal deciduous foliage. The nitrogen content of citrus leaves is usually high, and tracing results using N ~ (15) show that the nitrogen consumed by spring leaf sprouting leaves accounts for about 20% of the nitrogen in early spring and the rest comes from the storage of trees Nitrogen reuse, the general distribution of nitrogen in the various parts of Satsuma mandarin percentage in Table 1.