西北地区以石灰性土壤为主,土壤微量元素有效性较低,种植猕猴桃易出现黄化现象.采集正常和黄化猕猴桃叶片及其树冠下土壤样品进行营养诊断分析.结果表明,除Ca外,黄化叶片中N、P、K、Cu、Fe含量均较低,与正常叶片含量相比差异达极显著,其中Cu和Fe分别为正常叶片的66.85％与65.61％.铁是叶绿素合成的必需元素,表明黄化原因与缺铁有关.正常和黄化树体下土层各养分测定值差异不显著；说明植株叶片养分缺乏是植株根系吸收养分受阻,与土壤养分丰缺无关.需要通过改善土壤的其他条件(如pH,水分,通气状况等)或叶面喷肥来促进树体吸收.%The availabilities of trace elements in calcareous soil which is the main soil type in northwest of China are low. Iron-deficiency chlorosis is a common phenomenon to kiwi in calcareous soil. Leaves and soil samples of the normal and chlorosis kiwifruit trees were studied with nutrient diagnosis method. Except for calcium, the concentrations of nitrogen, phosphorus, potassium, copper and iron in leaves of chlorosis trees were significant lower than that of normal trees, especially copper and iron, contents of which in leaves of chlorosis trees were 66. 85% and 65. 61 % of normal trees, respectively. Iron was an essential element for chlorophyll synthesis, which showed chlorosis was related to iron deficiency. There were no significant differences with soil nutrients content between normal trees and chlorosis trees, which indicated the deficiencies of nutrients in leaves attribute to the obstruction of nutrients to absorb by root, and there was no significant relationship with the abundance and deficiency of soil nutrients. Absorption ability of trees could be improved through foliage fertilization, regulating soil pH value, moisture, aeration and so on.
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