广东省沙糖桔主产区果园土壤与树体养分状况分析

Analysis of Nutrient Status of Soil and Plants in ‘Shatangju’ Orchards in Main Production Areas of Guangdong Province

为了探讨沙糖桔叶片黄化与矿质养分的关系,对广东省沙糖桔主产区(肇庆市和云浮市)的53个果园进行土壤和叶片养分调查和分析。结果表明,沙糖桔果园土壤整体偏酸,有机质、土壤碱解氮、速效钾和有效锌含量基本上处于适宜水平,交换性镁和有效钙含量偏低,有效磷含量偏高;植株普遍缺氮、磷、镁和锌,缺乏程度以镁最严重;叶片中各养分间以及叶片养分与土壤pH值、有机质及其有效养分间存在着一定的相关性。缺镁是造成沙糖桔叶片黄化的主要原因。

To investigate the relationship between leaf yellowing and nutrient（especially Mg） status of ＇Shatangju＇（Citrus reticulata Blanco cv.Shatangju）,nutrients in soil and leaves from 53 orchards in the main production areas（Zhongqing and Yunfu） of ＇Shatangju＇ in Guangdong province were analyzed.Results indicated that all the ＇Shatangju＇ orchards soil was acidic.The contents of soil organic matter（SOM）,available N,K and Zn were at suitable level,exchangeable Mg and available Ca at lower level and available P at higher level.Leaf nutrient analysis showed that plants were lack of N,P and Mg,and DRIS analysis further indicated the deficiency of Zn and severe deficiency of Mg.Correlation analysis demonstrated certain relationships among various nutrients in leaves,and among nutrients in leaves and soil pH,SOM,available nutrients of soil.Mg deficiency was the most important reason for leaf yellowing of ＇Shatangju＇ in Guangdong.