红壤甜橙园植株锰镁锌营养失调的诊断

Diagnosis of Manganese, Magnesium and Zinc Disturbance for Sweet Orange Plants on Red Soil

对福建南靖县朝阳山柑桔场柳橙和改良橙叶片黄化进行了研究。根据叶片黄化症状及土壤、叶分析结果,确认该黄化现象系植株缺乏锰、镁、锌元素所致。有黄化症状植株叶片锰、镁、锌含量分别为6.7×10^(-5)～20.5×10^(-6)、0.193％～0.194％、18.0×10^(-6)～21.5×10^(-6),均低于适宜范围值。认为植株锰和镁元素的缺乏是土壤中代换性锰、易还原锰和代换性镁含量低所致;而锌元素缺乏与土壤和植株中含磷量过高有关。

According to the leaf symptoms and the results of leaf and soil analyses, it has been determined that the leaf yellowing of Liucheng(sweet orange)and Gailiangcheng (sweet orange)plants at Chaoyangshan Fruit Farm in Nanjing county of Fujian province was caused by Mn,Mg ,and Zn deficiency. Mn,Mg and Zn levels in yellowing leaf were 6.7—20.5 ppm, 0. 193--0. 194% and 18.0--21.5ppm, respectively, which were lower than the suitabale value range. It was suggested that Mn and Mg deficiency was caused by the low contents of exchangeable Mn, easily reducible Mn and exchangeable Mg in soil,whereas Zn deficiency was related to phosphorus excess in plant and soil.