我县山地桔园多为红黄壤土,土种主要是紫粉泥土、黄泥土、红紫砂土、白岩砂土。据土壤普查测定,有机质含量较低,为0.78～1.19％,全氮量为0.048～0.053％,速效磷为2～13ppm,速效钾为86～100ppm,还缺钙(红紫砂土除外)、镁、锌、硼等微量元素。 近年来椿树表现出多种元素缺乏的症状:叶肉斑块状失绿黄化,叶脉绿色,呈肋骨状;叶脉木栓化,革质,叶片卷曲呈匙形;叶片狭长而小,似杨梅叶状;枝梢直立丛生;严重的整个叶片黄化而脱落;枝梢枯死,树势衰弱,产量低,品质差。虽经喷施磷酸二氢钾、硼砂,但肋骨状失绿黄化,叶 Orange County, my county is mostly red and yellow loamy soil, soil is mainly purple soil, yellow soil, red sand soil, white sand soil. According to the soil census, the content of organic matter is low, ranging from 0.78 to 1.19%, the total nitrogen is from 0.048 to 0.053%, the available phosphorus is from 2 to 13 ppm, the available potassium is from 86 to 100 ppm, and the calcium deficiency , Zinc, boron and other trace elements. In recent years, tortoise tree showed a variety of elements of the symptoms of lack of: leaf plaque lost green yellow, veins green, ribbed; leaf vein corked, leathery, leaf curled spatulate; leaves narrow and small, like bayberry Leafy; shoots erect tufted; severe yellow leaves and off; shoots dead, tree weakness, low yield, poor quality. Although sprayed with potassium dihydrogen phosphate, borax, but the rib-shaped chlorosis, leaves