杜仲Eucommia ulmoides Oliv.属杜仲科,落叶乔木,对气候适应性强,较能耐寒,为温带及亚热带树种,我国特产,在长江中下游地区广为分布。其树皮、枝叶、果实中均含有大量重要的工业原料—杜仲胶。木材坚硬,洁白,纹理通直,可作家具等用材。皮、叶可供药用,有补肝益肾、强筋骨、降血压及安胎等功效。近年来内销出口量很大,尤其树皮,市场更为紧缺,价格由每公斤2元上浮到6—10元。国家医药总局已将杜仲列入重点保护和发展的木本药材之列。为促进杜仲生产的发展,于1986年秋对我场14年生的杜仲林进行了调查。现将调查结果及其经济效益初步分析如下: 一、林地概况 林地面积4亩。位于金湖县宝应湖农场园林场东河边,属里下河地区金湖县外滩地段。林地为砂壤土,pH7,含有机质2％、氮0.108％、磷11ppm、钾272ppm。地下水位汛期1.2米,平时2米左右。年降雨量800—1000毫米。无霜期205—210天。 1973年造林,株行距1.5×1.5米。当年成活率90％,第2年开始郁闭,4年生株高达4米,林相整齐。14年来未进行过施肥、除草 Eucommia ulmoides Oliv. Eucommia ulmoides Oliv. Branch Eucommiaceae, deciduous trees, adaptable to the climate, more able to cold, as temperate and subtropical species, our specialty, widely distributed in the middle and lower reaches of the Yangtze River. The bark, leaves, fruits contain a large number of important industrial raw materials - Eucommia gum. Timber hard, white, texture straight, for furniture and other timber. Skin, leaves for medicinal, Bugan Yishen, strong bones, blood pressure and tocolysis and other effects. In recent years, a large amount of domestic exports, especially the bark, the market is more scarce, prices rose from 2 yuan per kilogram to 6-10 yuan. State Administration of Secrets of Eucommia has been included in the focus of protection and development of woody herbs. In order to promote the development of the production of Eucommia ulmoides, a survey was conducted in the autumn of 1986 on Du Zhonglin, a 14-year-old man in our field. Now the survey results and preliminary analysis of their economic benefits are as follows: First, the overview of woodland 4 acres of forest land. It is located in the east bank of Baoying Lake farm garden in Jinhu County and belongs to the Bund section of Jinhu County in Lixiahe area. Woodland is sandy loam, pH7, containing 2% of organic matter, 0.108% of nitrogen, 11ppm of phosphorus and 272ppm of potassium. Groundwater flood season 1.2 meters, usually about 2 meters. Annual rainfall of 800-1000 mm. Frost-free period 205-210 days. Afforestation in 1973, spacing of 1.5 × 1.5 meters. The survival rate of 90%, the first two years began to close, 4-year-old plant up to 4 meters, neat forest. 14 years have not been fertilized, weeding