一、引种区概况引种区在安塞县茶坊我所基点。该点在延安西北部杏子河流域,位于东经109°15′,北纬36°45′,属黄土丘陵沟壑区。山地植被稀少,气候干旱,各年降雨量不均,多年平均年降雨量572.3毫米,集中在7、8、9三个月。多暴雨,春季干旱,年平均气温9.3℃,最高39.7℃,最低-25.4℃。全年平均日照2464.9时。土壤为黄绵土。造林地海拔高约在1,000—1,200米。坡向有阳坡、半阳坡、半阴坡。造林地为农地或荒地。核桃树在本区有零星栽植,结实晚,抗性差,果实个小,产量低。因此,于1973年秋开始在沿河湾公社茶坊大队引种良种核桃,以后又扩展到方塌、峙崾(山先)等大队。现共有良种核桃林约465亩,6,700株。二、主要类型1966年春由新疆的阿克苏、库车等县弓 First, the introduction of the introduction of the introduction area in Ansai County Chafang I point. The point is in the Xingzi River basin in the northwestern part of Yan’an. It lies at 109 ° 15’E and 36 ° 45’N, and belongs to the loess hilly and gully area. Mountain vegetation scarce, arid climate, uneven annual rainfall, annual average annual rainfall 572.3 mm, concentrated in 7,8,9 three months. Rainstorm, spring drought, the annual average temperature of 9.3 ℃, the highest 39.7 ℃, the lowest -25.4 ℃. The average annual sunshine 2464.9 hours. Soil is loessial soil. Afforestation altitude of about 1,000-1,200 meters. Slope has a sunny slope, semi-sunny slope, semi-shady slope. Afforestation for the farmland or wasteland. Walnut trees in this area have sporadic planting, late, poor resistance, a small fruit, low yield. Therefore, in the autumn of 1973, the introduction of seeds and walnuts in the tea plantation of Yanhewan Commune started to spread to the brigade of Fangcao and Zhihe (Shanxian) in the autumn of 1973. There are total about 465 acres of walnut forest, 6,700 strains. Second, the main type Spring 1966 by the Xinjiang Aksu, Kuche County bow