为了更好地利用农区的草山草坡,增加草层植物种类,我们从1982年开始进行草山草坡改良试验。一、试验点的选择及自然条件试验点选择在陵川县城北7公里外的黄沙山。其地理位置约在北纬35°47′,东经113°16′,海拔1,330—1,487米,年平均气温7.9℃,日平均气温1月份最低-7—-10.7℃,7月份最高25.7℃。极端最高气温34.3℃,最低气温-27.3℃。年平均降雨 In order to make better use of grassy hills and grasslands in rural areas and increase the types of grassy plants, we started to carry out grassy slope improvement experiments in 1982. First, the choice of test points and natural conditions Test Point Select Lingchuan County, 7 km north of the Yellow Sand Hill. Its geographical location is about 35 ° 47’N, 113 ° 16’E, 1,330-1,487 meters above sea level, and its annual average temperature is 7.9 ° C. Its daily mean temperature is the lowest in January-7-10.7 ° C and the highest in July is 25.7 ° C. Extreme maximum temperature 34.3 ℃, the lowest temperature -27.3 ℃. The average annual rainfall