一、基本情况试验在湖北省北部襄樊市东津种畜场进行。该场位于襄樊市东南20公里的霸王山下,地处亚热带与温带交界处。是农、牧、渔业部的牧草种子生产基地,有二年生长的红三叶地200多亩,二年生长的白三叶地20多亩。年平均气温15—16℃,最高极温40℃,最低极温-10℃,年雨量900—1200mm,常出现冬、夏干旱现象, First, the basic situation Test in northern Hubei Province Xiangfan Dongjin breeding stock. The field is located 20 km southeast of Xiangfan City, King Hill, is located in the subtropical and temperate junction. It is the forage seed production base of the Ministry of Agriculture, Animal Husbandry and Fishery. It has 200 mu of red clover and 20 mu of white clover growing in two years. The annual average temperature of 15-16 ℃, the maximum temperature of 40 ℃, the minimum extreme temperature -10 ℃, annual rainfall 900-1200mm, often appear in winter and summer drought phenomenon,