一雁北西山包括左云、右玉、平鲁三县。共有人口30多万,总土地面积839万亩,其中水土流失面积613万亩,属黄土高原水土流失重点区之一。这里地广人稀,宜牧面积广大,牧草品种较多,畜牧业基础较好,客观上存在着发展牧草生产的有利条件。早在60年代,这里就先后试验和推广了草木樨、野 A North West Mountain, including Zuo Yun, Youyu, Pinglu three counties. A total population of more than 30 million, the total land area of ​​839 mu, of which 613 mu of soil erosion area, is one of the key areas of soil erosion in the Loess Plateau. Sparsely populated here, Yi Mu vast area, more forage species, animal husbandry based on better, objectively there is the favorable conditions for the development of forage production. As early as the 1960s, it has successively experimented and popularized the vegetation and wild plants