内蒙古后山半干旱地区,扩大种草面积,实行粮草轮作,农牧结合,是培肥地力,改善生态环境,保护自然资源的重要途径.这个地区由于降水量少(年降水量300毫米左右),又无灌溉条件,水是限制农牧业生产发展的重要因索.根据农耕地土壤水分定位观测资料,一年一作在正常年份,土壤水分基本上能保持平衡,即蒸腾蒸发消耗的水分可以通过降水补给. In the semi-arid area of ​​the mountainous hilly area of ​​Inner Mongolia, expanding the area of ​​planting grass, implementing crop rotation and combining agriculture and animal husbandry is an important way to cultivate soil fertility, improve the ecological environment and protect natural resources. Due to less rainfall (about 300 mm in annual precipitation) , And no irrigation conditions, water is an important factor that limits the development of agriculture and animal husbandry.According to the observation data of the soil moisture in agricultural land, annual work in the normal year, the soil moisture can basically be balanced, that is, the water consumed by transpiration can Recharge by precipitation