人们一致认识到土壤侵蚀问题,在干旱和半干旱地带要比温带和热带严重得多,这是由于气候、土壤、土地使用和其它诸方面的原因造成的.土壤侵蚀问题使干旱环境中地被植物少于正常数量的形势趋于恶化.绝大多数发展中国家国土的全部或局部位于干旱和半干旱地带.另一方面,人们还认识到,为牧业生产提供主要饲料资源的牧场占据着干旱地区的绝大部分土地.然而,这些牧场的使 It is unanimously recognized that the problem of soil erosion is much more severe in the arid and semi-arid zones than in the temperate and tropical regions due to climate, soil, land use and other causes. The situation with less than normal numbers of plants tends to worsen, with most or most of the land of developing countries residing in the arid and semi-arid zones, and on the other hand, it is also recognized that pastures that provide the main feedstock for animal husbandry occupy The vast majority of land in arid regions. However, the use of these pastures