一、前言我国是一个多山国家,平地只占国土面积的34％,不少农地是倾斜度不一的坡耕地。譬如,在黄土高原丘陵沟壑区的15.5万平方公里土地面积中,0～5°的坡地面占10％,6～25°的坡地占58％,大于25°的坡地占32％;又如陕西省的商洛地区,全区有耕地面积259.35万亩,坡耕地占76.78％; I. Foreword China is a mountainous country, with flat land covering only 34% of the land area. Many farmlands are sloping fields with different slopes. For example, of the 155,000 square kilometers of land in the hilly and gully regions of the Loess Plateau, 0 to 5 ° of slope land occupies 10%, 6 to 25 ° of slope land occupies 58% and more than 25 ° of slope land occupies 32% The province of Shangluo, the region has 259.35 acres of arable land, sloping farmland accounted for 76.78%;