清代中晚期山地种植玉米引发的水土流失及其遏止措施

清代中晚期，我国渭河至黄河下游一线以南、青藏高原以东范围内，人们广泛开垦山地，种植玉米，许多地方出现了“遍山漫谷皆包谷”的景象。大面积的山地开垦和玉米种植，破坏了原有的自然植被，引发严重的水土流失。在不同地区，官方和民间对开山种玉米的利弊有不同认识。在四川、湖北、湖南等省，政府对开辟荒山种植玉米的行为基本上是听之任之；但在浙江、皖南和陕南等地，政府和民间曾采取多种积极措施，遏止山地种植玉米引发的水土流失，并取得了一定成效。

Soil Erosion because of Extensive Corn Planting on Mountain Country and Restraining Measures in China from Middle to Late in Qing Dynasty

From about 1700 to the late of 19th century, south of Wei River and Yellow River, east of Qingzang plateau, large area with comparatively high altitude and was not good for the traditional grains of china ,had been opened up extensively for planting com. In many places, the valley and hillside had been covered only with com. Meanwhile, the original vegetation had been destroyed seriously, and caused grave soil erosion. Different understanding existed in different places and some measures were taken. In Sichuan, Hunan and Hubei provincesetc, planting corn on mountains was permissive; While in Zhejiang,south Anhui and south Shanxi, the local government and people took series measures to prohibit planting com on mountains, and acquired certain effect.