水土保持是对水土流失而言的。任何平地、梯田、草山、森林等陆地地表,绝对不产生水土流失的是没有的。只有当其侵蚀量超过土壤自然形成的速度,或因侵蚀使土壤肥力减退而影响植物的生产时,才称为土壤侵蚀,或称加速侵蚀。已经发生了这样侵蚀的地方,才需治理。反之,为生态环境所允 Soil and water conservation is concerned with soil and water loss. Any land, terraces, grass hills, forests and other land surface, there is absolutely no soil erosion is not. Soil erosion, or accelerated erosion, is called erosion only if it exceeds the rate at which the soil naturally forms or when the soil fertility is diminished by erosion. It has to be governed by the erosion that has taken place. On the contrary, for the ecological environment allowed