为了防止牲畜闯进菜园,或者说防止行人抄近路而践踏蔬菜,菜农总是在种菜之先种下篱笆,将自家的菜园“圈养”起来。但是,农民与经济学家同样认识到了篱笆的经济与不经济。一是篱笆成为事实之后,将沿篱笆墙的土壤恰当给予耕种,便有可能比土地中央所找到的土壤更加肥沃;二是碰到树桩的几率大了,也 In order to prevent livestock from breaking into the vegetable garden, or to prevent pedestrians from cutting short ways and trampling vegetables, the vegetable growers always planted their hedgerows before growing their own vegetable gardens. However, farmers and economists also recognize the economic and uneconomical nature of fencing. First, when the fence becomes a reality, the soil along the fence will be appropriately cultivated, which may make it more fertile than the soil found in the center of the land. Second, the probability of encountering stumps is high, and