Land Use Forms supporting Sustainable Agriculture in Sloping Farmlands

从坡耕地农业可持续发展的角度出发，分析了坡耕地的开沟措施、道路和水道的布置以及农民的水土保持措施对土壤侵蚀的影响。选择大面积种植日本萝卜的开垦高地为试验区，通过无线电遥控飞机在航空照片上读取土地利用形式和垄沟方向，调查实际开沟措施和土壤侵蚀模式，以明确泥沙来源，并向农民发出关于保护措施的调查问卷。主要研究结果如下：1.通过对不同耕作方式的地貌特征分析，发现犁沟倾向于沿田界沿着平缓方向形成，并在犁沟末端造成土壤侵蚀.不犁沟的裸地比犁沟的裸地产生更多的泥沙。有效的土壤保持措施需要一个合适的田间布局和一条沿着田间边界的草道来补偿许多农民的努力。农户对作物的可利用性和排水系统有一定的关注，没有受到重茬带来的土壤侵蚀的伤害。虽然轮作制度对土壤保持是必不可少的，但小农场主的盈利经营需要有荒地。有效的基础设施，改善作物的可操作性和排水系统和保护措施相结合，进行可持续农业。

From the viewpoint of sustainable agriculture in sloping farmlands, we analyzed soil erosion conditions affected by the furrowing practices, the arrangement of roads and waterways and farmars' conservation practices. Selecting the test area composed of reclaimed upland fields which had been cropped with a Japanese radish in wide area by monoculture, we read the land use forms and the direction of ridges and furrows on air photos by radio controlled airplane and surveyed the actual furrowing practices and soil erosion patterns to make the sediment source clear, and sent out a questionaire to farmers on their conservation practices. The results obtained were as follows.1. Analysing the geomorphic features of furrowing practices showed that furrows tended to be formed in a more gentle direction along the field boundary and caused soil erosion at the furrow ends.2. Bare fields without furrows had yielded much more sediment than with furrows.3. Effective soil conservation practices need a suitable field arrangement and a grass waterway along the field border to recompense for many farmers' efforts to conserve.4. Farmers had partly paid attension to cropping workability and draining systems without injury by continuous cropping to bring soil erosion.5. Though a rotational cropping system was essential to soil conservation, vergin lands were required for the profitable operate of a small farmer.6. Effective infrastructures which improve cropping workability and drainage systems and the conservation practices are combined to conduct the sustainable agriculture.