Study On Cultivation Of The Slopelands Purple Soils By Different Agricultural Measures

Purple slopeland soils are widely distributed in Three Gorge Reservior Area, where the loss of water and soil is serious. Through the field runoff observation , laboratory soil analysis and mensuration of crop yield from 6 hedgerows plots,5 different cultivation modes(terrace and slopeland cultivation) and different kinds of land use and combination field investigation in Wangjiaqiao Watershed at Zigui country, researching all kinds of benefits of purple soils in different measures, the results indicate:The simulated rainfall shows that though hedgerows retard and influence soil particles and runoff(the simulated rainfall, shows that soil eroded sediment and runoff of 1-2 plot are amount to 20.2492k 43.8% of 1-1 plot), accelerate nutrients dissolution; secondly fertilization and coverage also influence eluviation of nutrients.The topography of hedgerows plot changes and micro-topography drops or rises under erosion and erosion control measures. Synchronously the study of distributions of soil particles with different sizes shows that the >0.2mm particles relatively concentrate in erosion, and the loss of the <0.02mm particles are controlled by planted hedgerows. Further the study of distributions of soil particles in several measures shows that the 0.2-0.002mm particles more controlled in terrace than in slopeland in erorion.The diversity of soil particles by runoff taken in rainfall induces the distributions of the nutrients content have a regulariy among hedgerows rows: the nutrients content is lowest in middle row, and others is relatively higher.Through study of the changes of soil nutrients in different time in erosion, the results show that hedgerows with fertilization can effectively improve soil nutrients content and is a good measure in reforming in soil; in addition terrace can more control soil erosion and cultivation soil than slopeland, and the impart of planted orange in terrace is best.Hedgerows with fertilization and coverage can effectively cultivate soil, and yield of 1-6 plot is 345% of the 1-1 plot's. In addition study of the ratios of input and output of economy, the results show that the ratio is 6.24 of planted orange in terrace, and 4.63 of slopeland. So planting orange in terrace not only effectively controls soil erosion, but also improves the farmers income.