黄土高原中低产土类型分布与治理开发途径

黄土高原有耕地2.8亿亩,属中、低产的面积占73.7％。中、低产土主要类型为风沙土、侵蚀土、旱薄土、盐渍土,广泛分布于风沙区、黄土丘陵区、黄土塬区、河谷阶地区和宁蒙平原区。由于风沙、水土流失、干旱、瘠薄、耕作粗放等原因,单位而积产量很低,有的亩产只有几十公斤,仅为当地气候生产潜力的15％～40％。改造中低产土的重点是侵蚀土和旱薄土,主要措施为兴修基本农田和增施肥料,提高单位面积产量,促进农林牧副业协调发展。“七五”期间,国家在不同类型区设立了11个小流域综合治理试验示范区,以改造中低产土为重点,开展综合治理,取得了明显成效。

Distribution of Soil Types with Medium and Low 0utput in Loess Piateau and Approaches of Its Management

The area under cultivation in the Loess PIateau is 280 million mu in which the area with medium and low output occupiese 73.7‰.The main soil types in these ateas include sandy soil,erosive soll,arid soil and saline soll.These types ofsoil distribute extensively in wind—borne sandy area,gullied rolling loess a rea,loess plateau.terrace area along river valley,and the plain a rea in Inner Mon—golia Autonomous Region respectively.Due to the erosion by wind and stormwater,d rought,barren and extensive cultivation,the yield per unit a rea is ve rylow,amounting only to seve ral ten kilogram per mu,which is only 15—40% of the potential productivity under the loca1 climate.Emphasis of reform in these medium and low yield areas should be put on the tansformation of a rid soi 1 anderosive soil.and the main measures a re as follow s:constructing basic fa rmlandand inc reasing the application of ferilizer to enhance yield per unit area:and promoting the coordinative development of agriculture,forestry animal hus—bandry and side—Iine.In orde r to transform soil with medium and low Yield.11 experimentaI plots for comprehensive、watershed management we re set uP in areas with different soil types during the impiementation of the seventh five—yea rplan and obvious benefits had been made through comprehensive conlrol