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本文讨论了长江上游水源区云南境内土壤侵蚀的范围、程度和保持状况。长江发源于中国西部的青藏高原,横贯大陆西东,全长6380km,其源头位于地壳活动和地质不稳定的高原区,流域区是以水稻生产为主的、土地利用程度较高的农业主产区,所以,土壤侵蚀极其严重;随着三峡大坝的修建,土壤侵蚀产生泥沙淤积将降低水库的使用效率等问题,致使土壤保持成为该区必不可少的措施之一,土壤侵蚀问题正越来越受到关注。文章回顾了云南省的土壤保持工作,并以东川、寻甸为例,阐明了云南省的区域土壤保持措施。在云南农业大学农场正在进行的径流区实验被用于评估不同土壤保持措施的效果。试验选择种植当地的主要作物玉米(Zea mays),采取传统的栽培方法,在三个不同的坡度上,沿等高线种植和顺坡向下垂直种植等处理进行,试验地条件与生产上的坡耕地一致。1993～1996年的研究结果表明:一般情况下,沿等高线种植的地区,土壤侵蚀率较低,采取这种措施,平均侵蚀率为顺坡向种植的0.69;秸秆覆盖和沿等高线种植是比较有效的土壤保持措施。
This paper discusses the scope, extent and maintenance of soil erosion in the water source area of Yunnan in the upper reaches of the Yangtze River. The Yangtze River originates from the Qinghai-Tibet Plateau in the western part of China. It runs across the western part of the mainland with a total length of 6,380km. Its source lies in plateau areas where the crustal activity and geology are unstable. The drainage area is dominated by rice production with a high degree of land utilization Therefore, the soil erosion is extremely serious. With the construction of the Three Gorges Dam, sedimentation of soil erosion will reduce the reservoir utilization efficiency and other issues, resulting in the soil to become one of the essential measures in the area. Soil erosion is positive More and more attention. This paper reviews the soil conservation work in Yunnan Province, and takes Dongchuan and Xundian as examples to illustrate the regional soil conservation measures in Yunnan Province. Ongoing runoff experiments at the farm of Yunnan Agricultural University were used to assess the effectiveness of different soil conservation measures. The experiment chose to cultivate Zea mays which is the main crop in our country and took the traditional cultivation method. The cultivation was carried out on three different slopes along the contour planting and downslope vertical planting. The experimental conditions and production slope Arable land. The results from 1993 to 1996 showed that under normal circumstances, the soil erosion rate was lower in the areas planted along the contour lines. With this measure, the average erosion rate was 0.69 along the slope, and the straw mulching and along the contour lines Planting is a more effective soil conservation measure.