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1.
In order to reduce the soil erosion rate on the Chinese Loess Plateau, the Chinese government launched in 1999 the “Grain for Green” program (GfG). The objective of this program was to increase the forest cover on steep slopes in the landscape by planting trees and sowing grasses on former cropland. The program was a massive investment by the Chinese government. By the end of 2005 the GfG-program was implemented in an area of 87,000 km2 in which about 400–600 million trees were planted. At present it is not known to what extent this program was successful. This paper examines the effects of the GfG-program on the mean annual vegetation cover in the Shaanxi province. A decadal time series of SPOT VEGETATION imagery from 1998 till 2005 were used to calculate NDVI-values in four counties with different rainfall regimes. By means of a regression between preceding rainfall and NDVI-values the effects of rainfall variability were filtered out. A trend analysis of the corrected NDVI time series pointed out that the GfG-program resulted in a significant increase of the vegetation cover on farmland in the northern part of Shaanxi province. In the southern part of the province, which has a more humid climate and large areas of irrigation farmland no significant increase of the vegetation cover on farmland could be detected.  相似文献   

2.
The role of agriculture in economic development and the development politics of promoting smallholder versus large‐scale agriculture have both been at the center of a long‐lasting and controversial debate. Using an innovative methodology which combines a value chain approach with input‐output‐analysis, the growth multipliers and productivity of both farm types in Guatemala are analyzed. Results show that smallholder agriculture has the same potential to stimulate output growth as large‐scale agriculture. Smallholder value chains include mainly informal sectors and create more jobs than commercial agriculture. Therefore, a reorientation of agricultural and land policies toward small‐scale food producers and within a comprehensive policy of integrated rural development is not only necessary in terms of social equity but also for boosting economic development.  相似文献   

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