Integrated assessment of agricultural land use policies on nutrient pollution and sustainable development in Taihu Basin, China

Water pollution in Chinese lakes is a major problem. To reduce nutrient pollution and enhance sustainable development in Taihu Basin, China, an integrated assessment of the impacts of agricultural land use policies has been performed, using the technical coefficient generator TechnoGIN and the bio-economic farm model FSSIM. Results show that although promotion of site-specific nutrient management (SSNM), the first policy, can improve regional objectives such as nutrient pollution reduction and food security, its adoption is constrained by labour productivity and availability at farm level. SSNM is more knowledge and labour intensive than conventional management, whereas labour availability is decreasing due to off-farm employment possibilities. In policy scenarios for 2015, environmental impacts are projected to decrease compared to 2008, partly due to the adoption of SSNM. However, the main reason is the decreasing labour availability towards 2015 which causes a switch from double to single cropping already in the baseline scenario for 2015. This leads to lower food production. Abolishing fertilizer subsidies for farmers that do not adopt SSNM, in combination with training appears to be the best way to stimulate SSNM adoption for improving the different land use functions. A second policy, stimulating mechanical transplanting of rice, reduces labour use and can become profitable when subsidized, but on most farm types it will not reverse the trend towards single cropping and has little influence on nutrient pollution. Thirdly, the regional policy of creating riparian buffer zones along water bodies appears to be promising, as it can strongly reduce nutrient leaching from farm land to rivers and lakes. Concluding, the integrated assessment performed in this study showed that policies can reduce nutrient pollution and improve sustainable development, but the changing labour context has a large impact on their impacts and on agriculture in the region.

► Integrated assessment of agricultural land use policies that reduce nutrient pollution. ► Policies that improve environmental, economic and social land use functions. ► Labour availability influences adoption of site-specific nutrient management. ► Labour limitation causes switch to single cropping and reduction in food production.