Assessment of ecological, economic and social impacts of grain for green on the counties of north Shaanxi in the Loess Plateau, China: A case study of Mizhi County

In order to noticeably and systematically assess ecological, economic and social effects of the grain for green project on county level, this study investigated the benefits of carbon sequestration to the soil of farmland-converted forestland (in 0 to 20 cm soil depth), the change in household income structure and social harmony. The results showed that, the soil organic matter content and organic carbon density of the forest land were 0.315% and 0.39 kgC/m(2) higher than those of the slope farmland and this change of land use brings about biological and economic benefits of soil carbon sequestration (in 0 to 20 cm soil depth) with a value of 16, 070,000 Yuan. The study surveyed the income structure and opinions of 50 farm households towards the grain for green project in 2010. Compared with their incomes 10 years ago, 69% of the farm households increased their net incomes 2 to 5 times, 56% of the farm households only increased their net incomes 0 to 1 time and 70% of the farm households had migrant workers whose income accounted for more than 50% of the net incomes of 63.6% of their farm households. According to the modified fundamental orientation theory, a society with a coordination coefficient of fuzzy membership of 0.87 belongs to the category of basic coordination state. The findings further revealed that, the grain for green project improved the counties concerned in regional ecological environment, farm household income, economic restructuring and optimization and social harmony.