1. Technical Centre for Soil, Agriculture and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing 100012, PR China
2. China Agricultural University, Beijing 100193, PR China
3. Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China
4. Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, PR China
5. Norwegian University of Life Sciences, Department of Environmental Sciences, 5003, N-1432 Ås, Norway