1. Institute of Agricultural Economics and Development, Chinese Academy of Agricultural Sciences, Beijing, China
2. Academy of Agricultural Planning and Engineering, Beijing, China
3. State Key Laboratory of Efficient Utilization of Arid and Semi-Arid Arable Land in Northern China, Institute of Agricultural Resources and Regional Planning, and the Key Laboratory of Agricultural Remote Sensing, Ministry of Agriculture and Rural Affairs/Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China