The Agricultural Planting Structure Adjustment based on Water Footprint and Multi-objective Optimization Models in China

Abstract ：Aimed at solving the practical problems of the water resource shortage and the unreasonable agricultural planting structure in north China, this research looked at adjusting agricultural planting structure to save water. The agricultural structure of Zhangjiakou was optimised in terms of saving agricultural water, reducing pollution and increasing economic output. Taking "reduction of irrigated land + effective utilisation coefficient of irrigation water + planting structure adjustment” as the optimal path, the optimal agricultural planting structures were determined for water-saving scenarios of 15%, 20% and 30%. (1) Vegetables have the largest economic contribution, reaching 58.94%. Potato has the second-highest economic contribution and the largest water footprint, reaching 2461.41 ×106 m3. (2) Potato, vegetables and corn, with the larger TN pollutant accounting for 36.44%, 18.20% and 17.18%, were the main crops whose planting scales that needed to be reduced, while oil plant, fruit, naked oat and bean were the main crops whose planting scale could be increased. (3) From a comprehensive comparison of the amount of water saved and the benefits to the environment, the 15% water-saving plan was the best, and the cumulative reduction of pollution was 766.40 t. It is essential to adopt a combined approach of reducing irrigated land reduction, controlling crop scale and using water-saving irrigation methods to develop green and efficient water-saving practices and along with the implementation of precision agriculture techniques.