The North China Plain (NCP) is one of the most important grain production regions in China. However, it currently experiences water shortage, severe nonpoint source pollution, and low water and N use efficiencies (WUE and NUE). To explore sustainable agricultural development in this region, a field experiment with different cropping systems was conducted in suburban Beijing. These cropping systems included a winter wheat and summer maize rotation system for one year (WM), three harvests (winter wheat-summer maize-spring maize) in two years (HT), and continuous spring maize monoculture (CS). Novel ways were explored to improve WUE and NUE and to reduce N loss via the alternative cropping system based on the simulation results of a soil-crop system model. Results showed that the annual average yields were ranked as follows: WM > HT > CS. The N leaching of WM was much larger than that of HT and CS. WUE and NUE were ranked as follows: WM < HT < CS. Comprehensive evaluation indices based on agronomic and environmental effects indicated that CS or HT have significant potential for approaches characterized by water-saving, fertilizer-saving, high-WUE, and high-NUE properties. Once spring maize yield reached an ideal level HT and CS became a high-yield, water-saving, and fertilizer-saving cropping systems. Therefore, this method would be beneficial to sustainable agricultural development in the NCP.
Role of Ammonia on the Feedback Between AWC and Inorganic Aerosol Formation During Heavy Pollution in the North China Plain
