Improving nitrogen and water use efficiency in a wheat-maize rotation system in the North China Plain using optimized farming practices

Excessive nitrogen (N) application and shortage of water are the major obstacles to sustainable agricultural development in the high-yielding regions of the North China Plain. New cropping systems need to be created that use integrated management practices to improve the utilization of nitrogen and water and to reduce the emissions of greenhouse gases. We conducted a 4-year (2011-2015) field experiment in Huantai county using three cropping treatments: local farmers' conventional practices (FP), recommended farming management (REC), and no N fertilization (CK). The study revealed that, the mean annual grain yield of FP and REC was both 16.5 Mg ha−1 which was higher than CK (7.9 Mg ha−1). In comparison with FP, the REC treatment showed N fertilizer and groundwater input reduced by 43% and 28% with increasing of 79.3% and 61.7% of N use efficiency (NUE) and irrigation water use efficiency (IWUE), respectively. The REC treatment demonstrated consistently lower N2O emissions (36% on average) compared with the FP treatment. The annual net global warming potentials of the REC and CK treatments were 37% and 73% lower, respectively, than that of the FP treatment. The water footprint of the REC treatment was 30% (the Water Footprint Assessment method) to 37% (the Life Cycle Assessment method) less than that of the FP treatment. These results indicate that REC is a promising and feasible treatment for ensuring environmentally friendly, and energy-efficient sustainable agriculture in the high-yielding regions of the North China Plain.