Effects of fertilizer management on wheat yield, carbon and nitrogen footprint under drip irrigation

In order to salve the problem of excessive nitrogen (N) fertilizer input and unreasonable irrigation in wheat production, put forward the green high-yield production technology of wheat in North China Plain, and provide support for sustainable agricultural development. In this study, winter wheat was selected as the research object, five treatments were carried out: drip irrigation without fertilization (D-0), drip irrigation without nitrogen fertilizer (D-N0), border irrigation and conventional fertilization (Q-FP), drip irrigation and optimized fertilization (D-NPK), organic and inorganic fertilizer combination with drip irrigation (D-NPKM), the effects of different treatments on wheat yield, carbon (C) footprint and N footprint of wheat production were studied. The result indicated that N fertilizer and irrigation modes were the key constraint factor of wheat yield. Compared with Q-FP treatment, optimal fertilization and irrigation method (D-NPK) at the same time significantly increased wheat yield and harvest index by 12.3% and 13.2% on average, respectively, while D-NPKM treatment significantly increased wheat yield and harvest index by 16.8% and 13.1%, respectively. In addition, compared to conventional irrigation and fertilization practices by farmers (Q-FP), optimizing fertilization rate (D-NPK) and applying organic and inorganic fertilizers together (D-NPKM) under drip irrigation conditions were effective measures to reduce C and nitrogen emissions as well as environmental footprints in wheat production systems in this experiment: N footprints decreased by 61.7% and 59.8%, respectively, while C footprints decreased by 44.5% and 25.3%, respectively. Under the drip irrigation model, the N and C footprints of the D-NPKM treatment were higher than those of the D-NPK treatment by 4.9% and 34.6%, respectively, while the net ecological economic benefit of D-NPKM was 24.3% lower than that of D-NPK. Thus, considering from the perspective of wheat productivity, drip irrigation combined with organic and inorganic fertilizer application is the optimal measure. However, considering the ecological environment together, D-NPK treatment is recommended as the optimal approach. In summary, under the conditions of this study, it is recommended to adopt drip irrigation combined with optimized fertilization as the optimal strategy for wheat production. Nevertheless, compared to conventional irrigation and fertilization by farmers, organic and inorganic fertilizer application under drip irrigation remains an effective measure to enhance wheat productivity and reduce C and N footprints in wheat production. Future research could focus on integrating organic fertilizer resources from different regions to identify types and application methods that can further reduce C footprints, thereby maximizing resource utilization and achieving sustainable agricultural development.