Optimizing water-fertilizer management to regulate soil environment can reduce greenhouse effect and enhance net eco-economic efficiency of wheat production

The dual challenges of ensuring food security and achieving carbon neutrality are placing increasing pressure on the sustainability of agricultural development. Agriculture is a significant source of global greenhouse gas (GHG) emissions, and irrigation and fertilization management are critical factors that influence GHG emissions from farmland. Thus, a field experiment was conducted for two years to evaluate the effects of drip irrigation and flood irrigation combined with different nitrogen application rates (N1: 120 kg ha−1, N2: 240 kg ha−1, and N3: 300 kg ha−1) on the wheat yield, GHG emissions, and net eco-economic benefits. Compared with flood irrigation, drip irrigation reduced the N2O and CO2 emission fluxes, and enhanced CH4 uptake, with only a marginal yield reduction. Economic analysis indicated that drip irrigation combined with N2 reduced the production inputs and carbon emission costs, improving the net eco-economic benefits. Under drip irrigation, moderate nitrogen application (240 kg ha−1) achieved the best balance among yield, emission reduction and economic benefits. These results highlight the potential of integrated water and nitrogen management for regulating soil conditions and microbial activity, thereby helping to reduce GHG emissions from farmland. These findings provide practical insights to facilitate the promotion of low-carbon agriculture practices, as well as a valuable reference for policy-making and decision-making under the goal of sustainable agricultural intensification. Future research should focus on long-term multi-site research and also consider soil carbon dynamics to refine farmland carbon footprint assessments and support carbon neutrality goals.