Optimizing water and fertilizer management reduces carbon and water footprints for winter wheat production in China

The grand challenge for sustainable farming systems is to maintain agricultural productivity in a changing climate with water resource constraints. Here, we present a spatiotemporal footprint framework to optimize agricultural activities in winter wheat systems, based on a 30-year integrated assessment from 1991 to 2020 in China. During this period, agricultural activities in China's winter wheat production system emitted 66.6 × 10 6 t CO 2 eq yr -1 and consumed 112 × 10 9 m 3 yr -1 of water annually. The Huang-Huai-Hai Plain had high greenhouse gas emissions and water consumption, yet maintained relatively low product-level footprints. From 2001 to 2020, synergistic reductions in carbon and water footprints were achieved by optimizing fertilizer practices for yield improvement. Scenario-based mitigation analysis revealed that substituting organic alternatives for chemical fertilizers reduced emissions by 12%, while powering irrigation equipment with renewable energy lowered emissions by 7.0%, and improving irrigation efficiency reduced water consumption by 3%, relative to the baseline scenario. Together, precision fertilization and energy-efficient irrigation were highly impactful, reducing carbon emissions by up to 20% and being a practical strategy to enhance food security and environmental sustainability. • China's winter wheat emitted 66.6 Mt CO 2 eq yr -1 , consumed 112 km 3 water yr -1 . • Huang-Huai-Hai Plain had high wheat emissions and water use, low product footprints. • Fertilizer optimization and yield increases drove 2001-2020 synergistic reductions. • Scenarios: N cut/substitution, irrigation efficiency, renewable reduced footprints.