Mitigating life-cycle multiple environmental burdens while increasing ecosystem economic benefit and crop...

Nitrogen fertiliser is critical for increasing crop yields worldwide, but excessive use causes significant N losses in various forms and subsequent environmental issues, such as greenhouse gas (GHG) emissions. Establishing regional universal nitrogen strategy (RUNs) is indispensable for technology adoption, resource conservation, and pollution mitigation in crop production.

This study aims to develop a regional universal nitrogen fertilizer strategy to address variations in N application effectiveness, balancing agricultural productivity with environmental and eco-economic benefits.

We conducted a total of 48 site-year field experiments including no nitrogen application (Control), farmers' practice (FP), and the implementation of the RUNs with optimized nitrogen recommended formulas and one-off application method.

The RUNs significantly increased yields by 5.9%, 12%, and 11% for grain, sweet, and silage maize, respectively, compared with FP. Further, RUNs reduced life-cycle potentials of global warming, soil acidification, water eutrophication, and energy depletion by 22-45%, 63-76%, 51-73%, and 46-67%, respectively. The RUNs increased economic benefits by 11%-58.2%, and net ecosystem-economic benefits by 11.3-77.5%, particularly through the reduction of nitrogen fertiliser and labour-associated agricultural and ecological costs.

We propose that the RUNs reconciled crop yield, resource efficiency, environmental impacts, and ecosystem economic benefits, demonstrating a regional sustainable N strategy for global food security and resource conservation.