China and the U.S. account for 40% of the global nitrogen (N) inputs to crop and livestock production systems and have crop nitrogen use efficiencies (NUE) of only 26% and 50% respectively. Despite many technological developments, these rates have not significantly improved in recent decades. Meanwhile only about one-third of manure is recycled in both countries. These losses of nutrients from fertilizers and manures to the environment have led to serious water pollution, waste of resources and energy, and possibly unrealized crop yield potential. These inefficiencies highlight the need to identify the socioeconomic and technological barriers for improving the efficiency of N use in crop and livestock production, as well as the sustainability of the food-energy-water (FEW) nexus. The main goal of this project is to investigate and identify viable approaches to improve the sustainability of the FEW nexus through N management in crop and livestock production in China and U.S.
Recognizing differences between U.S. and Chinese agricultural systems and their socioeconomic contexts, a systems approach will facilitate a better understanding of the varying socioeconomic and technological barriers for NUE improvement, especially the factors beyond farm operations, and will help to unpack the N management challenges of each country. Specifically, this project will: 1) Characterize NUE and FEW sustainability in China and the U.S. on a county scale for crop and livestock production systems and their subsystems; 2) Investigate diverse socioeconomic and ecological drivers for NUE, manure recycling, and FEW sustainability, comparing key drivers in the two countries to inform NUE improvement; 3) Develop a policy-analysis tool to optimize the crop and livestock production systems for different FEW sustainability goals on spatial scale within each country; and 4) Assess the challenges and opportunities for 1-3 under different trade relationship scenarios. This project will advance knowledge of the dynamics in the FEW nexus by assessing the complex interactions between N management and the FEW nexus throughout the processes of crop and livestock production. The project will employ state-of-art models and recently available datasets and information, using consistent methodologies in both countries. Taking a comprehensive view of N flows across spatial, temporal, and system scales, this project will inform understanding of potential innovative policies, technology developments, impediments to adoption of improved management, and potential changes in production structure and trade for improving FEW sustainability.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
