Xin Zhang: Decarbonization in a eutrophic world: Is nutrient-efficient agriculture a magic cure?

To decarbonize energy and food sectors, increasing attention has been paid to opportunities related to nutrient use in agriculture and beyond. Some opportunities focus on lowering the excess use of synthetic nitrogen (N) fertilizer, typically an energy-intensive product, or reducing emissions of nitrous oxide, a potent greenhouse gas. Meanwhile, other opportunities rely on the increasing use of nutrients, such as N and phosphorus (P). Examples of such decarbonization opportunities include growing biofuel crops as a renewable energy source, and using ammonia as a carbon-free shipping fuel. Therefore, managing nutrients more efficiently presents great potential in decarbonizing the economy and mitigating climate change. More efficient nutrient management is also critical for addressing the dual challenges of food security and eutrophication.



However, current efficiencies of N and P use in crop production are only 43% and 66% globally, and improving such efficiencies faces varying challenges among countries and regions. In this talk, I will use a unique dataset of nutrient budgets developed in my lab, demonstrate historical trajectories of nutrient use efficiencies for countries around the world, and discuss major challenges and opportunities in improving these efficiencies. I would like to argue that, to achieve nutrient-efficient agriculture, it is not only important to improve technologies and management practices on farms, but also to extend the scope of nutrient management by 1) considering the importance of socioeconomic conditions in addition to that of ecological processes; 2) extending the focus of efficiency on a single plot to the broad agro-food system; as well as by 3) engaging stakeholders beyond farmers and considering connections across countries. Ultimately, a realistic view of technology’s capacity to increase nutrient use efficiency paired with a better understanding of the socioeconomic impacts of nutrient-related decarbonization strategies (e.g., impacts on the livelihood of smallholder farmers in the global south) will help to guide decarbonization strategies in the increasingly eutrophic world.

Xin Zhang is an associate professor at the University of Maryland Center for Environmental Science (UMCES), and an editor for Earth’s Future, a transdisciplinary journal at America Geophysical Union (AGU). The goal of Xin’s current research is to use data-driven and transdisciplinary approach to guide the pursuit of sustainability. She evaluates how socioeconomic and biogeochemical processes affect the global nutrient cycle and the sustainability of agricultural production and, in turn, provides policy input on mitigating nutrient pollution while meeting global food and biofuel demands. Collaborating closely with scientists from a wide range of disciplines and stakeholders worldwide, Xin has initiated transdisciplinary and transnational research networks (e.g., the Sustainable Agriculture Matrix Consortium with transdisciplinary teams from six countries and regions), and published papers on high-impact journals, including three papers as the first or corresponding authors at Nature. In recognition of her efforts in interdisciplinary research and science application, Xin has received several awards, including the prestigious CAREER Award (by National Science Foundation, 2021), the President's Award for Excellence in Application of Science (by UMCES, 2022), and the Global Environmental Change Early Career Award (by AGU, 2022).

Xin received a Ph.D. from Yale University and worked as a postdoctoral research scientist at Princeton before joining UMCES.