Research Briefing in 2024

With centralized production, the price of ammonia-based fertilizers is affected by the volatility of the fossil fuel market, complex supply chains and long-distance transportation costs. Now, an analysis of the cost-competitiveness of decentralized low-carbon ammonia production suggests that a substantial fraction of the global ammonia demand could be cost-competitively supplied by small-scale technologies by 2030.

We provide evidence that intensive industrialization over the past century, particularly of the livestock trade, has facilitated host jumps and accumulation of antimicrobial resistance genes in Salmonella enterica, leading to the global transmission of this pathogen from Europe and the USA during the height of pork production.

We found trade-offs among the environmental and animal welfare impacts of pig farms — those that had low greenhouse gas emissions typically had low land use but poor animal welfare and high antimicrobial use. Some farms performed well in all four impacts, but these farms were not consistently associated with any particular farm or label type.

Returning agricultural organic residues to the soil is imperative for food security and carbon neutrality. We scaled up field findings using machine learning and found that the co-benefits of improved rice yield and reduced net carbon emissions can be realized with integrated management of organic residues and water worldwide.

We present an interdisciplinary conceptual framework of urban agriculture and synthesize its social–ecological effects across scales. Using those theoretical foundations, we proposed a multiphase developmental pathway for scaling up urban agriculture, including dynamics, processes, accelerators and feedback loops, which elucidated key considerations associated with achieving transformative change in urban regions.