Clean Agriculture

The food system of urban agglomeration undergoes continuous transitions and poses changing pressure to the environment, especially in terms of nitrogen (N) pollution. This study highlights the decreased N use efficiency and intensified local N pollution in the context of uneven agricultural contraction in urban agglomeration and reveals how cities can leverage synergies for coordinated N pollution mitigation.

The exact contribution of food systems to air pollution is unknown. On the basis of the European Commission’s EDGAR-FOOD database, a global emission inventory of air pollutants from the food systems, this study quantifies historic emissions of major pollutant compounds at each stage of the food supply chain at country level.

Most research on the impacts of food loss and waste (FLW) looks at food security, resource use and climate. Based on product-level FLW data and an NH₃ emission inventory, atmospheric chemistry simulations reveal the potential of FLW reductions in mitigating PM_2.5 air pollution and nitrogen deposition.

A large share of all food produced for human consumption is internationally traded, including foods with important public health implications such as fruits, vegetables, legumes, nuts and red meat. Using bilateral trade data and food-specific risk–disease relationships, this study estimates the impact of food imports on diet-related health effects per country.

Estimating the global cropland N₂O mitigation potential is limited by the uncertainty and variability of direct emission factors (EFs). Here, using a data-driven approach with 1,507 chamber-based field observations of EFs, the study shows that EF variation is primarily driven by climatic and edaphic factors. Two-thirds of the mitigation potential could be achieved on one-fifth of the global harvested area, mainly located in humid subtropical climates and across gleysols and acrisols.

Between 1998 and 2016, tillage intensity across the US corn–soybean cropping systems shifted from a decreasing to an increasing trend. The decreasing tillage intensity is correlated to the wide adoption of herbicide-tolerant crops, whereas the tillage reintensification is found to be related to the emergence of herbicide-resistant weed species after 2008. The growing tillage intensity resulted in increased GHG emissions and undermined the GHG mitigation achievements from other activities or other sectors.

While nitrogen (N) and phosphorus (P) cycles have been investigated separately, the links between them are key for sustainable food systems. Combining material flow and ecological network analysis, this study examines the resilience of China’s N–P-coupled cycling network over time under different scenarios.

The exact quantification of environmental and human health gains achieved through sustainable nitrogen management is often impaired by real-world data availability. Drawing on an extensive database in China, this study estimates the costs and benefits of combining organic and chemical fertilizers, straw recycling and deep placement of fertilizer.

Sustainable phosphorus (P) management is central to food security and a healthy environment. This study quantifies the impacts of crop–livestock production on P use and losses at the sub-basin scale in China and evaluates the exceedance of a ‘safe’ and ‘just’ P planetary boundary.

China’s feed imports have a considerable environmental impact globally. This modelling study quantifies China’s potential protein self-sufficiency by simulating farming spatial relocation according to irrigation water and nitrogen surplus, as well as technological innovations and demand-side measures.

A trans-disciplinary framework shows how collaborative engagement and multi-phase development pathways can aid scaling up urban agriculture to transform food systems and support robust urban resilience and sustainability.

Whether, how and to what extent integrating crop production, livestock production and bioenergy systems can enhance the sustainability of specialized farming remains poorly understood at downscaled regional levels. This study quantifies life cycle impacts of agricultural integration in China, including bioenergy provision.

Livestock feed production competes directly or indirectly with food crops for natural resources. This study demonstrates that more efficient use of food system by-products in livestock diet can reduce feed–food competition, increase the global food supply and decrease the pressure on land and water resources.

Optimizing agricultural management practices has the potential to support sustainable agricultural intensification. This study presents a hybrid data-model integration approach that enables spatiotemporal optimization of agricultural management practices to maximize crop yield while reducing resource use and greenhouse gas emissions.

Global assessments of greenhouse gas emissions from nitrogen fertilizers show that production accounts for approximately one-third of total greenhouse gas emissions, with the remainder coming from the use phase. Intervention technologies at both the production and use phases could reduce up to 84% of global greenhouse gas emissions of synthetic nitrogen fertilizers by 2050.

Chinese agricultural production is key to achieve the country’s 2060 carbon neutrality target. Combining meta-analysis and life-cycle assessment, this study estimates the climate change mitigation potential of straw, biochar, and an integrated biomass pyrolysis and electricity generation system.

China is the global hotspot of ammonia emissions from croplands, with adverse impacts on human health and the environment. Reporting on a large-scale ammonia reduction trial at the county level in the North Plain China, this study shows that coordinated actions among smallholders can ensure high yields and improved air quality.

Organic nitrogen (N) sources management is critical to achieve high rice yield and carbon (C) neutrality. This study scaled up the field findings using machine learning and showed that the co-benefits of improved rice yield and reduced net C emission can be realized with integrated management of organic N and water on a global scale.