Foliar N O emissions constitute a significant source to atmosphere.

Nitrous oxide (N O) is a potent greenhouse gas and causes stratospheric ozone depletion. While the emissions of N O from soil are widely recognized, recent research has shown that terrestrial plants may also emit N O from their leaves under controlled laboratory conditions. However, it is unclear whether foliar N O emissions are universal across varying plant taxa, what the global significance of foliar N O emissions is, and how the foliage produces N O in situ.

Low-opportunity-cost feed can reduce land-use-related environmental impacts by about one-third in China.

Feeding animals more low-opportunity-cost feed products (LCFs), such as food waste and by-products, may decrease food-feed competition for cropland. Using a feed allocation optimization model that considers the availability of feed sources and animal requirements for protein and energy, we explored the perspectives of feeding more LCFs to animals in China. We found that about one-third of the animal feed consisted of human-edible products, while only 23% of the available LCFs were used as feed during 2009-2013.

Lower pork consumption and technological change in feed production can reduce the pork supply chain environmental footprint in China.

Nearly half of global pork production and consumption occurs in China, but the transition towards intensification is associated with worsening environmental impacts. Here we explore scenarios for implementing structural and technological changes across the pork supply chain to improve environmental sustainability and meet future demand. Following the middle-of-the-road socio-economic pathway (SSP2), we estimate that the environmental footprint from the pork supply chain will increase by ~50% from 2017 to 2050.

Integrating crop redistribution and improved management towards meeting China's food demand with lower environmental costs.

China feeds 19.1% of the world's population with 8.6% of the arable land.

Anthropogenic N input increases global warming potential by awakening the "sleeping" ancient C in deep critical zones.

Even a small net increase in soil organic carbon (SOC) mineralization will cause a substantial increase in the atmospheric CO concentration. It is widely recognized that the SOC mineralization within deep critical zones (2 to 12 m depth) is slower and much less influenced by anthropogenic disturbance when compared to that of surface soil. Here, we showed that 20 years of nitrogen (N) fertilization enriched a deep critical zone with nitrate, almost doubling the SOC mineralization rate.

Relocate 10 billion livestock to reduce harmful nitrogen pollution exposure for 90% of China's population.

Livestock production in China is increasingly located near urban areas, exposing human populations to nitrogen pollution via air and water. Here we analyse livestock and human population data across 2,300 Chinese counties to project the impact of alternative livestock distributions on nitrogen emissions. In 2012 almost half of China's livestock production occurred in peri-urban regions, exposing 60% of the Chinese population to ammonia emissions exceeding UN guidelines.

Cooperation between specialized livestock and crop farms can reduce environmental footprints and increase net profits in livestock production.

The rapid specialization of livestock production in China has contributed to spatially decoupled crop and livestock production, leading to various environmental pollution issues. Some regional agro-environmental policies have recently promoted the coupling of specialized crop and livestock farms through cooperation. However, the environmental and economic performances of such cooperation remain unclear.

Food and feed trade has greatly impacted global land and nitrogen use efficiencies over 1961-2017.

International trade of agricultural products has complicated and far-reaching impacts on land and nitrogen use efficiencies. We analysed the productivity of cropland and livestock and associated use of feed and fertilizer efficiency for over 240 countries, and estimated these countries' cumulative contributions to imports and exports of 190 agricultural products for the period 1961-2017. Crop trade has increased global land and partial fertilizer nitrogen productivities in terms of protein production, which equalled savings of 2,270 Mha cropland and 480 Tg synthetic fertilizer nitrogen over the analysed period.

Plants are a natural source of nitrous oxide even in field conditions as explained by N site preference.

Plants are either recognized to produce nitrous oxide (NO) or considered as a medium to transport soil-produced NO. To date, it is not clear whether in their habitat plants conduit NO produced in soil or are a natural source. We aimed to understand role of plants in NO emissions in field conditions.

Towards optimal use of phosphorus fertiliser.

Because phosphorus (P) is one of the most limiting nutrients in agricultural systems, P fertilisation is essential to feed the world. However, declining P reserves demand far more effective use of this crucial resource. Here, we use meta-analysis to synthesize yield responses to P fertilisation in grasslands, the most common type of agricultural land, to identify under which conditions P fertilisation is most effective.

Spatial Planning Needed to Drastically Reduce Nitrogen and Phosphorus Surpluses in China's Agriculture.

China's fertilization practices contribute greatly to the global biogeochemical nitrogen (N) and phosphorus (P) flows, which have exceeded the safe-operating space. Here, we quantified the potentials of improved nutrient management in the food chain and spatial planning of livestock farms on nutrient use efficiency and losses in China, using a nutrient flow model and detailed information on >2300 counties. Annual fertilizer use could be reduced by 26 Tg N and 6.

Benefits and trade-offs of replacing synthetic fertilizers by animal manures in crop production in China: A meta-analysis.

Recycling of livestock manure to agricultural land may reduce the use of synthetic fertilizer and thereby enhance the sustainability of food production. However, the effects of substitution of fertilizer by manure on crop yield, nitrogen use efficiency (NUE), and emissions of ammonia (NH ), nitrous oxide (N O) and methane (CH ) as function of soil and manure properties, experimental duration and application strategies have not been quantified systematically and convincingly yet. Here, we present a meta-analysis of these effects using results of 143 published studies in China.

Nitrogen Surplus Benchmarks for Controlling N Pollution in the Main Cropping Systems of China.

Nitrogen (N) surplus is a useful indicator for improving agricultural N management and controlling N pollution. Few studies have developed benchmark values for cropping systems in China, a country with the largest N fertilizer use in the world. We established N surplus benchmarks for 13 main cropping systems, at optimal N management, using results from >4500 on-farm field experiments and a soil surface balance approach.

Fertile cities: Nutrient management practices in urban agriculture.

Cities are increasingly targeted as centers for sustainable development and innovation of food systems. Urban agriculture (UA) is advocated by some as a multi-faceted approach to help achieve urban sustainability goals as it provides possible social, economic and environmental benefits. The role of UA in restoring resource cycles receives increasing attention, especially with regard to assimilating urban waste.

Exploring Future Food Provision Scenarios for China.

Developing sustainable food systems is essential, especially for emerging economies, where food systems are changing rapidly and affect the environment and natural resources. We explored possible future pathways for a sustainable food system in China, using multiple environmental indicators linked to eight of the Sustainable Development Goals (SDGs). Forecasts for 2030 in a business as usual scenario (BAU) indicate increases in animal food consumption as well as increased shortages of the land available and the water needed to produce the required food in China.

Irrigation reduces the negative effect of global warming on winter wheat yield and greenhouse gas intensity.

Global warming may exacerbate drought, decrease crop yield and affect greenhouse gas (GHG) emissions in semi-arid regions. However, the interactive effects of increases in temperature and water availability on winter wheat yield and GHG emissions in semi-arid climates are not well-understood. Here, we report on a two-year field experiment that examined the effects of a mean soil temperature increase of ~2 °C (at 5 cm depth) with and without additional irrigation on wheat yield and GHG emissions.

China's livestock transition: Driving forces, impacts, and consequences.

China's livestock industry has experienced a vast transition during the last three decades, with profound effects on domestic and global food provision, resource use, nitrogen and phosphorus losses, and greenhouse gas (GHG) emissions. We provide a comprehensive analysis of the driving forces around this transition and its national and global consequences. The number of livestock units (LUs) tripled in China in less than 30 years, mainly through the growth of landless industrial livestock production systems and the increase in monogastric livestock (from 62 to 74% of total LUs).

Global environmental costs of China's thirst for milk.

China has an ever-increasing thirst for milk, with a predicted 3.2-fold increase in demand by 2050 compared to the production level in 2010. What are the environmental implications of meeting this demand, and what is the preferred pathway? We addressed these questions by using a nexus approach, to examine the interdependencies of increasing milk consumption in China by 2050 and its global impacts, under different scenarios of domestic milk production and importation.

Balanced N and C input recommendations for rain-fed maize production in northern China based on N balances and grain yields.

Background: This study aimed to assess longer-term (1993-2009) effects of combined applications of fertiliser, maize stover, and cattle manure on maize yields, partial nitrogen (N) and carbon (C) balances, and water and N-use efficiencies, to guide N and C input recommendations for rain-fed maize production in northern China.

Results: The field trial, with three factors at five levels and 12 treatments, was conducted at Shouyang Dryland-Farming Experimental Station, Shanxi, China. Data analysis revealed higher N balances but lower C balances significantly occurred in a dry year than in a wet year.