Measurement of soil nitrogen is important for optimizing use of nitrogen fertilization and variable-rate fertilization, but is not performed regularly. Rather, farmers often rely on advice from governments, suppliers and peers when deciding the economically optimal amount of fertilizer to use for crop yields. Ensuing overuse of nitrogen fertilizer has negative environmental impacts, including chemically degraded arable land, eutrophication of surface water and apparent shifts in the make-up of microbial communities in soil. An electrical point-of-use sensor to determine soil NH4 + with a large dynamic range, costing less than US$0.10 per module, has been developed. Using data on soil dynamics from soil pot experiments conducted under eight sets of environmental conditions, a machine learning model was developed to predict the level of NO3 – in soil instantaneously, and future levels of both NH4 + and NO3 –. This work has the potential to inform growers of immediate soil nutrient needs and facilitate, with greater precision, future fertilization plans.

See Grell et al.

Resilience is the capacity to recover in response to adverse circumstances, and resilient food systems are needed in the face of population growth and the impacts of climate change. Resilience of food systems has economic, social and ecological facets characterized by financial equitability, inclusivity and support of communities, and minimization of detriment to the natural environment. A central theme emerged for the scientists working on the UN Food Systems Summit Action Track on Resilience, and that was diversification. Diversification supports resilience, and there are multiple opportunities to enhance diversification along the supply chain, including at the production level, the global, regional and local trading systems level, and at the household level.

See Hertel et al.

Top-down approaches of assessing food security and land-use change use crop models and gridded spatial frameworks to organize data on climate, soil and cropping systems. Bottom-up approaches use data on weather, soil and cropping systems measured at sites explicitly chosen as representative for upscaling estimates for the crop production area. Comparing top-down approaches, the Global Agro-ecological Zones (GAEZ) model and the median of the model ensemble of the Agricultural Model Intercomparison and Improvement Project (AgMIP) with the bottom-up approach of the Global Yield Gap Atlas (GYGA), estimates of production were shown to reconcile poorly, providing different prognoses regarding cereal self-sufficiency. Incorporating bottom-up into top-down approaches could reduce uncertainty.

SeeEdreira et al.

Current market prices reflect only a small share of the true cost of food. Most of the social, environmental and human impacts of food production, processing, distribution and consumption are not economically valued and end up neglected in decision-making. True cost accounting is a promising strategy to evince some of these impacts and internalize food-related externalities along the supply chain, thereby contributing to the promotion of a more sustainable food system.

See Editorial, Kurtz, Patel, Richardson, Lord et al. and de Adelhart Toorop et al.

Food security is commonly analysed on the basis of mean climate change estimates, however droughts and floods are expected to become more frequent and intense in the near future. Relative to median-level climate change, an additional 20–36% and 11–33% of the world population may face hunger by 2050 under high and low greenhouse gas emission scenarios, respectively. In some affected regions such as South Asia, the amount of additional food requirement to offset such effect is triple the region’s current food storage.

See Hasegawa et al.

The COVID-19 pandemic has exacerbated crises in health and food systems, pushing millions into food insecurity and malnutrition. In low- and middle-income countries, disruptions related to COVID-19 could precipitate an additional 9.3 million cases of childhood wasting, 2.6 million cases of childhood stunting, and an additional 168,000 childhood deaths due to poor nutrition by 2022. The cost of scaling up nutrition to mitigate these effects is estimated at US$1.2 billion per year.

See Osendarp et al.

Managing light quantity and quality for photosynthesis are avenues for improving crop yield. A passive approach involves using a reflector-free, spectral-shifting microphotonic thin film to serve as a greenhouse envelope, converting the impinging sunlight to more photosynthetically active red light. The film of the red-coloured greenhouse augments lettuce production by about 20% under conditions of full-spectrum grow lights or in facilities with just natural sunlight.

See Shen et al.

Insecticide exposure is a key global driver of pollinator declines. Organophosphates, which account for more than a third of insecticide sales worldwide are highly toxic to pollinators. Utilizing the capability of phosphotriesterase enzymes to hydrolase linkages in organophosphates, it may be possible to develop in vivo detoxification systems for managed pollinators. Microcolonies of bumblebees fed pollen patties contaminated with malathion, the widely applied organophosphate pesticide, demonstrated 100% survival when also fed with phosphotriesterase-encapsulated pollen-inspired microparticles. Pollen-mimicking, enzyme-loaded microparticles may have potential to be deployed at low cost and large scale, incorporated into supplemental feeds, to detoxify organophosphate insecticides in stored nectar and pollen.

See Chen et al.

Production of soybean and corn in Brazil has increased four-fold since 1980 and the country is now the world’s largest and second largest exporter of each, respectively. The grain boom has been driven by cropland expansion and double cropping. Municipality-level data shows that cropland expansion has been the predominant strategy in frontier regions, such as the Centre-West and Matopiba, and has received attention as Brazil’s agricultural system evolves. However, double cropping, which predominates in conventional agricultural regions such as the south, has offset the equivalent of 76.7 Mha of arable land for grain production from 2003 to 2016, and has had increased impacts over land expansion. The experience of Brazil in double cropping may be valuable for pan-tropical countries producing grain for global trade.

See Xu et al.

Network medicine utilizes the power of data science to explore functionally relevant cellular interactions in the progression of disease, offering insights for the development of improved pharmaceutical targets. Polyphenols are phytochemicals found across a variety of food sources and though their health benefits, particularly in protection against non-communicable chronic disease, are increasingly observed in epidemiology, the molecular mechanisms by which these benefits are conferred are poorly established. A network medicine framework allows the cellular interconnectedness of polyphenol protein targets and proteins associated with disease to be explored. The network proximity of these target and disease neighbours of the human interactome is shown to be predictive of therapeutic effects of polyphenols.

See do Valle et al.

Climate projections to 2100 indicate that the length and frequency of dangerous heat-stress events will increase, meaning livestock producers in East Africa — and their animals — will need to adapt to these climate-induced events to avoid production losses. Swine and poultry will suffer the greatest production losses in the region, but goat or sheep offer more resilient options for livestock producers. Switching to more heat-stress-tolerant breeds may provide alternative solutions, particularly in extensive farming systems. Dangerous heat-stress events will affect intensive production systems, despite the potential for technological interventions and climate control.

See Rahimi et al.

A systematic understanding of the linkages between crop diversity, agricultural management and environmental factors such as climatic conditions and soil properties is key to the design of sustainable cropping systems. For 155 cereal fields with a high range of crop diversities across a 3,000-km north–south European gradient, the proportion of time with crop cover, regardless of its diversity, had a significantly positive impact on soil bacterial diversity, soil multifunctionality and crop yields. Increasing the proportion of time with crop cover, instead of increasing crop diversity within the rotation, could be a better approach to enhancing both yields and soil functioning, while providing habitat for soil microorganisms in European cropping systems.

See Garland et al.