• China is the largest producer of pomelo globally.

Pomelo is a member of the genus Citrus that is a key contributor to the breeding of modern citrus cultivars. China is the largest producer of pomelo and one of the top five pomelo exporting countries. Pomelos from Thailand are also well-known for their excellent quality and flavor and are ranked in the top ten export countries. This review introduces pomelo planting locations and conditions in China and Thailand. The characteristics and qualities of some commercial pomelo cultivars in China and Thailand are summarized to introduce them to international consumers and to document their similarities and dissimilarities. Data on bioactive compounds and antioxidant capacity are also included for most Chinese and Thai pomelos to highlight how they differ in this aspect because consumers are increasingly interested in healthier foods. In addition, the sensory perception in terms of aroma, flavor, texture and taste attributes and consumer perspective and preferences are discussed.

● Simultaneous H₂S and CO₂ removal from biogas is studied.

Upgrading biogas into biomethane not only improves the biogas utilization as vehicle fuel or natural gas substitute, but also reduces the greenhouse gases emissions. Considering the principle of engineering green energy process, the renewable aqueous ammonia (RAA) solution obtained from biogas slurry was used to remove H₂S and CO₂ simultaneously in the hollow fiber membrane contactor. RAA was mimicked in this study using the ammonia aqueous solution mixed with some typical impurities including ethanol, acetic acid, propionic acid, butyric acid and NH₄HCO₃. Compared with the typical physical absorption (i.e., pure water) removing 48% of H₂S from biogas, RAA with 0.1 mol·L⁻¹ NH₃ could remove 97% of H₂S. Increasing the NH₃ concentration from 0.1 to 0.5 mol·L⁻¹ could elevate the CO₂ absorption flux from 0.97 to 1.72 mol·m⁻²·h⁻¹ by 77.3%. Among the impurities contained in RAA, ethanol has a less impact on CO₂ absorption, while other impurities like CO₂ and acetic acid have significant negative impacts on CO₂ absorption. Fortunately, the impurities have a less influence on H₂S removal efficiency, with more than 98% of H₂S could be removed by RAA. Also, the influences of operating parameters on acid gases removal were investigated to provide some engineering suggestions.

● A composite N management index is proposed to measure agriculture sustainability.

To represent the sustainability of nitrogen management in the Sustainable Development Goals indicator framework, this paper proposes a sustainable nitrogen management index (SNMI). This index combines the performance in N crop yield and N use efficiency (NUE), thereby accounting for the need for both food production and environmental protection. Applying SNMI to countries around the world, the results showed improvement in the overall sustainability of crop N management over the past four decades, but this improvement has been mainly achieved by crop yield increase, while global NUE has improved only slightly. SNMI values vary largely among countries, and this variation has increased since the 1970s, implying different levels of success, even failure, in improving N management for countries around the world. In the standard SNMI assessment, the reference NUE was defined as 1.0 (considered an ideal NUE) and the reference yield was defined as 90 kg·ha⁻¹·yr⁻¹ N (considering a globally averaged yield target for meeting food demand in 2050). A sensitivity test that replaced the reference NUE of 1.0 with more realistic NUE targets of 0.8 or 0.9 showed overall reduction in SNMI values (i.e., improved performance), but little change in the ranking among countries. In another test that replaced the universal reference yield with region-specific attainable yield, SNMI values declined (i.e., improved performance) for most countries in Africa and West Asia, whereas they increased for many countries in Europe and South America. The index can be improved by further investigation of approaches for setting region-specific yield targets and high-quality data on crop yield potentials. Overall, SNMI offers promise for a simple and transparent approach to assess progress of countries toward sustainable N management with a single indicator.

● Either increasing C input to or reducing C release from soils can enhance soil C sequestration.

Climate change vigorously threats human livelihoods, places and biodiversity. To lock atmospheric CO₂ up through biological, chemical and physical processes is one of the pathways to mitigate climate change. Agricultural soils have a significant carbon sink capacity. Soil carbon sequestration (SCS) can be accelerated through appropriate changes in land use and agricultural practices. There have been various meta-analyses performed by combining data sets to interpret the influences of some methods on SCS rates or stocks. The objectives of this study were: (1) to update SCS capacity with different land-based techniques based on the latest publications, and (2) to discuss complexity to assess the impacts of the techniques on soil carbon accumulation. This review shows that afforestation and reforestation are slow processes but have great potential for improving SCS. Among agricultural practices, adding organic matter is an efficient way to sequester carbon in soils. Any practice that helps plant increase C fixation can increase soil carbon stock by increasing residues, dead root material and root exudates. Among the improved livestock grazing management practices, reseeding grasses seems to have the highest SCS rate.

• A relative yield of 70% was obtained under both border and drip irrigation.

Agriculture faces the dual challenges of food security and environmental sustainability. Here, we investigate current maize production at the field scale, analyze the yield gaps and impacting factors, and recommend measures for sustainably closing yield gaps. An experiment was conducted on a 3.9-ha maize seed production field in arid north-western China, managed with border and drip irrigation, respectively, in 2015 and 2016. The relative yield reached 70% in both years. However, drip irrigation saved 227 mm irrigation water during a drier growing season compared with traditional border irrigation, accounting for 44% of the maize evapotranspiration (ET). Yield variability under drip irrigation was 12.1%, lower than the 18.8% under border irrigation. Boundary line analysis indicates that a relative yield increase of 8% to 10% might be obtained by optimizing the yield-limiting factors. Plant density and soil available water content and available nitrogen were the three major factors involved. In conclusion, closing yield gaps with agricultural sustainability may be realized by optimizing agronomic, irrigation and fertilizer management, using water-saving irrigation methods and using site-specific management.

• Historic trends in nutrient loading and flux in the Yangtze River were analyzed

Intensifying human activity in the Yangtze River basin has substantially increased nutrient concentrations in the Yangtze River Estuary, leading to degradation of the coastal environment. Analysis of nutrient determinations published over the past 50 years reveals a gradual decreasing trend in the concentrations and fluxes of dissolved silicate (DSi). However, both dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphate (DIP) concentrations have increased significantly since the 1970s. The frequency of and area covered by red tide outbreaks have increased greatly during this period, mainly due to changes in nutrient supply ratios [i.e., N/P (DIN/DIP), N/Si (DIN/DSi), P/Si (DIP/DSi)]. A strong correlation was found between the riverine DIN fluxes and the estimated DIN inputs from the major N sources, particularly fertilizers and atmospheric deposition. The data provide a comprehensive assessment of nutrients in the Yangtze River basin and their ecological impacts and indicate a potentially significant influence of atmospheric deposition on DIN loadings and fluxes.

• The dynamic interplay between phytohormones plays an important part in climacteric fruit ripening.

Fruit ripening is a complex developmental process made up of genetically programmed physiological and biochemical activities. It culminates in desirable changes in the structural and textural properties and is governed by a complex regulatory network. Much is known about ethylene, one of the most important metabolites promoting the ripening of climacteric fruits. However, the dynamic interplay between phytohormones also plays an important part. Additional regulatory factors such as transcription factors (TFs) and epigenetic modifications also play vital role in the regulation of climacteric fruit ripening. Here, we review and evaluate the complex regulatory network comprising interactions between hormones and the action of TFs and epigenetic modifications during climacteric fruit ripening.

•Agricultural green transformation of China requires restructuring of cropping systems.

Intensive agriculture in China over recent decades has successfully realized food security but at the expense of negative environmental impacts. Achieving green transformation of agriculture in China requires fundamental restructuring of cropping systems. This paper presents a theoretical framework of theory, approaches and implementation of crop diversification schemes in China. Initially, crop diversification schemes require identifying multiple objectives by simultaneously considering natural resources, limiting factors/constraints, and social and economic demands of different stakeholders. Then, it is necessary to optimize existing and/or design novel cropping systems based upon farming practices and ecological principles, and to strengthen targeted ecosystem services to achieve the identified objectives. Next, the resulting diversified cropping systems need to be evaluated and examined by employing experimental and modeling approaches. Finally, a strategic plan, as presented in this paper, is needed for implementing an optimized crop diversification in China based upon regional characteristics with the concurrent objectives of safe, nutritious food production and environmental protection. The North China Plain is used as an example to illustrate the strategic plan to optimize and design diversified cropping systems. The implementation of crop diversification in China will set an example for other countries undergoing agricultural transition, and contribute to global sustainable development.

● The source and sink status of ditches and ponds was studied in an upland area in the Jinglinxi catchment, China.

As the common features of agroecosystems, ditches and ponds benefit the irrigation and drainage, as well as intercepting non-point source pollutants. However, most ditch-pond studies have been conducted in lowland areas. To test this source-sink assumption in upland areas, this study made observations on the ecological function of the ditch and pond system in a typical catchment in China. First, the changes in ponds in the catchment were analyzed using high-resolution remote sensing data. Then, the migration of agricultural pollutants in ditches and ponds were analyzed by field sampling and laboratory detection. The results showed that over the past 15 years the length of ditches in the catchment and the number of small ponds (< 500 m²) have increased by 32% and 75%, respectively. The rate of change in nutrient concentrations in the ditches and ponds were mostly from −20% to 20%, indicating ditches and ponds can be both sources and sinks for agricultural pollutants. Lastly, the contributing factors were explored and it was found that ditches and ponds are important sinks in dry season. However, during the rainy season, ditches and ponds become sources of pollutants, with the rapid drainage of ditches and the overflow of ponds in upland areas. The results of this study revealed that the ditches and ponds could be used for ecological engineering in upland catchments to balance drainage and intercept pollutants.

● Arable-ley rotations can alleviate soil degradation and erosion.

Agricultural intensification and the subsequent decline of mixed farming systems has led to an increase in continuous cropping with only a few fallow or break years, undermining global soil health. Arable-ley rotations incorporating temporary pastures (leys) lasting 1–4 years may alleviate soil degradation by building soil fertility and improving soil structure. However, the majority of previous research on arable-ley rotations has utilized either grass or grass-clover leys within ungrazed systems. Multispecies leys, containing a mix of grasses, legumes, and herbs, are rapidly gaining popularity due to their promotion in agri-environment schemes and potential to deliver greater ecosystem services than conventional grass or grass-clover leys. Livestock grazing in arable-ley rotations may increase the economic resilience of these systems, despite limited research of the effects of multispecies leys on ruminant health and greenhouse gas emissions. This review aims to evaluate previous research on multispecies leys, highlighting areas for future research and the potential benefits and disbenefits on soil quality and livestock productivity. The botanical composition of multispecies leys is crucial, as legumes, deep rooted perennial plants (e.g., Onobrychis viciifolia and Cichorium intybus) and herbs (e.g., Plantago lanceolata) can increase soil carbon, improve soil structure, reduce nitrogen fertilizer requirements, and promote the recovery of soil fauna (e.g., earthworms) in degraded arable soils while delivering additional environmental benefits (e.g., biological nitrification inhibition and enteric methane reduction). Multispecies leys have the potential to deliver biologically driven regenerative agriculture, but more long-term research is needed to underpin evidence-based policy and farmer guidance.

• Metabolites of fresh tea shoots at harvest were profiled.

Metabolites, especially secondary metabolites, are very important in the adaption of tea plants and the quality of tea products. Here, we focus on the seasonal variation in metabolites of fresh tea shoots and their regulatory mechanism at the transcriptional level. The metabolic profiles of fresh tea shoots of 10 tea accessions collected in spring, summer, and autumn were analyzed using ultra-performance liquid chromatography coupled with quadrupole-obitrap mass spectrometry. We focused on the metabolites and key genes in the phenylpropanoid/flavonoid pathway integrated with transcriptome analysis. Multivariate statistical analysis indicates that metabolites were distinctly different with seasonal alternation. Flavonoids, amino acids, organic acids and alkaloids were the predominant metabolites. Levels of most key genes and downstream compounds in the flavonoid pathway were lowest in spring but the catechin quality index was highest in spring. The regulatory pathway was explored by constructing a metabolite correlation network and a weighted gene co-expression network.

● Crop pests are a major factor restricting agricultural production in China.

The importance of food security, especially in combating the problem of acute hunger, has been underscored as a key component of sustainable development. Considering the major challenge of rapidly increasing demands for both food security and safety, the management and control of major pests is urged to secure supplies of major agricultural products. However, owing to global climate change, biological invasion (e.g., fall armyworm), decreasing agricultural biodiversity, and other factors, a wide range of crop pest outbreaks are becoming more frequent and serious, making China, one of the world’s largest country in terms of agricultural production, one of the primary victims of crop yield loss and the largest pesticide consumer in the world. Nevertheless, the use of science and technology in monitoring and early warning of major crop pests provides better pest management and acts as a fundamental part of an integrated plant protection strategy to achieve the goal of sustainable development of agriculture. This review summarizes the most fundamental information on pest monitoring and early warning in China by documenting the developmental history of research and application, Chinese laws and regulations related to plant protection, and the National Monitoring and Early Warning System, with the purpose of presenting the Chinese model as an example of how to promote regional management of crop pests, especially of cross border pests such as fall armyworm and locust, by international cooperation across pest-related countries.

● Investigate the actual situation of food waste at university canteens in Beijing, China.

Food waste is a major social problem that contributes to the overutilization of natural resources, affecting economic progress and environmental protection. Food waste occurs throughout the whole process of the food supply chain, especially during the consumption stage. As a special group of consumers, the emerging adults at university may have unique food consumption patterns and their food waste behavior in university canteens deserves more attention. To understand the influential factors of the food-waste behavior of students in university canteens, a field survey was conducted at China Agricultural University canteen with 705 respondents. Based on the theory of planned behavior, this paper examines the influencing factors of student food-waste behavior from three dimensions: sociopsychological factors, individual characteristics and dining factors. The results indicate that the percentage of students who waste food is relatively low, at roughly 27%. Perceived behavior control, gender, monthly living expenses, BMI, mealtime, meal expectations and food portion were significantly correlated with student food-waste behavior, among which perceived behavior control had the most prominent correlation, followed by food portion. Behavioral intention, household location and palatability were not significantly correlated with student food-waste behavior. Therefore, it is necessary to promote publicity and education on reducing food waste on campus, reinforce the administration of the department of support service, and optimize the food portion in the canteen.

● Promotion of local sustainable innovation developed by forest farmers.

Adopting community-based innovations in agroforestry is key to enhancing livelihoods in forest farmer communities. This research aimed to explore the perceived advantages of the forest farmer technique of coffee branch bending to overcome the light limitations under the shade of a pine forest. The concepts of perceived characteristics of innovation were used to explore the advantages of this technique. Using a case study of an exclusive forest farmer clique in UB (University of Brawijaya) Forest in Indonesia, it was found that the local technique had high perceived relative advantages. Compared to the others, the bending technique increases coffee production and is easy to do. It was also found to be superior to reducing production costs and is perceived as more environmentally friendly, promoting it as a valuable sustainable practice. Technical experts need to validate it and may embrace it as a co-innovation for the available external agroforestry recommendations. Its adaptability to the local socio-ecological context and techno-economical constraints makes it a prospective innovation to be extended through social forestry programs.

● Shifting from the existing dietary patterns to the alternative recommended dietary pattern could enhance the sustainable development of environment and human health.

With the rapid development of China’s economy, Chinese people tend to eat foods rich in fat, sugar and protein. This change in dietary pattern has brought double challenges to China’s sustainable development of environment and human health. So it has become urgent for the nation to shift to a healthy and sustainable dietary pattern. Based on the China Health and Nutrition Survey database, this study used K-means cluster analysis to classify China’s existing dietary patterns into quasi-southern, quasi-northern and quasi-western patterns. Two alternative recommended dietary patterns, Chinese dietary and planet health patterns, were selected to compare the effects of environment and health. The results show that a shift from the three existing dietary patterns to two alternative dietary patterns could enhance sustainable development of environment, especially for the quasi-western pattern shifting to the planet health pattern. Also, a shift would have of great benefits for human health, effectively reduce the relative risks of diseases such as hypertension, type 2 diabetes and coronary heart disease. The greatest benefits would come from shifting the quasi-western pattern benefits to one of the two alternative dietary patterns in terms of environment effects, and the quasi-southern pattern benefits most in terms of health effects. Shifting to the planet health pattern is more effective than the Chinese dietary pattern both in environment and human health. This paper provides policy recommendations to vigorously advocate dietary balance, scientifically promote dietary patterns, and change consumer dietary behavior.

● Progress on nitrogen management in agriculture is overviewed in China.

Since the 1980s, the widespread use of N fertilizer has not only resulted in a strong increase in agricultural productivity but also caused a number of environmental problems, induced by excess reactive N emissions. A range of approaches to improve N management for increased agricultural production together with reduced environmental impacts has been proposed. The 4R principles (right product, right amount, right time and right place) for N fertilizer application have been essential for improving crop productivity and N use efficiency while reducing N losses. For example, site-specific N management (as part of 4R practice) reduced N fertilizer use by 32% and increased yield by 5% in China. However, it has not been enough to overcome the challenge of producing more food with reduced impact on the environment and health. This paper proposes a new framework of food-chain-nitrogen-management (FCNM). This involves good N management including the recycling of organic manures, optimized crop and animal production and improved human diets, with the aim of maximizing resource use efficiency and minimizing environmental emissions. FCNM could meet future challenges for food demand, resource sustainability and environmental safety, key issues for green agricultural transformation in China and other countries.

● Matching nitrification inhibitors with soil properties and nitrifiers is vital to achieve a higher NUE.

Soil microbiomes drive the biogeochemical cycling of nitrogen and regulate soil N supply and loss, thus, pivotal nitrogen use efficiency (NUE). Meanwhile, there is an increasing awareness that plant associated microbiomes and soil food web interactions is vital for modulating crop productivity and N uptake. The rapid advances in modern omics-based techniques and biotechnologies make it possible to manipulate soil-plant microbiomes for improving NUE and reducing N environmental impacts. This paper summarizes current progress in research on regulating soil microbial N cycle processes for NUE improvement, plant-microbe interactions benefiting plant N uptake, and the importance of soil microbiomes in promoting soil health and crop productivity. We also proposes a potential holistic (rhizosphere-root-phyllosphere) microbe-based approach to improve NUE and reduce dependence on mineral N fertilizer in agroecosystems, toward nature-based solution for nutrient management in intensive cropping systems.

● To achieve food security, Chinese agriculture– food system could not achieve C neutrality.

The agricultural sector, a major source of greenhouse gas emissions, and emissions from agriculture must be reduced substantially to achieve carbon (C) neutrality. Based on a literature analysis and other research results, this study investigated the effects and prospects of C reduction in agricultural systems under different scenarios (i.e., methods and approaches) in the context of China’s dual C goals, as those working in the agricultural sector have yet to reach a consensus on how to move forward. Different views, standards, and countermeasures were analyzed to provide a reference for agricultural action supporting China’s C neutrality goal.

● Soil nitrogen fluxes and influencing factors were reviewed in the subtropical hilly regions.

The subtropical hilly region of China is a region with intensive crop and livestock production, which has resulted in serious N pollution in soil, water and air. This review summarizes the major soil N cycling processes and their influencing factors in rice paddies and uplands in the subtropical hilly region of China. The major N cycling processes include the N fertilizer application in croplands, atmospheric N deposition, biological N fixation, crop N uptake, ammonia volatilization, N₂O/NO emissions, nitrogen runoff and leaching losses. The catchment nutrients management model for N cycle modeling and its case studies in the subtropical hilly region were also introduced. Finally, N management practices for improving N use efficiency in cropland, as well as catchment scales are summarized.

•Wide use of botanical insecticides is limited by the availability of certain plants.

Bioinsecticides are naturally-occurring substances from different sources that control insect pests. Ideal bioinsecticides should have low toxicity to non-target organisms. They should also be easily degraded in sewage treatment works and natural environments, highly effective in small quantities and affect target pests only. Public concerns about possible side-effects of synthetic pesticides have accelerated bioinsecticide research and development. However, to develop bioinsecticides into mainstream products, their high production costs, short shelf-life and often uncertain modes of action need to be considered. This review summarizes current progress on bioinsecticides which are categorized as biochemical insecticides and their derivatives, plant-incorporated protectants, and microbial bioinsecticides. The current constraints that prevent bioinsecticides from being widely used are discussed and future research directions are proposed.

● The analysis of financing for the transformation of food systems requires first a consideration of costs.

The paper provides a review of the work on financing the transformation of food systems done by the author and colleagues at IFPRI. The analysis discusses the objectives of that transformation (related to the Sustainable Development Goals and the Paris Agreement) and shows estimates of the costs involved. Then it presents an evaluation of the existing financial flows and their potential scaling up, using a broader view of six main flows involved: two that are internal to food systems (consumer expenditures on food and related items, which are the main source of revenue (as sales) for the variety of actors on the supply side of food systems); and four that are external (international development funds, public budgets, banking systems, and capital markets). The paper notes that although current funding does not reach the scale needed to finance the desired transformation of food systems, there are sufficient potential financial resources available in the aggregate to achieve such transformation. However, to mobilize the existing potential funds the paper discussed several things that need to be done, starting with an adequate macroeconomic and overall incentive framework to guide both the internal flows related to consumption and production decisions, as well as the four external ones. The paper also suggested other possible interventions to mobilize, reorient, and increase the financial flows to the desired objectives. It further noted that the costs and financing, which in the paper were discussed at the global level, must be estimated at the country level, as part of the design and implementation of adequate national plans for equitable, healthy and sustainable food systems.

● Establishment of a rapid tool for monitoring soil carbon sequestration in farmer fields.

In 2015, 17 Sustainable Development Goals (SDGs) were approved, including SDG13, which addresses actions to increase carbon capture (CO₂-C storage) for climate change mitigation. However, no analytical procedures have been defined for quantifying soil organic carbon (SOC) sequestration. This paper presents a rapid tool for guiding farmers and for monitoring SOC sequestration in farmer fields. The tool consists of multiconstituent soil analyses through near-infrared spectroscopy (NIRS) and an SOC mineralization model. The tool provides forecasts of SOC sequestration over time. Soil analyses by NIRS have been calibrated and validated for farmer fields in European countries, China, New Zealand, and Vietnam. Results indicate a high accuracy of determination for SOC (R²≥ 0.93), and for inorganic C, soil texture, and soil bulk density. Permanganate oxidizable soil C is used as proxy for active SOC, to detect early management-induced changes in SOC contents, and is also quantified by NIRS (R² = 0.92). A pedotransfer function is used to convert the results of the soil analyses to SOC sequestration in kg·ha⁻¹ C as well as CO₂. In conclusion, the tool allows fast, quantitative, and action-driven monitoring of SOC sequestration in farmer fields, and thereby is an essential tool for monitoring progress of SDG13.

● The choice of a modern agriculture project was found to be rational for professional farmers to reduce interference from non-market factors. The success of this project is due to its capacity to successfully fill the structural hole in the market transaction network.

A comparative multi-case analysis of professional farmer entrepreneurship cases in China was performed by applying the structural hole theory. The results confirmed four views. (1) Choosing the modern agriculture project entrepreneurship is rational for professional farmers, who return from urban, to reduce the interference from non-market factors. The success of this project stems from its ability to successfully occupy the structural hole of the market trading network. (2) In economically developed areas, professional farmers start their businesses and reduce transaction costs with factors by occupying ‘self-benefit’ or ‘mutual-benefit’ structural holes in market networks. (3) In traditional agricultural areas, for reducing factor transaction costs, professional farmers occupy the organizational-governance structural hole of rural social relationship networks and the mutual-benefit structural hole of market networks to start their businesses. (4) The embedding order of these two structural holes will change depending on the differences in the local resource endowment. This article proposes some suggestions to encourage professional farmers to develop featured agricultural projects, build a close benefit-linked mechanism with smallholders through the provision of socialized services, and participate in the governance of rural communities.

● The Green Revolution broadened the trade-off between yield and nitrogen-use efficiency.

The Green Revolution of the 1960s boosted crop yields in part through widespread production of semidwarf plant cultivars and extensive use of mineral fertilizers. The beneficial semidwarfism of cereal Green Revolution cultivars is due to the accumulation of plant growth-repressing DELLA proteins, which increases lodging resistance but requires a high-nitrogen fertilizer to obtain high yield. Given that environmentally degrading fertilizer use underpins current worldwide crop production, future agricultural sustainability needs a sustainable Green Revolution through reducing N fertilizer use while boosting grain yield above what is currently achievable. Despite a great deal of research efforts, only a few genes have been demonstrated to improve N-use efficiency in crops. The molecular mechanisms underlying the coordination between plant growth and N metabolism is still not fully understood, thus preventing significant improvement. Recent advances of how plants sense, capture and respond to varying N supply in model plants have shed light on how to improve sustainable productivity in agriculture. This review focuses on the current understanding of root developmental and metabolic adaptations to N availability, and discuss the potential approaches to improve N-use efficiency in high-yielding cereal crops.

● An expert survey highlighted the most effective strategies for GHG and ammonia mitigation.

Agriculture is essential for providing food and maintaining food security while concurrently delivering multiple other ecosystem services. However, agricultural systems are generally a net source of greenhouse gases and ammonia. They, therefore, need to substantively contribute to climate change mitigation and net zero ambitions. It is widely acknowledged that there is a need to further reduce and mitigate emissions across sectors, including agriculture to address the climate emergency and emissions gap. This discussion paper outlines a collation of opinions from a range of experts within agricultural research and advisory roles following a greenhouse gas and ammonia emission mitigation workshop held in the UK in March 2022. The meeting identified the top mitigation priorities within the UK’s agricultural sector to achieve reductions in greenhouse gases and ammonia that are compatible with policy targets. In addition, experts provided an overview of what they believe are the key knowledge gaps, future opportunities and co-benefits to mitigation practices as well as indicating the potential barriers to uptake for mitigation scenarios discussed.

● LFD was treated by fly ash-based chemical precipitation and CO₂ mineralization.

Chemical precipitation is a widely applied approach for a liquid fraction of digestate (LFD) of agricultural waste but its large-scale application requires low-cost and efficient precipitating agents and novel process design. This study evaluated novel approach for the efficient removal of contaminants from the LFD using fly ash-based chemical precipitation, followed by filtration and CO₂ mineralization. The technical feasibility of this approach was evaluated using pH and electrical conductivity (EC), and removal efficiencies of total phosphorus (TP), chemical oxygen demand (COD) and heavy metals during the treatment. The fly ash used in this study showed a promising performance as a chemical precipitation agent for COD and TP removal from the treated LFD involving complex effects of precipitation and adsorption. CO₂ bubbling after fly ash-based chemical precipitation provided further COD and TP removal by carbonation reactions between CO₂ and the excessive alkaline minerals in fly ash. Although addition of fly ash to untreated LFD increased pH from 8.3 to 12.9 and EC from 7.01 to 13.7 mS·cm⁻¹, CO₂ bubbling helped neutralize the treated LFD and reduce the EC, and concentrations of toxic ions by carbonation reactions. The fly ash-based chemical precipitation and CO₂ mineralization had > 93% COD and > 98% TP removal efficiencies, and resulted in an EC of < 2 mS·cm⁻¹ and a neutral pH in the treated LFD, as well as the high purity calcite product.

● Food systems in East and Southeast Asia are vulnerable to global warming.

Food system resilience to climate change is uniquely imperative for bringing Sustainable Development Goals within reach and leaving no one behind. Food systems in East and Southeast Asia are interacting with planetary boundaries and are adversely affected by extreme weather-related events. A practical question for East and Southeast Asian stakeholders is how to foster climate-resilient food systems in the face of lingering food system vulnerabilities and policy gaps. This paper reviews food system vulnerabilities and policy responses to climate change. In the policy-based review, this paper compares the economy-wide and agriculture-specific targets of low-carbon development across East and Southeast Asia. With China and member states of the Association of Southeast Asia Nations as case studies, multilevel policies in building and financing climate-resilient food systems are further synthesized. The findings confirm significant differences in agriculture-specific emission goals and public financing supports across East and Southeast Asian nations. With an objective to break practical barriers and finance climate-resilient food systems for the future, this paper recommends defining agriculture-specific greenhouse gas emission goals, reorienting the public finance scheme and enhancing mechanisms for the synergy of public and private resources.

● Carbon reduction potential of manure treatment technologies was summarized.

The rapid growth of the livestock and poultry production in China has led to a rise in manure generation, which contributes to the emissions of GHGs (greenhouse gases including CH₄, N₂O and CO₂) and other harmful gases (NH₃, H₂S). Reducing and managing carbon emissions has become a critical global environmental imperative due to the adverse impacts of GHGs. Unlike previous reviews that focused on resource recovery, this work provides an unique insight of transformation from resource-oriented manure treatment to integration of resource recovery with pollution reduction, carbon accounting and trading, focusing on the sustainable development of manure management system. Considering the importance of accounting methodologies for carbon emission and trading system toward carbon neutrality society, suggestions and strategies including attaching high importance to the development of more accuracy accounting methodologies and more practical GHG emission reduction methodologies are given in this paper. This work directs the establishment of carbon reduction methodologies and the formulation of governmental policies for livestock and poultry manure management system in China.

• Intercropping is a useful practice when agricultural sustainability is emphasized.

Intercropping is a traditional farming system that increases crop diversity to strengthen agroecosystem functions while decreasing chemical inputs and minimizing negative environmental effects of crop production. Intercropping is currently considerable interest because of its importance in sustainable agriculture. Here, we synthesize the factors that make intercropping a sustainable means of food production by integrating biodiversity of natural ecosystems and crop diversity. In addition to well-known yield increases, intercropping can also increase yield stability over the long term and increase systemic resistance to plant diseases, pests and other unfavorable factors (e.g. nutrient deficiencies). The efficient use of resources can save mineral fertilizer inputs, reduce environmental pollution risks and greenhouse gas emissions caused by agriculture, thus mitigating global climate change. Intercropping potentially increases above- and below-ground biodiversity of various taxa at field scale, consequently it enhances ecosystem services. Complementarity and selection effects allow a better understanding the mechanisms behind enhanced ecosystem functioning. The development of mechanization is essential for large-scale application of intercropping. Agroecosystem multifunctionality and soil health should be priority topics in future research on intercropping.