Feeding the world's growing population, while producing economic benefits with limited environmental effects, is a major challenge faced by global food supply chains. This is especially apparent when the production stage is predominated by smallholders as they each face varying economic and environmental demands, making it difficult to mobilize them on the ground. This study investigated how the environmental and economic sustainability of wheat supply chains could be improved by analyzing the performance of all stakeholders, especially the smallholders. Results showed that 77% of GHG emissions came from wheat cultivation, and less than 8% of the total economic benefits were recouped during this stage. In contrast, smallholders in the Science and Technology Backyards, reduced their GHG emissions by 16.4% and improved their economic benefits by 1.3- fold. Furthermore, a 2.6-fold increase in profit (1808 USD) with GHG emission reduction was achieved simultaneously by integrating all individual stages as a whole. This study found that the sustainability of the wheat supply chain was mainly affected by wheat cultivation. It also demonstrated the potential efficacy of empowering smallholders and integration of all individual stages as a whole to improve the sustainability of food supply chains.

Producing high economic benefits and high grain yields with limited environmental impacts is crucial for feeding the world's growing population. Yet it remains challenging to improve the performance of one objective without creating unintended consequences for other objectives. This is especially difficult for smallholders navigating a diverse array of environmental and personal demands. This study demonstrates how combining participatory research through the Science and Technology Backyards (STB) approach with Pareto‐based ranking modeling can increase smallholder production while also reducing environmental impact. Through an intensive farmer survey in a 1 × 1 km grid in Quzhou County, we demonstrate that farmers engaged in STBs performed better according to multiple objectives (i.e., optimizing overall grain yield, benefit‐cost ratio, and GHG emissions, without compromising any one of these objectives) than farmer's not engaged in STBs. Moreover, we used a Pareto optimization approach (OPT) to determine the optimal smallholder scenario. We found that under OPT, grain yield could reach 9.5 t/ha, with a benefit‐cost ratio of 2.1, a 100% N recovery efficiency, and 7,395 kg CO₂eq ha⁻¹ GHG emissions. With OPT as a final goal, our research team worked with STB farmers to improve economic and environmental outcomes without compromising yield. Our findings demonstrate that no significant difference was obtained between farmers engaged in STBs and these under OPT. Compared with non‐STB farmers, STB farmers’ grain yield improved by 18%, benefit‐cost ratio improved by 26% due to improved N recovery efficiency, and GHG emissions were reduced by 31%. These improvements demonstrate the power of scientist–farmer engagement for optimizing wheat production. Such engagement allows farmers to modify their agronomic practices to more closely match Pareto optimal conditions, thus improving environmental and economic benefits without compromising yield. Our results provide solid evidence of the potential for sustainable wheat production by combining modeling with participatory research.

Purpose: Smallholders are essential in ensuring food security; however, smallholder-dominated food production often involves high resource-environmental costs. This study analyzed the factors that differentiate horticultural practices, willingness to adopt technology and social networks between optimized practices (OPT) and farmer practices (FP) to provide localized and systematic solutions for the sustainable apple production.Design/methodology/approach: To explore the approach of smallholder-dominated sustainable apple production, 257 apple producers in the Bohai Bay region, a major apple planting area in China, were investigated. Life cycle assessment (LCA), emergy analysis and social network analysis methods were used for evaluation.Findings: The results showed that the net economic profit and emergy sustainability index (ESI) in OPT was 15.8 × 104 RMB·ha-1 and 1.2, respectively, which were 126.9 and 128.0% higher than FP. In contrast, greenhouse gas (GHG) emissions under OPT was 29.3% lower than those under FP. OPT has a higher percentage of adoption of scientific fertilizer application and water-saving irrigation technologies compared to FP. OPT has strong learning abilities, more social resources (such as technical training and sharing technical experience with others) and connections with stakeholders in the apple supply chain. Optimizing smallholders' social capital, willingness to adopt technology, behavioral willingness and technological awareness can promote sustainable apple production.Originality/value: Considering the horticultural practices employed by smallholders in conjunction with their social networks, these factors contributed to the transition of smallholder-led apple production toward sustainability. The findings provided viable options and a theoretical basis for smallholder-dominated crop production to move toward sustainability, with significant implications for policymakers.

Apple production provides smallholders with low economic benefits, while high environmental emissions limit the sustainability of the apple supply chain. Furthermore, coordination to achieve greater economic benefits and environmental protection, thereby improving the sustainability of the apple supply chain, remains underdeveloped. Here, we have analyzed the current status of the economic benefits and environmental emissions of the apple production process and explored the level of collaboration within the apple supply chain, based on an analysis of farmer horticultural practices for high production, high economic benefit, and low environmental emissions, in combination with substance flow analysis. Our study showed that compared with traditional practice, high-yielding, high-efficiency practice allowed fruit yield, partial productivity of nitrogen fertilizer, and economic benefit to increase by 33%, 61% and 49%, respectively, while soil nitrogen residue levels decreased by 13%. The improvement and adoption of technology in the apple-planting process significantly improved the sustainability of the apple supply chain: the economic benefit increased by 63%, while the nitrogen footprint decreased by approximately 68%. Additionally, the application of integrated nutrient management technology in the apple planting process significantly improved the sustainability of apple production, thereby synergistically improving the economic and environmental impact of the apple supply chain.

Space availability and the maintenance of adequate phosphorus (P) supply in the root zone are essential for achieving high yield and P-use efficiency in maize production by manipulating the root morphology and arbuscular mycorrhizal (AM) fungi colonization. A major trade-off exists between root growth and AM colonization that is influenced by soil P supply intensity and space availability. However, how soil P manipulates the root morphological characteristics and AM colonization to compensate for the limitation of root-growth space induced by high-planting density is not clear. Therefore, pot experiments were conducted to investigate interactions between the root growth and AM fungi by optimizing soil P supply to compensate for limited root growth space induced by high-planting density. Similar shoot biomass and P uptake values were obtained in P200 (200 mg P kg⁻¹ soil) under D = 40 (i.e., diameter of the pot is 40 cm) and P400 under D = 30, and similar values were obtained for root length, tap root length, root angle, lateral root density, and AM colonization. However, the improvement in P supply in the root zone, shoot biomass, and P uptake in P400 under D = 20 were lower than in P200 under D = 30, and there were no significant differences in the root parameters between P200 and P400 under D = 20; similarly, the root growth and AM colonization exhibited similar trends. These results suggest that optimizing P supply in the root zone to regulate the interaction between root morphological traits and AM colonization can compensate for limited root-growth space. Although P supply in the root zone increased after the root-growth space was compressed, it could not meet the P demand of maize; thus, to achieve the most efficient use of P under intensive high-density maize production, it is necessary to optimally coordinate root growth space and P supply in the root zone.