Agronomy for Sustainable Development最新文献

In certain Sub-Saharan African countries, a transition is underway that involves increased motorization and herbicide use. This study is the first to investigate whether these recent changes are transforming the way legumes (cowpeas, groundnuts, and Bambara beans) are grown by men and women across a range of farm types. Reducing this knowledge gap is crucial to ensure that legumes remain a sustainable lever for agroecological intensification in evolving farming systems. In Benin and Burkina Faso, 261 households were interviewed regarding their farming systems. A hierarchical clustering was used to identify farm types with contrasting constraints. Ten farm types were identified, ranging from a very small, highly constrained sorghum farm in Central-North Burkina (2.5 ha, no motorization) to a large maize-soybean farm owning tractors (62 ha). Our findings indicate that compared to home-consumed cereals (sorghum and maize) and cash crops (cotton and soybean), no farm prioritized traditional legumes at the farm level. While the most constrained farms in North Burkina Faso already dedicated 25–30% of their land to pure legume crops and frequently practiced legume-sorghum intercropping (61% of farms), an opposite trend was observed in West Burkina Faso and in Benin, where some constraints have been lifted with motorization. The use of motorization on the main crops and farm expansion has led farmers there to also intensify traditional legume cropping systems by using herbicides, simplifying crop rotations and avoiding intercropping. In all study sites, traditional legumes continue to be more highly valued by women than by men. This study identifies research perspectives tied to the dual challenge of implementing agroecological intensification with legumes in West Africa: small-scale subsistence farmers need financial and technical support due to land constraints, while larger, labor-constrained farms require mechanization and improved land access for women.

Ecosystem functionality and essential services for human well-being have been degraded by intensively managed monoculture cropping systems. Intercropping may offer a means of maintaining and increasing agricultural soil multifunctionality without reducing productivity. However, whether the maintained or enhanced soil multifunctionality by intercropping is related to the potential function changes of soil microbiome driven by intercropping is poorly understood, limiting the optimization of these systems for sustainable intensification. Therefore, we investigated crop yields and soil multifunctionality in a long-term field experiment established in 2009. The study evaluated soil physical structure stability, carbon (C), nitrogen (N), and phosphorus (P) cycling, abiotic stress regulation and related functional genes under intercropping systems (chickpea/maize, faba bean/maize, oilseed rape/maize, and soybean/maize) and monocultures of the component crops at three P fertilizer application rates (0, 40, and 80 kg P ha^-1). Intercropping significantly increased crop grain yields and soil multifunctionality by 27.3 and 34.6%, respectively, compared with the weighted mean values of monocultures, irrespective of phosphorus application rate. It also significantly increased the relative abundance of genes related to C-, N-, and P-cycling functions by 15.2%, 10.8%, and 26.3%, and the relative abundance of genes was related to weighted mean diameter of aggregates, soil compaction, total nitrogen, soil microbial biomass carbon, soil respiration, soil nitrate reductase, β-cellobiohydrolase and leucine aminopeptidase. There were synergies between soil C and N cycling and between physical structure stability and C or N cycling, and trade-offs were observed between physical structure stability and phosphorus cycling. The positive effect of intercropping on soil multifunctionality was associated with enhanced enzyme activities and other soil properties and consequently increased crop yields. The results highlight the important role of intercropping in sustaining soil function and elucidate the mechanisms involved, offering novel insights into its role in reducing dependence on non-renewable P resources in agricultural ecosystems.

The adoption of crop-livestock mixed farming systems offers product diversification and reduces reliance on external inputs compared to traditional cropping systems. However, the impact of rotation design on the production benefits of mixed farming under climate change remains unclear. This study used the well-validated APSIM model to assess the performance of mixed farming systems across historical and future climate scenarios. We established six reference crop rotations, including wheat, canola, field pea, oats, and barley, and introduced six crop-lucerne rotations with sheep grazing to represent the mixed farming systems. Across the Riverina Plain, soil nitrogen accumulation during the pasture phase in the mixed system was 66.3 kg ha⁻¹ year⁻¹ during the historical period, increased to 80.4–94.4 kg ha⁻¹ year⁻¹ under future climates. Nitrogen accumulation contributed to a crop yield advantage over pure-crop systems, with historical increases of 28.1%, 23.0%, 54.8%, and 8.9% for wheat, barley, oats, and canola, respectively. Under future climates, the yield advantage of the first wheat crop after lucerne was constrained, while other crop sequences exhibited enhanced yield benefits. Ley biomass and sheep production were closely related to rainfall availability. In middle and eastern Riverina, mixed systems showed a significant gross margin advantage over pure-crop systems during the historical period; however, it exhibited 0–250 AUD ha⁻¹ year⁻¹ lower in the drier western areas, except in cases where oats were included in the rotation. The economic disadvantage in dry areas would gradually diminish in the future. The mixed system with wheat-canola-wheat-canola showed the highest gross margin across all climate scenarios, while the wheat-field pea-wheat-oats sequence exhibited the greatest gross margin improvement compared to the pure-cropping system. This is a pioneering study on the performance of crop-livestock mixed systems under climate change, offering implications for farming system improvement in the study area and similar regions.

Pesticide use in agriculture has significant negative impacts on human health, ecosystems, and natural resources. The failure to meet targets for pesticide reduction at the farm level underscores the need for a systemic, holistic approach that considers the diversity of actors and the complexity of the farming systems involved. The landscape level provides a relevant framework for addressing the reduction of pesticide use and impacts. In this study, we analyzed 19 initiatives aimed to reduce pesticide use or its impacts in agriculture in a Mediterranean peri-urban plain in southern France. Drawing on insights from landscape agronomy and research on collective action, we developed a novel conceptual framework to capture and analyze the diversity and complementarity of local dynamics of pesticide reduction. Through interviews, workshops, and farm surveys, we examined the factors driving the emergence of these initiatives and assessed their anticipated impacts on farming practices, landscape patterns, and natural resources at the landscape level. The results revealed that these initiatives were led by diverse, and sometimes conflicting, strategies to reduce pesticide use that focused mainly on optimizing pesticide use in dominant agricultural systems, alongside farm reconfiguration and biodiversity integration strategies. This study advances current knowledge by providing actionable insights to improve collective action at the landscape level, such as spaces for synergies for landscape-level coordination and identified barriers to this coordination. Our findings emphasize the importance of embracing complexity when designing and implementing pesticide-reduction strategies.

Crop residues and their management are central to the performance of cropping systems. However, we lack information on the extent to which crop residues influence their N₂O emissions, especially over the long term. This knowledge is key as it determines if benefits from crop residue management such as increased carbon storage or soil and water preservation should be weighed against potential stimulation of N₂O emissions. To lessen this gap, we investigated the effect of crop residue quantity (dry matter yield ranging from 0.29 to 11 t·ha⁻¹) and quality (C:N ranging from 8 to 157) on N₂O emissions and compared it to the effects of other key drivers related to environmental conditions and management practices, such as soil moisture, temperature, and fertilization. We relied on a 12-year dataset of N₂O emissions from an arable cropping experiment in northern France and implemented an original approach combining definition of “restitution cycles” and use of both linear regression and machine learning algorithms to predict N₂O emissions at that scale. This allowed to assess the contribution of the various drivers of these emissions, among which crop residue and their management. Our results show that the main drivers of cumulative N₂O emissions were the amount of mineral nitrogen fertilizer and restitution cycle length. Crop residue characteristics had a relatively minor effect. Among the residue quality indicators, only crop residue C:N ratio affected N₂O emissions. Tillage, temperature, and water-filled pore space had no detectable or systematic impact. These findings, which are original in terms of the cropping system scale considered, suggest that crop-residue management is not likely to significantly affect N₂O emissions from arable cropping systems in northern France. They open up opportunities for agricultural decision-making without concern for increased N₂O emissions as an unwanted trade-off.

Adoption of cover crops in corn-producing regions of the United States (U.S.) has progressed at an uneven pace. Since corn is a nitrogen (N) demanding crop, a limited understanding of N fertilizer management for corn following cover crops is among the major barriers to widespread adoption of cover crops. To address this critical knowledge gap, we conducted the first meta-analysis to systematically examine the impacts of N fertilization on corn yield and N content following cover crops, considering various agronomic practices and soil conditions. Studies comparing corn production with and without cover crops were selected for analysis, with 392 and 228 individual observations included for corn yield and N content, respectively. Results depicted that the integration of cover crops tends to boost corn yield and N content by 11% and 22%, respectively. The type of cover crop species impacts corn performance, with legumes improving yield by more than 50% in the subsequent non-fertilized corn. Grass and brassica cover crops require nearly 200 kg N ha⁻¹ to achieve yield comparable to fallow systems, due to N immobilization by cover crop residues. The timing of cover crop termination also plays a critical role in yield outcomes, with late termination (within 1 week of corn planting) producing higher corn yields than early termination. Additionally, manure and ammonium-based fertilizers perform better than urea-based fertilizers in systems involving cover crops. Key considerations include the selection of cover crop species and N fertilizer types to maximize the agronomic, environmental, and economic benefits. These findings suggest that a well-managed corn cropping system has the potential to effectively integrate cover crops while achieving yield goals.

As the degradation of agricultural soils and loss of biodiversity are becoming more widespread in response to intensive agricultural practices, the strategic management of vineyards for resilient and balanced production is of utmost relevance. The choice and intensity (e.g., frequency, depth, and/or stocking rate) of vineyard floor management practices determine how soil, water, and weed management are carried out, directly influencing vineyard soil functionality and biodiversity. Grower motivations and challenges in adopting specific practices remain poorly understood, especially across diverse landscapes with varying environments and production goals. This study aimed to explore differences in vineyard floor management across Australia, where soil and water conservation, along with weed and biodiversity management, are key production concerns. An online survey collected information from 199 growers across Australia, who were divided into three comparative groups based on their under-vine management practices: Cultural (no herbicide use), Herbicide, and Hybrid (combination of herbicides and tillage). Vineyard floor management intensity ratings were assigned to each grower based on the types and frequencies of practices they indicated. The Cultural group consisted of growers managing vineyards that were 83% smaller in size, had 32% lower management intensity ratings, used fewer inputs, and were more strongly motivated by goals of improving soil health and enhancing terroir expression compared to the other two groups. For the Herbicide and Hybrid groups, grapevine yield was a stronger motivation, while suppressing weeds was one of the main challenges reported. This indicates that alternatives to the widespread practice of using herbicides are of primary interest. In addition, for the first time, this study emphasized that vineyard floor management intensity rating was a significant driver in growers’ perceptions of sustainability and biodiversity, as those with lower intensity management perceived higher sustainability parameters. We therefore suggest that the future structuring of research and extension services should focus on reducing the intensity of vineyard floor management practices across Australia.

The growth and urbanization of the world’s population necessitate re-evaluating how cities procure food. Urban food systems rely on industrialized agriculture and extended supply chains which generate significant environmental impacts. Controlled-environment agriculture within cities is argued to improve urban food system sustainability and resilience by shortening supply chains and producing food efficiently indoors. However, its performance across diverse regions and energy grid mixes remains unclear, given variability in carbon intensity and sourcing strategies throughout the year. This limits the ability to generalize findings and optimize urban controlled-environment systems for environmental benefits. To address this gap, this study examines the environmental impacts of controlled-environment lettuce farming in Canadian cities. Results show that this farming provides environmental benefits, such as reduced (or comparable) water and land use relative to conventional agriculture. Climate change impacts, however, vary from 0.8 to 25 times those of conventional lettuce due to high energy demands. In carbon-intensive grids, such as Alberta, emissions per kilogram of lettuce exceed those of conventional agriculture. In contrast, provinces with low-carbon energy grids, like Quebec, have climate change impacts that are comparable to market-average lettuce or much lower than Canadian greenhouses. This study highlights the interplay between environmental performance, energy sources, and geography, offering insight into where and under what conditions controlled-environment agriculture can be low-carbon. Because of the high energy intensity of controlled-environment production in cold climates, deployment should be prioritized in cities with low-carbon grids or developed alongside nearby renewable sources to realize its potential to supply local produce and contribute to low-carbon urban food systems.

To address sustainability challenges in the North-Western Indo-Gangetic Plains (NW-IGP), conservation agriculture and diversification from rice to maize have been promoted. However, nitrogen (N) management under conservation agriculture remains largely similar to conventional practices, resulting in limited improvements in nitrogen-use efficiency (NUE) and often yielding results comparable to conventional tillage. This study explores alternative N management strategies for conservation agriculture that sustain maize yields, improve soil quality, reduce N losses, and increase net returns. A 40-year simulation using the DSSAT-CERES-Maize model was conducted to evaluate long-term impacts. The field experiment compared surface residue-retained zero tillage and residue-incorporated conventional tillage with three beneath-the-surface-placed (point/band) N application rates (100, 125, and 150 kg ha⁻¹) and respective controls (0 kg N ha⁻¹), alongside a no-residue farmers' practice with surface-broadcasted 150 kg N ha⁻¹. The model effectively captured the dynamics of key growth and harvest parameters, including phenology, biomass, and was applied to assess the long-term sustainability of these practices. Results revealed that zero tillage (5416 kg ha⁻¹) outperformed conventional tillage and farmers' practice, with 6.6% and 28% higher grain yields over 40 years and demonstrated greater resilience during drought and high-rainfall years. Zero tillage with 125 kg N yielded nearly the same as 150 kg, indicating N input can be reduced by 25 kg ha⁻¹ (~17%) without yield loss. After 40 years, soil organic carbon in the top 20 cm increased to 0.77% in zero tillage, compared to 0.59% in conventional tillage and 0.43% in farmers’ practice. Economically, 125 kg N ha⁻¹ under zero tillage yielded returns comparable to 150 kg N ha⁻¹ under current and reduced fertilizer subsidy conditions, and outperformed under no-subsidy conditions. Thus, reducing the recommended N dose from 150 to 125 kg ha⁻¹ under zero tillage sustained maize yields and returns while enhancing soil carbon and NUE in the NW-IGP.

The development of agroecology requires an ambitious, multi-level transformation of knowledge and innovation systems. The literature shows that intermediary actors and organizations play an important role in this transformation. In our article, we introduce the idea that agricultural research experiment stations can be considered as innovation intermediaries to foster agroecological transitions. Previous studies have shown how agricultural experiments are transformed by their inclusion in a multi-actor process, but they do not adequately explain how they contribute to the transition of agri-food systems. Our analysis focuses on nine case studies of on-station system experiments by France’s National Research Institute for Agriculture, Food and Environment. These on-station system experiments have the specificity to be managed by researchers interacting with non-academic stakeholders from their local areas. We have called these Open on-Station System Experiments. We documented them over five years, during which we collected information and data through observation, participation, eliciting activity, and cross-case analysis. We show how OSEs fulfil five knowledge and innovation intermediation functions that contribute, in practice, to the transition of agri-food systems: problem solving; production of transition visions through the design and experimentation of breakthrough agroecological innovations; production of operational and scientific knowledge responding to different users’ requirements; by generating operational and scientific knowledge based on Findable, Accessible, Interoperable, Reusable data; participation in networking between stakeholders and interactional learning about transition using experiments as boundary objects. Based on these findings, we show for the first time the conditions under which agricultural research experiment stations can fulfill the functions of innovation intermediaries and thus contribute to fostering agroecological transitions.