Agronomy for Sustainable Development最新文献

In temperate Europe, agroforestry practice is gaining interest due to its potential to enhance carbon (C) sequestration and mitigate greenhouse gas (GHG) emissions in agriculture. To date, the effects of agroforestry on the spatial and temporal dynamics of soil carbon dioxide (CO₂) and methane (CH₄) fluxes are still poorly quantified. Here we present a systematic comparison of soil CO₂ and CH₄ fluxes between agroforestry and monoculture cropland systems for the first time, based on two-year field measurements at three sites on different soils in Germany. Each site had an adjacent alley cropping agroforestry system and monoculture, and the agroforestry was established on former monoculture croplands 1 to 11 years prior to this study. We found that area-weighted soil CO₂ emissions from agroforestry (3.5−8.1 Mg C ha⁻¹ yr⁻¹) were comparable to monocultures (3.4−9.8 Mg C ha⁻¹ yr⁻¹), whereas area-weighted agroforestry generally had higher soil CH₄ uptake (0.4−1.3 kg C ha⁻¹ yr⁻¹) compared to monocultures (0.1−1.2 kg C ha⁻¹ yr⁻¹). Seasonal variations of soil CO₂ and CH₄ fluxes were strongly regulated by soil temperature and moisture, and the spatial variations were influenced by soil texture. Our results suggest that conversion of monoculture cropland to long-term alley cropping agroforestry system could be considered as a sustainable agriculture practice for its great potential for mitigating CH₄ emissions.

Anthropogenic disturbances have led to substantial declines in grassland legumes worldwide, with consequences for plant nutritional quality, biodiversity, food-web complexity, and ecosystem sustainability. Despite the growing acknowledgment of the significance of legume presence, it has rarely been investigated how the introduction of legumes affects the growth of neighboring plants over time and the underlying mechanisms that influence biomass production during grassland utilization. To address these gaps, we established legume-restored grasslands followed by 7 years of mowing (once a year) and phosphorus (P) application to simulate defoliation management and improve legume performance. We observed significant higher compensatory growth rate and aboveground biomass in legume-restored grasslands compared to naturally restored grasslands. These improvements can be attributed to the combined effect of an increase in legume proportion in plant communities and the improved performance of neighboring plant species after legume restoration (nursing effect). This nursing effect further increased the relative importance of the mass ratio effect in explaining the improved biomass in legume-restored grasslands after mowing. Moreover, the compensatory growth rate in naturally restored grasslands decreased significantly over time, while the compensatory growth rate in legume-restored grasslands tended to increase, indicating higher sustainable biomass production in legume-restored grasslands. P application increased aboveground biomass, but did not alter plant community structure, regardless of whether legumes were used to restore grasslands. Here, we show for the first time that legume introduction can sustainably provide higher biomass production through enhancing compensatory growth in natural grasslands that have suffered from prolonged or intense defoliation. This highlights the critical role of leguminous species in a long-term grassland restoration.

The perennial grain intermediate wheatgrass (Thinopyrum intermedium, commercial name Kernza^TM) has been proposed as a diversification crop for producing forage and grain and providing ecosystem services to farmers. Although a few studies have addressed farmers’ interests in the crop, information is lacking about the links between farmers’ goals and crop management, i.e., how farmers aim at integrating this crop in their systems. Closing this gap, this paper analyzes for the first time the introduction of intermediate wheatgrass (IWG) from a farmer perspective, as a set of decision plans and goals. The overarching orientations of the farm and organization of the production system, referred as strategic decisions, interact with short-term crop management (i.e., tactical decisions) and farmers’ goals for IWG. In total, 17 individual semi-structured interviews and 2 collective crop management prototyping workshops in France were used to analyze farmers’ rationales as a function of their farm systems, agronomic constraints, and know-how. The study demonstrates that farmers’ interests in IWG revolved around multiple ecosystem services and financial returns. Three ideal-types of farms testing IWG emerged from the relationships between existing farming systems and goals for IWG. The strategic and tactical decisions regarding the integration and management of IWG were contingent on the farming systems, the goals for IWG, the farmers’ know-how, and their ability to mitigate risks. Implications for the future development of intermediate wheatgrass as a niche innovation are considered based on farmers’ points of view. This study provides insights into the ideas and concerns of French farmers regarding IWG and proposes a framework for discussing the introduction of a new crop in a farm system.

Far removed from the agricultural fire “hotspots” of Northwestern India, rice residue burning is on the rise in Eastern India with implications for regional air quality and agricultural sustainability. The underlying drivers contributing to the increase in burning have been linked to the adoption of mechanized (combine) harvesting but, in general, are inadequately understood. We hypothesize that the adoption of burning as a management practice results from a set of socio-technical interactions rather than emerging from a single factor. Using a mixed methods approach, a household survey (n = 475) provided quantitative insights into landscape and farm-scale drivers of burning and was complemented by an in-depth qualitative survey (n = 36) to characterize decision processes and to verify causal inferences derived from the broader survey. For communities where the combine harvester is present, our results show that rice residue burning is not inevitable. The decision to burn appears to emerge from a cascading sequence of events, starting with the following: (1) decreasing household labor, leading to (2) decreasing household livestock holdings, resulting in (3) reduced demands for residue fodder, incentivizing (4) adoption of labor-efficient combine harvesting and subsequent burning of loose residues that are both difficult to collect and of lower feeding value than manually harvested straw. Local demand for crop residues for livestock feeding plays a central role mediating transitions to burning. Consequently, policy response options that only consider the role of the combine harvester are likely to be ineffective. Innovative strategies such as the creation of decentralized commercial models for dairy value chains may bolster local residue demand by addressing household-scale labor bottlenecks to maintaining livestock. Secondary issues, such as timely rice planting, merit consideration as part of holistic responses to “bend” agricultural burning trajectories in Eastern India towards more sustainable practices.

Rice (Oryza sativa L.) is extensively cultivated in South Asia mostly under puddled transplanted conditions which are highly energy and water-intensive with low income and degraded soil properties. Off-late, alternative crop establishment practices such as direct seeded rice, system of rice intensification, and zero-till rice have gained importance as viable options for resilient farming. However, the valuation of these different rice systems in terms of ecosystem services is not systematically carried out. The research objective was to evaluate the ecosystem services of different rice establishment systems to determine their potential and importance as ecological assets and strive to find out the most productive establishment method while minimizing its effects on the natural resources, environment, and human health. A novel valuation approach was developed using an experimental and bottom-up method to assess the value of rice systems based on three aspects: provisioning, regulation and maintenance, and cultural services. To evaluate the ecosystem services of different rice establishment methods, 11 indicators were selected. The seven rice establishment methods evaluated were random-puddled transplanted rice, line- puddled transplanted rice, conventional till-machine transplanted rice, zero till-machine transplanted rice, system of rice intensification, conventional till, and zero till- direct seeded rice. The results revealed that the value of rice ecosystem services across establishment practices averaged US$ 9092 ha^-1 yr^-1. Direct seeded rice (zero till/conventional till) provided the highest ecosystem services at US$ 9491 ha^-1year^-1 and random puddled transplanted rice was lowest at US$ 8767 ha^-1 year^-1. Provisioning, regulation-maintenance, and cultural ecosystem services contributed 20.3,79.4, and 0.3% to the total ecosystem services value. The research emphasizes the favorable environmental attributes of direct seeded rice, which may be integrated into the policy framework for better decision making to guarantee the sustainability of the agri-food system in the mid-Indo-Gangetic regions.

Over the past 15 years, Argentina has experienced a consistent stagnation in rice grain yield, diverging from the substantial annual increases observed in other South American countries. It is important to understand the causes of this stagnation to take corrective measures to increase the productivity and competitiveness of Argentine rice farmers. This research incorporates data from ten growing seasons to explore rice yield improvements through enhanced management practices. Our study aims to determine the yield potential and yield gap and to identify key factors associated with yield losses in irrigated rice fields in Argentina. Yield and management practice data from farmers were collected via a survey that included 2470 site-year observations (2010–2020). The yield potential was simulated using the Oryza model. The yield gap was calculated as the difference between the yield potential and the average yield from the field. Our findings indicated that 22% of the current yield gap is due to the sowing date, 9% is associated with the adoption of rotation/succession, and 5% is associated with the early onset of irrigation up to the V3 stage. The implementation of these practices has demonstrated the potential to reduce the current yield gap from 48% to 33%. Additionally, previous work has shown that the amounts of N and K fertilizers influence the yield gap. Rice yield stagnation is limited by both low genetic progress and farmers’ reluctance to adopt improved management practices. Hence, a 10-day shift toward early sowing in Argentina (high yield versus low yield) would result in a 510 kg ha⁻¹ yield increase. Addressing these management issues illustrates the power of this approach for impact assessment to support policy and investment prioritization and for monitoring the impact of research and extension programs.

Research has shown that soil-borne beneficial microorganisms can enhance plant growth, productivity, and resistance against pests and pathogens and could thus serve as a sustainable alternative to agrochemicals. To date, however, the effect of soil-beneficial microbes under commercial crop production has been little assessed. We here investigated the effect of root inoculation with nine well-characterized bacterial and fungal strains and two consortia on tomato performance under intensive tomato crop management practices. We measured the impact of these root inoculations on plant growth, fruit quality, yield, and pest and pathogen incidence. While most microbial strains showed weak effects, we found that the fungal strains Trichoderma afroharzianum T22 and Funneliformis mosseae significantly increased marketable tomato yield. Moreover, we found that inoculation with most of the fungal strains led to a significant reduction in the incidence of the devastating leaf-mining pest Tuta absoluta, while this effect was not observed for bacterial inoculants. In addition, we found that microbial inoculations did not impact the incidence of introduced natural pest enemies, supporting their compatibility with well-established integrated pest management strategies in horticulture. In summary, the observed general positive effects of soil microbes on tomato yield and resistance reinforce the move toward broader adoption of microbial inoculants in future crop production, ultimately improving agricultural sustainability.

Urban agriculture is often associated with sustainable agricultural practices. However, the variety of systems qualifying as urban agriculture and the limited information available about their sustainability question this direct relationship. To better understand differences in intra-urban agriculture systems and their sustainability, this paper proposed an holistic classification of urban agricultural systems and collected knowledge about the environmental, social, and economic sustainability of these systems. Such a classification is important to evaluate sustainability claims on urban agricultural systems, anticipate potential sustainability trade-offs between urban agricultural systems and propose preventive measures to address these, and ultimately guide the sustainable deployment of these systems. Compared with existing classifications, the novel classification scheme proposed here accounts for technological, social and economic characteristics of urban agriculture systems to better distinguish between all systems. It was built on 91 scientific papers. The economic intensity of production was, for example, an important characteristic to coherently group urban agriculture systems. The intensity of cooperation between all actors was another characteristic emphasized for certain urban agriculture systems. One end of the classification scheme describes ground-based open, socially motivated urban agriculture systems with high cooperation intensity and low production intensity. The other end of the classification scheme describes building-integrated quasi-closed systems with high production intensity. In between, we find: building-integrated conditioned systems, ground-based conditioned systems, and building-integrated open systems. Mapping sustainability claims from literature in the classification scheme supported its definition along the three characteristics. For example, urban farming was associated with job creation, food safety, water savings, and higher yields while urban gardening with educational potentials, biodiversity improvements, and lower yields. Their display in the classification scheme was therefore supported. To further support the use of the proposed scheme, additional quantitative research to better understand and quantify the sustainability of urban agriculture systems is required.

Against the backdrop of global warming, the agricultural sector grapples with the dual challenge of safeguarding food security while fulfilling carbon neutrality. Currently, although nitrogen fertilizer and mulch use to enhance maize yields is well-documented, systematic evaluations are lacking in the carbon neutrality potential and holistic benefits, including greenhouse gas (GHG) implications, associated with these strategies. Here, using the calibrated DeNitrification-DeComposition (DNDC) model, we conducted a long-term simulation (1980−2019) incorporating various scenarios of nitrogen fertilizer (N₁: conventional nitrogen fertilizer; N_0.7: 70% conventional nitrogen fertilizer) and mulch (CK: no-mulch; PM: plastic film mulch; SM: straw mulch), resulting in a baseline scenario (CKN₁) and five mitigation scenarios (CKN_0.7, PMN₁, PMN_0.7, SMN₁, SMN_0.7). We revealed an average net global warming potential during the maize growing season of 5293 kg CO₂ eq ha⁻¹, with the most GHG derived from N₂O (53%). Considering GHG costs, the net environmental and economic benefits in maize amounted to 5089 CNY ha⁻¹. Presently, Hainan, Henan, Liaoning, and Jilin provinces exhibit a state of low net global warming potential and high net environmental and economic benefits in maize cultivation. Of the mitigation scenarios, only SMN₁ concurrently reduced GHG emissions (− 59%) and amplified net environmental and economic benefits (+ 21%) in China. Our results, which provide the first calculation of the combined benefits of mulch and nitrogen fertilizer including GHG costs, not only underscore the immense potential of mulch for enabling carbon neutrality, but also offer valuable insights for policymakers and industry in selecting suitable mulch techniques for agricultural production.

Within hilly agricultural landscapes, topography induces lateral transfers of runoff water, so-called interplot hydrological connectivity. Runoff water from upstream plots can infiltrate downstream plots, thus influencing the water content in the root zone that drives crop functioning. The impact of runoff on crop functioning can be crucial for optimizing agricultural landscape management strategies. However, to our knowledge, no study has specifically focused on the impact on crop yield. The current study aims to comprehensively investigate the impact of runoff on crop functioning in the context of Mediterranean rainfed annual crops. To quantify this impact, we conduct a numerical experiment using the AquaCrop model and consider two hydrologically connected plots. The experiment explores a range of upstream and downstream agro-pedo-climatic conditions: crop type, soil texture and depth, climate forcing, and the area of the upstream plot. The experiment relies on data collected over the last 25 years in OMERE, an environment research observatory in northeastern Tunisia, and data from literature. A key finding in the results is that water supply through hydrological connectivity can enhance annual crop production under semiarid and subhumid climate conditions. Specifically, the results show that the downstream infiltration of upstream runoff has a positive impact on crop functioning in a moderate number of situations, ranging from 16% (wheat) to 33% (faba bean) as the average across above ground biomass and yield. Positive impact is mostly found for higher soil available water capacity and under semiarid and dry subhumid climate conditions, with a significant impact of rainfall intra-annual distribution in relation to crop phenology. These research needs to be expanded by considering both a wider range of crops and future climate conditions.