Agronomy for Sustainable Development最新文献

In the context of ever-growing demand for food and associated concerns regarding the environmental impacts of high-input agricultural systems, there is growing interest in mixed farm enterprises to deliver greater sustainability compared with mono-enterprise production systems. However, assessments of such systems are complex and require high-resolution data to determine the true value and interconnectivity across enterprises. Given the scarcity of information on mixed crop–livestock systems and the difficulties of its analysis, we perform life cycle assessment using temporally high-resolution data (2019–2022) from a long-term experiment in South America to evaluate the ‘cradle-to-farmgate exit’ greenhouse gas emissions intensities of four rotational crop–livestock systems. Systems evaluated were continuous cropping: 2 years of continuous cropping; short rotation: 2-year continuous cropping plus 2-year pasture; long rotation: 2-year continuous cropping followed by 4-year pasture; and forage rotation: continuous pasture. Emissions intensities for beef throughput were reported as kilograms of carbon dioxide equivalents (CO₂-eq) per kilogram of liveweight gain (LWG) using the Intergovernmental Panel for Climate Change’s Sixth Assessment Report (AR6 2021) CO₂ characterisation factors. Point estimate results were found to be 11.3, 11.8, 11.8 and 16.4 kg CO₂-eq/kg/LWG for continuous cropping, short rotation, long rotation and forage rotation, respectively. Emission averages arising from crops, which were separated from animal-based emissions using economic allocation, were 1.23, 0.53 and 0.52 kg CO₂-eq/kg for soybean, wheat and oat, respectively. The inclusion of soil organic carbon stock changes had notable effects on reducing each system’s emissions: by 22.4%, 19.2%, 25.3% and 42.1% under continuous cropping, short rotation, long rotation and forage rotation, respectively, when soil organic carbon was included. Given there are few life cycle assessment studies available on such mixed-enterprise ‘semi-circular’ systems, particularly with novel primary data, this study adds critical knowledge to agri-food-related sustainability literature by addressing environmental issues in complex production systems compared to extant and broad coverage of mono-enterprise systems.

The intercropping of winter oilseed rape with frost-sensitive service plants can provide a diversity of services including weed control and N supply for oilseed rape. This practice started to be adopted by farmers and has therefore become one of the most popular intercropping in Western Europe. However, in Switzerland, such intercropping leads to contrasting yields. The growth of service plants and the benefits they provide have also been found to be variable. The factors explaining these variabilities remain unclear. Our study aimed to better understand this variability under a temperate climate thanks to the regional agronomic diagnosis framework. In this study, we first investigated the main factors explaining this variability and then aimed to rank them to identify ways to better manage such intercropping systems. A network of 28 farmers’ fields planted with winter oilseed rape intercropped with service plant mixtures was studied. Farmers’ practices were diverse in terms of specific composition of the service plant mixture, pest management, and fertilization. We observed that the growth of oilseed rape and service plants in fall was highly variable. We determined that in late fall, the main drivers of the service plant mixture dry weight were specific composition of the mixture and precipitation. The introduction of buckwheat in the service plant mixture enhanced its late fall biomass. The oilseed rape grain yields ranged from 0.4 to 5.0 t ha⁻¹ and were lower than that of the local reference in 75% of the fields. This was mainly explained by insect pest damage in spring due to a very limited use of insecticide in our field network combined with a lack of alternative pest management strategies. This work provides further elements to investigate the causes leading to the high variability we observed, together with the local observations that will benefit the farmers.

Determinants of farmer well-being can be derived from objective and subjective measures of social components, environmental sustainability indicators, and quality of life indices, as well as the multiple scales that farms and farmers operate. Yet, despite multiple frameworks on farmer well-being, the extent to which farmer-expressed values are used in the development of farmer well-being indicators is unclear. Challenges can arise from extracting indicators that are insufficiently grounded in place, or that inadequately incorporate context and biocultural relations and practices. Here in this scoping review, we synthesize the methodologies in the literature on assessing farmer well-being and identify the extent to which farmer well-being domains are derived from values expressed directly by farmers. We consolidated and coded 92 papers to respond to the following questions: (1) What are the most frequent farmer well-being domains in published studies? (2) What methods are used to elicit multidimensional farmer well-being domains? (3) Do well-being domains used in the literature adequately reflect a biocultural context, including place-based influences on well-being? Our results show that economics and social relationships are frequent domains of how farmer well-being is identified and assessed. These domains tend to be measured simultaneously, while less common domains, such as governance and place, are rather isolated. A suite of methods was used to assess well-being domains, ranging from basic surveys to in-depth participant observation. Yet, we identify gaps in the methods for deriving farmer well-being indicators. Specifically, methods that refer to farmer-expressed values were rare and domains identified through a place-based approach were often not recorded, but, arguably, critical in developing multidimensionality of farmer well-being. We show that while the translocal approach is well represented in established well-being frameworks, farmer expression is not foundational in well-being assessments but is needed in order to center farmer values when generating indicators of well-being.

Effects of climate change and especially the associated climate variability require farmers to adjust to increasing frequencies of extreme events. In the agriculturally highly productive Romanian Plain, the frequency, intensity, and duration of heatwaves and drought have increased over the past 20 years. Although recent surveys revealed farmers’ awareness of climate change and enumerated a number of farm adaptation measures in the Romanian context, a systems approach to adaptation that allows conclusions on farm vulnerability and adaptive capacity is missing. Here, we use archetypal analysis to elucidate and characterize for the first time the types of adaptation responses of arable farmers in southern Romania. We conducted semi-structured interviews with 30 farmers managing 51,500 ha located across the southern lowlands of Romania, selected for their diversity of management approaches. Farmers were asked about experienced climatic disturbances, crop production losses during the most extreme events over the past 5–10 years, and the adaptation measures they implemented over that period of time. In addition, structural characteristics of the farm were recorded. The adaptation measures were classified and mapped on the efficiency, substitution, and redesign gradient used to classify sustainability stages. Results revealed three archetypes of adaptation, consisting of measures at field and farm level ranging from predominantly efficiency-enhancing ones (e.g., crop choice and management and risk insurance) to complete farm redesign involving agrotechnical and financial management changes. Structural farm characteristics did not explain differences between farms in their association with one of the archetypes. Our approach and results show for the first time both the need for strengthening farmer-level support in one of Europe’s key food production areas and the lessons that can be drawn from the outlier adaptation examples. Current European and national policies offer opportunities for farmer organizations in Romania to make these conclusions actionable.

Legume-grass mixtures are often used to increase forage yield and soil fertility in managed grasslands, but it remains unclear whether these benefits could be further improved by utilizing optimal legume-grass seeding ratios and phosphorus (P) fertilization. Here, we conducted a 5-year field experiment across 3 sites to investigate the effects of legume-grass seeding ratio and P fertilization on forage yield and soil quality. This experiment included mixtures comprised of two legume species and two grass species at five legume-grass ratios (3:7, 4:6, 5:5, 6:4, and 7:3), and monoculture of each species. P fertilizer was applied at the rate of 0, 9, 18, or 27 kg P ha^-1 year^-1. Plant diversity effects, e.g., complementarity and selection effects, were assessed by comparing yield of mixtures with monocultures. Our results show that a legume-grass mixture with a seeding ratio of 3:7 under moderate P fertilization resulted in the highest forage yield among all monocultures and mixtures, for each of the three sites, with persistent and consistent transgressive overyielding. Notably, greater soil organic matter, total nitrogen, enzymatic activity, and microbial biomass were observed with the legume-grass ratio of 3:7, compared to monocultures or other seeding ratios. Structural equation modeling indicated that the legume-grass ratio of 3:7 achieved highest yield through directly improving complementarity effect, and indirectly promoting selection effects because of increased fungal biomass. P fertilization directly enhanced soil nutrient and enzymatic activities, and further improved complementarity effect, resulting in high forage yield and soil quality. These results indicate that forage diversification practices with low legume-grass seeding ratios and moderate P fertilization can simultaneously benefit forage production and soil quality in managed grasslands. Overall, our study suggests that low legume seeding proportion in legume-grass mixtures combined with moderate nutrient management is a useful strategy for sustainable and highly productive managed grasslands.

Modern “intensive” agriculture drives the biodiversity-climate crisis but is also central to global food security. Future farming needs management approaches that maintain (or even enhance) food production while reducing negative climate and biodiversity impacts. Intercrops could provide part of the solution, increasing biodiversity and boosting production with fewer inputs. However, barriers remain to their wide-scale uptake, in particular tailoring intercrops to local equipment, management practice, and environment. We analyze data from multiple trials of cereal-legume intercrops conducted on farms across Europe between 2018 and 2021. Our study is the first attempt, to our knowledge, to quantify the yield benefits of cereal-legume intercropping undertaken at commercially relevant scales for farms across Europe. We used crop performance ratio (CPR)—the ratio of the observed intercrop yield compared to the expected yield based on monoculture yields—as our metric of intercrop performance. Using CPR, we found a roughly 30% yield gain across all sites. However, CPR was modulated by a number of factors. CPR was not strongly affected by management except for the negative effects of direct drilling and the positive effects of organic fertilizer addition. CPR also depended on intercrop composition (number and identity of components), background yields (being highest where yields were lower), and rainfall (being higher with higher rainfall). Our findings allow us to reduce uncertainty about how intercrops will perform in realistic local farm conditions, give guidance for tailoring intercrops to local farming conditions, and provide key goals for further work to integrate intercrops into sustainable farming systems.

This study aimed to evaluate the stability of cacao clone production by analyzing the dynamics of pod production over time. It investigates correlations in multi-year production levels and explores how genetics influence both intra-annual and inter-annual temporal production dynamics of total and healthy pods. To address these questions, data were analysed from a clonal cacao trial conducted over a period of 18 years in Costa Rica. Longitudinal data analysis provided a clearer understanding of the link between yields over successive years. The best-fit model proved to be the ante-dependence model. This model indicated that the correlation between two successive years was relatively stable, and the correlation between years decreased as the interval between years increased. These correlations are also higher as the age of the trees increases. The clones differ more in terms of their production of healthy pods than total pod production. Four dynamic patterns, considering both intra- and inter-annual production, were identified, revealing differences in production timing and distinct peaks for each class. Inter-annual variability analysis revealed differences in healthy pod production among classes, with some displaying more sustainable production dynamics over 18 years. Intra-annual variability analysis showed significant variation in production periods among clones, with different production distributions throughout the year allowing selection of escape and or resistant clones. The study emphasized the importance of genetics in sustainable cacao production, with potential implications for clonal selection. It was suggested to combine clones of different classes to mitigate risks and spread harvests, emphasizing that resilience is a crucial criterion in cacao breeding programs to effectively meet new challenges. Further research is recommended to explore the influence of various environmental factors and facilitate more efficient selection in perennial crops, with the aim of selecting more resilient clones, a particularly important objective in the context of climate change.

Rice–crayfish farming systems (RCs), a novel rice cropping system, have gained rapid popularity in many countries due to their economic advantages. Fertilizers tend to be applied in large quantities for higher profits, but has high burden on resources and environment, especially in terms of the carbon emissions. It is crucial to explore an optimal fertilization strategy with high productivity and low carbon emissions for the sustainable development of RCs. However, information about C emissions is incomplete, regarding the indirect C emissions during the rice growing season as well as C emissions during the crayfish culture period. We conducted field experiments to investigate the effects of five fertilization strategies including no fertilization (CK), farmer’s practices (FP), optimized fertilization (OPT), organic fertilization only (OF), and organic fertilizer substitution (OPTOF) on the productivity, economic benefits, greenhouse gas (GHG) emissions, carbon footprint, and sustainability index of RCs. Results showed that OPT reduced direct (by 6.7%) and indirect (by 37.0%) GHG emissions during the rice growing season while maintaining rice (95%) and crayfish (104%) yields compared with that of FP. Additionally, the soil organic carbon storage and annual economic benefit of the OPT increased by 20.1% and 4.7%, respectively, whereas the carbon footprints of unit area, unit grain yield, unit energy yield, and unit of economic output decreased by 29.5%, 27.2%, 24.5%, and 32.7%, compared to the FP, respectively. The sustainability index (0.78) of the OPT treatment was significantly higher than that of other treatments due to its higher productivity and lower the carbon footprint. In conclusion, optimal fertilization strategy in RCs could achieve to increase productivity while reducing carbon footprint. This is conducive to the sustainability of RCs. Future attention in RCs should be focused on the development and promotion of such strategies.

Sustainable food production for a growing world population will pose a central challenge in the coming decades. Organic farming is among the feasible approaches to achieving this goal if the yield gap to conventional farming can be decreased. However, uncertainties exist to which extend—and for which phenotypes in particular—organic and conventional agro-ecosystems require differentiated breeding strategies. To answer this question, a heterogeneous spring barley population was established between a wild barley and an elite cultivar to examine this question. This initial population was divided into two sets and sown one in organic and the other in conventional managed agro-ecosystems, without any artificial selection for two decades. A fraction of seeds harvested each year was sown the following year. Various generations, up to the 23th were whole-genome pool-sequenced to identify adaptation patterns towards ecosystem and climate conditions in the allele frequency shifts. Additionally, a meta-data analysis was conducted to link genomic regions’ increased fitness to agronomically related traits. This long-term experiment highlights for the first time that allele frequency pattern difference between the conventional and organic populations grew with subsequent generations. Further, the organic-adapted population showed a higher genetic heterogeneity. The data indicate that adaptations towards new environments happen in few generations. Drastic interannual changes in climate are manifested in significant allele frequency changes. Particular wild form alleles were positively selected in both environments. Clustering these revealed an increased fitness associated with biotic stress resistance, yield physiology, and yield components in both systems. Additionally, the introduced wild alleles showed increased fitness related to root morphology, developmental processes, and abiotic stress responses in the organic agro-ecosystem. Concluding the genetic analysis, we demonstrate that breeding of organically adapted varieties should be conducted in an organically managed agro-ecosystem, focusing on root-related traits, to close the yield gap towards conventional farming.