Researchers and development organizations regularly grapple with competing ecological and financial strategies for building climate resilience in smallholder agricultural systems, but rarely are such ...approaches considered in tandem. Using a social-ecological simulation model, we explored how different combinations of legume cover cropping, an ecological insurance, and index-based crop insurance, a financial insurance, affect the climate resilience of mixed crop-livestock smallholder farmers over time. The model simulates interactions between soil nutrient dynamics, crop yields, and household wealth, which is carried solely in the form of livestock. We assume legume cover cropping provides biological nitrogen fixation, thereby increasing soil fertility and productivity over time, whereas microinsurance gives payouts in drought years that provide ex-post coping benefits. Our model results indicate that the benefits of cover cropping to mean household income strongly complement the shock-absorbing benefits of microinsurance. Specifically, we found: (1) insurance always provides larger benefits during and in the wake of a drought, while cover cropping progressively reduces poverty in the medium- to long-term; (2) the use of crop insurance solely as an ex-post coping strategy may not reduce the incidence of poverty; and (3) legume cover cropping offers larger relative benefits in more degraded environments and for poor farmers. These results underscore the complementary roles that ecological and financial strategies could play in building resilience in smallholder agricultural systems. The stylized model constitutes an important social-ecological foundation for future empirical research to inform agricultural innovation and sustainable development priorities.
Smallholder agriculture is the foundation of global food systems, yet smallholders face severe socio-economic and environmental challenges that can destabilize livelihoods and threaten their ...resilience. Given that smallholder farmers rely on household production to meet their nutritional needs, management of soil fertility, biodiversity, and other ecological characteristics of agroecosystems directly affects smallholders' capacity to produce sufficient crop nutrients for their diets. However, we lack explicit frameworks linking ecological and nutritional functions of agroecosystems, as well as research exploring farmers' adaptive capacity and agency in mediating these functions, and ultimately, agroecosystem resilience. To address these gaps, we developed an indicator framework to evaluate the complementary roles of ecological and nutritional functions of agroecosystems for smallholder resilience. Paired ecological and nutritional indicators were aggregated into an index representing four agroecosystem functions: (1) Productivity, (2) Diversity, (3) Quality, and (4) Functional Diversity. We then applied this framework and index to a case study of Q'eqchi' Maya smallholders in eastern Guatemala, using farm management and crop quality data from 60 households to determine the status of agroecosystem functions and assess coping and adaptive capacities in response to shocks. More than three-quarters of farms in the sample relied solely on household production of staples to meet their nutritional demands. Across farms, ecological and nutritional indicators were significantly related (Kendall's tau = 0.58, z = 5.7, p < 0.0001), and we found both synergistic (Quality, Functional Diversity) and tradeoff (Productivity) relationships between indicator pairs. We found that farmers using ecological adaptation strategies such as cover cropping and agroforestry had significantly higher levels of agroecosystem functioning and resilience than farmers who were coping with shocks by working off-farm or renting land from plantations. Our findings demonstrate the importance of linking ecological and nutritional functions of agroecosystems through diversified management practices to leverage their synergies. Because smallholder agroecosystems underlie a third of the food system, understanding and promoting their resilience is critical for the social, ecological, and nutritional well-being of global populations.
European agri-food systems must overcome structural lock-ins to achieve more sustainable modes of production and consumption. Yet European regions are highly diverse, and we lack understanding of how ...different regional characteristics may enable or inhibit sustainability transitions. This hinders the development of context-tailored governance strategies. In this paper, we identify and apply sets of spatial indicators to map the regional potentials for agri-food transitions. We first analyse the strength of lock-in to the incumbent agro-industrial paradigm. We then map the enabling environments for two alternative agri-food networks—multifunctional value chains and civic food networks—that each embed distinct social–ecological qualities of agriculture and food. Results demonstrate a large spatial diversity in transition potential, with stronger lock-ins throughout North and Western Europe and stronger enabling environments for agri-food transitions in Italy, France, Switzerland, and Southwest Germany. We find that lock-ins are strongest in livestock-dominated regions and are associated with higher GHG emissions and excess nitrogen levels. Our study demonstrates the need for coordinated public policies that (1) leverage region-specific transition potentials and (2) enable complementary innovations in market-based and community-led networks.
Abstract
Recent analyses indicate that global fruit and vegetable (F&V) production will need to increase by 50%–150% by 2050 in order to achieve sustainable and healthy diets for 10 billion people. ...Although global production of F&V has grown by 50% during the last two decades alone, simply scaling up current systems of F&V production, supply chains, and consumption will inevitably worsen environmental and socioeconomic tradeoffs. This article examines three examples of important F&V—avocados, leafy greens, and tomatoes—to assess the global challenge of meeting dietary recommendations at affordable prices to consumers while sustaining producer livelihoods and minimizing environmental damage. These three cases highlight key characteristics of F&V systems that make the challenge of sustainable expansion especially difficult: knowledge-, input-, and labor-intensive production, high rates of food loss and waste, and low affordability to consumers relative to less nutrient-dense food groups. Our analysis shows that only by investing in innovations that increase diversity, integrate technology, and improve equity will truly sustainable expansion of F&V systems be possible.
The objective of this study was to describe changes in sustainable dietary behaviours (those that support environmental, economic, and physical health) among a sample of US adults during the COVID-19 ...pandemic and to examine differences in changes by individuals’ race/ethnicity and socioeconomic status. Therefore, a cross-sectional online survey study was conducted in April 2021 (N = 1,488, mean age = 42.7 (SD = 12.6)) receiving outpatient care from Michigan Medicine, the University of Michigan health system. Enrolment quotas were established to ensure a diverse sample—one-third of participants identified as African American/Black, one-third Hispanic/Latino, one-third White, and one-third low-income. Participants reported engaging in more behaviours that are supportive of a sustainable diet one year into the COVID-19 pandemic compared to before. This is particularly true regarding ecologically and economically sustaining behaviours such as taking fewer trips to the grocery store, increased use of home grocery delivery, increased cooking at home, and greater consumption of healthy foods. Not all behaviour changes promoted sustainable food systems; namely, the use of farmer’s markets and Community Supported Agriculture (CSAs) declined. White and high-income participants were more likely than African American/Black, Hispanic/Latino, and low-income individuals to engage in ecologically and economically sustainable dietary behaviours during the pandemic. Meanwhile, African American/Black participants reported large increases in physical health sustainable dietary behaviours. To support the continuation of greater engagement with sustainable diets, policies that increase access to public transportation, limit the frequency with which consumers have groceries delivered, increase work-from-home options, and improve access for low-income populations should be prioritised.
Management of crop diversity for improved agroecosystem functioning can provide economic co-benefits to farmers. Yet, there remain critical gaps in understanding how farm management practices evolve ...through agroecological transitions and how agroecological practices affect socioeconomic outcomes such as income and working conditions. We conducted a case study of farms transitioning from conventional tobacco production to diversified agroecological management in a participatory certification network in southern Brazil. We purposively sampled farms along a transition gradient and conducted crop diversity and management surveys and semi-structured, in-depth interviews with household members. Using these data, we assessed indicators of ecological management, income, and working conditions across three transition stages—conventional, transitioning, and agroecological. We found that ecological management indicators increased in magnitude and evenness by transition stage, as transitioning farmers increasingly used practices to support ecological complexity. Agroecological farmers utilized system redesign, a transformative approach to agroecosystem management, rather than efficiency-based or substitution-oriented practices adopted by conventional and transitioning farmers. While farms in transition reported more difficult working conditions and lower incomes, agroecological farmers had similar per capita working hours and improved work quality and occupational safety relative to conventional farmers in the region. On a per capita basis, experienced agroecological farmers earned similar net agricultural incomes and higher net household incomes than conventional farmers, by reducing agricultural expenses and diversifying their markets and livelihoods. Our study is the first to our knowledge to use a transition gradient approach to examine how agroecological transition stage affects both ecological and socioeconomic indicators on farms, providing insights into the processes and pathways by which farmers overcome challenges during transitions. Results highlight the potential for stable profits and improved working conditions on farms following agroecological transitions, within a supportive policy and market context.
The impacts of crop diversity on ecosystem functioning can vary across environmental conditions and land use histories. We conducted a two-year experiment to assess the effects of two diversification ...practices—vetch-oat cover cropping and cucumber-snow pea intercropping—on nitrogen (N) cycling and productivity across a farm management gradient. The field experiment spanned 14 farms in southern Brazil with different long-term management histories, ranging from conventional tobacco to agroecological mixed crop-livestock systems. Along this gradient, farm soils with longer histories of agroecological management had higher soil organic carbon, potentially mineralizable carbon, and extractable phosphorus, captured by a principal component reflecting “biological soil fertility.” We found that benefits of diversification practices for soil N cycling and productivity were ecologically relevant across the farm gradient within the two-year span of our experiment, with the greatest overall performance on agroecological farms. First, vetch-oat cover crops doubled mean N inputs to soil compared to fallows across all farms. Following cover crop incorporation, N mineralization was twice as high on agroecological farms as on transitioning or conventional farms. At vegetable planting, use of cover crop mixtures explained 67% of the variation in soil N availability, after accounting for the effects of background fertility. Finally, vegetable intercrops had higher productivity than monocrops across farms and years (mean LER=1.19), with stronger overyielding in the second year (mean LER=1.27). On a subset of farms, low soil pH constrained the performance of both diversification practices, reducing vetch N2 fixation and vegetable intercrop yield (Land Equivalent Ratio, LER). While prior research has emphasized facilitation between diversified crops in lower fertility soils, our results suggest that diversification's advantages for nutrient cycling and productivity are robust to varied soil conditions and accrue over the course of transitions to agroecological management.
•Functionally diverse crop mixtures enhance nutrient cycling in agroecosystems.•Agroecological management practices build soil fertility on farms.•Cover crops supplied more nitrogen on high fertility, agroecological soils.•Vegetable intercrops overyielded across soil and management gradients.•Acidic soils limited interspecific facilitation by constraining legume nitrogen fixation.
Global industrial agriculture drives worsening environmental and public health crises, prompting a search for transformative agricultural approaches that can maintain productivity while increasing ...social and environmental sustainability. One paradigm gaining traction is agroecology, a science, set of management practices, and social movement. Agroecological management applies ecological knowledge to manage crop diversity on farms (i.e., agroecosystems) and increase multiple functions, including soil nutrient cycling and crop productivity. However, due to the vast heterogeneity of farm management systems and environmental conditions, we lack a mechanistic understanding of transitions to agroecological management, or “agroecological transitions,” and their outcomes. This dissertation develops and applies an interdisciplinary approach to analyze the processes and outcomes of agroecological transitions on family farms in southern Brazil. Chapter 1 provides a conceptual framework for assessing social, ecological, and nutritional functions of agroecosystems across stages of the transition process and introduces the remaining chapters. Chapter 2 focuses on social outcomes of agroecological transitions. I analyzed qualitative and quantitative management and socioeconomic data from 14 farms along an agroecological transition gradient to understand how changing management practices relate to farm income and working conditions. I found that agroecological farms (>5 years certified) achieved income parity and improved working conditions compared to conventional farms in the region. Farms in transition (0-5 years certified), however, struggled to manage ecological processes on their newly diversified farms, which increased work difficulty and reduced profits relative to both agroecological and conventional farms. Chapter 3 examines the cascading relationships between farm management history, background soil fertility, crop diversification practices, and nitrogen cycling during agroecological transitions. I conducted a two-year experiment to test the performance of two legume-based diversification practices, cover cropping and intercropping, across the farm gradient from Chapter 2. Structural equation modeling revealed that after accounting for variation in background fertility across sites, cover crop mixtures explained a further 67% of the variation in soil nitrogen availability at vegetable planting. Consequently, benefits of diversification practices for soil nitrogen cycling were ecologically relevant across farms within the short span of our experiment, with the greatest nitrogen availability overall on agroecological farms. Intercropped cucumber and snow pea had a yield advantage relative to monocrops across the farm gradient, contributing to a mean land equivalent ratio of 1.19 overall, and 1.27 in the second year of the experiment. Chapter 4 evaluates how diversification practices affect two nutritional functions of vegetable agroecosystems. In a factorial field experiment, I studied the individual and combined effects of cover cropping and intercropping on cucumber and snow pea nutrient content and nutrient yield, including protein and six minerals. Total nutrient yield per area increased in the combined diversification treatment, driven by 5.3 times greater cucumber nutrient yield per plant compared to the control. The highest nutrient yield overall was in the cover cropped pea treatment, reflecting 11% higher protein yield per plant compared to the control. These findings provide initial evidence that diversified cropping systems can lead to agronomic biofortification of vegetable crops, particularly in low-input systems. Chapter 5 synthesizes findings from the three studies and proposes an agenda for future research on crop diversification and agroecological transitions. This integrative dissertation illustrates that agroecological transitions, and the crop diversity they employ, offer a pathway toward agriculture that upholds farms’ socioeconomic viability, bolsters key ecosystem functions including soil nutrient cycling, and produces more nutrient-rich crops.
Urban agriculture on green roofs has tremendous potential to enhance food security, economic opportunities, and community building in cities yet faces unique ecological challenges including limited ...soil moisture content for crops. We compared the effects of two green roof soil moisture management practices, sedum (Sedum album) groundcover versus watering, on performance and quality of three perennial culinary herbs: thyme, mint, and oregano. Individually and interactively, sedum groundcover and watering significantly impacted parameters of performance (biomass, vitality, and module coverage) and quality (total phenolic concentrations) of the three culinary herbs during early stages of establishment while having variable impacts during later developmental stages. Our results suggest that sedum groundcover can serve as a substitute for watering of hardy culinary herbs on green roofs on the basis of plant performance and quality. Findings can be applied to inform agroecological water management of herbs and other hardy specialty crops on green roofs toward enhancing their drought tolerance and advancing sustainable urban agriculture.
Farming systems that support locally diverse agricultural production and high levels of biodiversity are in rapid decline, despite evidence of their benefits for climate, environmental health, and ...food security. Yet, agricultural policies, financial incentives, and market concentration increasingly constrain the viability of diversified farming systems. Here, we present a conceptual framework to identify novel processes that promote the emergence and sustainability of diversified farming systems, using three real-world examples where farming communities have found pathways to diversification despite major structural constraints. By applying our framework to analyze these bright spots in the United States, Brazil, and Malawi, we identify two distinct pathways—network and institutional—to diversification. These pathways emerge through alignment of factors related to social and ecological structure (policies, institutions, and environmental conditions) and agency (values, collective action, and management decisions). We find that, when network and institutional pathways operate in tandem, the potential to scale up diversification across farms and landscapes increases substantially.
Diversified farming systems that support environmental health and food security are increasingly constrained by agricultural policies, financial incentives, and market concentration. We present a conceptual framework to identify novel processes that promote diversified farming systems, which we apply to analyze bright spots in the United States, Brazil, and Malawi. Blesh et al. identify two distinct pathways—network and institutional—enabling agricultural diversification and find that, when these pathways operate in tandem, the potential to scale up diversification across farms and landscapes increases substantially.
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