Agroecology: Principles and Practices for Diverse, Resilient, and Productive Farming Systems

The potential for wildflower interventions to enhance natural enemies and pollinators in commercial apple orchards is limited by other management practices

Soil microbial communities under cacao agroforestry and cover crop systems in Peru

Climate change is having an impact on European agriculture and will increasingly do so in the future. Agroforestry, the integration of trees or shrubs in agricultural production systems, has been repeatedly voiced as a productive, sustainable and resilient approach of food production. Quantifying agricultural benefits of agroforestry in the context of resilience to current and future climate change in Europe is challenging. In an online survey we gathered 60 experts’ assessment on the resilience of different forms of agroforestry (silvoarable, silvopastoral and systems with hedgerows, riparian buffer strips and windbreaks) in diverse European regions to various climate change variables. Across all regions and independently of the agroforestry system type, agroforestry systems were observed to show stable yields until now (0% change of yield compared to -8% in non-agroforestry systems). Experts expected yield differences between agroforestry and non-agroforestry to increase in future with − 20% yield until 2050 in non-agroforestry systems, while they expected agroforestry systems to accommodate the changes (0% yield change). This gap was highest in central and eastern Europe. In north-western and northern Europe, small yield increases were expected in agroforestry systems. Silvopastoral, silvoarable and systems with hedgerows, riparian buffer strips and windbreaks were similar in terms of observations/expectations of changes in yield. The quality of saleable agricultural products until 2050 was estimated to show a distinct difference between non-agroforestry and agroforestry systems. In particular in arable and hedgeless systems where all of the surveyed experts expected quality to be reduced, while only 48% and 55% thought so for silvoarable and hedgerow systems, respectively. Heavy precipitation events, prolonged drought, late frost, summer heat waves and hail were the main threats by climate change listed by experts. Our expert study emphasizes a general resilience of agroforestry systems to climate change impacts, regardless of the exact system type and climate region.

Cover crops, as either a living plant or mulch, can suppress weeds by reducing weed germination, emergence and growth, either through direct competition for resources, allelopathy, or by providing a physical barrier to emergence. Farmers implementing conservation agriculture, organic farming, or agroecological principles are increasingly adopting cover crops as part of their farming strategy. However, cover crop adoption remains limited by poor and/or unstable establishment in dry conditions, the weediness of cover crop volunteers as subsequent cash crops, and seed costs. This study is the first to review the scientific literature on seed traits of cover crops to identify the key biotic and abiotic factors influencing germination and early establishment (density, biomass, cover). Knowledge about seed traits would be helpful in choosing suitable cover crop species and/or mixtures adapted to specific environments. Such information is crucial to improve cover crops’ establishment and growth and the provision of ecosystem services, while allowing farmers to save seeds and therefore money. We discuss how to improve cover crop establishment by seed priming and coating, and appropriate seed sowing patterns and depth. Here, three cover crop families, namely, Poaceae, Brassicaceae, and Fabaceae, were examined in terms of seed traits and response to environmental conditions. The review showed that seed traits related to germination are crucial as they affect the germination timing and establishment of the cover crop, and consequently soil coverage uniformity, factors that directly relate to their suppressive effect on weeds. Poaceae and Brassicaceae exhibit a higher germination percentage than Fabaceae under water deficit conditions. The seed dormancy of some Fabaceae species/cultivars limits their agricultural use as cover crops because the domestication of some wild ecotypes is not complete. Understanding the genetic and environmental regulation of seed dormancy is necessary. The appropriate selection of cover crop cultivars is crucial to improve cover crop establishment and provide multiple ecosystem services, including weed suppression, particularly in a climate change context.

Lemongrass (Cymbopogon nardus) as cover crop was suitable planted with agroforestry and monoculture system on post-coal mining revegetation land. The study investigated the influence of planting system, varieties, and plant spacing against the lemongrass growth on post-coal mining land under the agroforestry and monoculture system. Two lemongrass varieties were planted under on both planting systems. The growth variables of lemongrass measured were the tillers number per clump, leaf length, and canopy width. The results showed that the planting system and lemongrass varieties were able to increase the growth of lemongrass. Plant spacing treatment was able to increase the tillers number per clump. The agroforestry system was able to increase leaf length and canopy width of lemongrass. However, monoculture system was able to increase the tillers number per clump. The G2 variety had better growth on all measured variables either in agroforestry and monoculture system compared to Sitrona 2 Agribun variety. The plant spacing of 0.5 m × 0.5 m had greater tillers number per clump of lemongrass compared to plant spacing of 1 m × 1 m.

Farmers’ management of functional biodiversity goes beyond pest management in organic European apple orchards

1 School of Environmental and Forest Sciences, College of Environment, University of Washington, Seattle, Washington, USA. 2 School of Social Work, Indigenous Wellness Research Institute, University of Washington, Seattle, Washington, USA. *Correspondence to: Jessica Hernandez, School of Environmental and Forest Sciences, College of Environment, University of Washington, Anderson Hall, Box 352100, Seattle, WA 98195 USA. E-mail: jhernan@uw.edu. Michael Spencer, School of Social Work, University of Washington, Box 354900, Seattle, WA 98105 USA. E-mail: mspenc@uw.edu. KEY WORDS: indigenous science, indigenizing, ecology. Human Biology, Winter 2020, v. 92, no. 1. doi: 10.13110/humanbiology.92.1.05. Copyright © 2020 Wayne State University Press, Detroit, Michigan 48201 introduction Weaving Indigenous Science into Ecological Sciences: Culturally Grounding Our Indigenous Scholarship Jessica Hernandez1 * and Michael S. Spencer2 * Indigenous peoples are the original stewards of their native and ancestral lands, having maintained the balances of their ecosystems since time immemorial. However, as a result of colonization, imperialism, and the mass genocide of Indigenous peoples, environmental systems have been drastically changed. Since Western ideologies such as capitalism and Western science were introduced, Indigenous stewards and their knowledge systems have been invalidated and often ignored in environmental and ecological discourse. Their complex nature-culture nexus has been dismissed and suppressed, and European men have been given the credit for their discoveries and nuances in environmental and ecological discourse(Wildcat2009).Forinstance,JamesCook is considered the pioneer of oceanography and navigation, and Giffford Pinchot is considered the father of forestry. However, oral Indigenous history recounts how Indigenous people navigated the oceans before colonialism (e.g., Polynesians) and served as stewards of their forests (e.g., Amazonian tribes) (Anderson 2009; Walker 2012). Despite having generations of knowledge formation based on fijirst-hand observations, Indigenous peoples have been left out of these conversations and discourses. In this special issue of Human Biology, titled “Indigenous Science and Ecology,” we weave together fijive articles that demonstrate the nuances of Indigenous scholarship in the ecological and environmental sciences. These articles uplift Indigenous ancestral knowledge that has led these authors to contribute Indigenous perspectives within their respective fijields. This special issue highlights how Indigenous peoples can indeed lead us to more holistic and efffective ecological andenvironmentalsolutionsinachangingclimate. Given the drastic changes we continue to face as a result of climate change, it is imperative now more thanevertoliftupIndigenousvoices,perspectives, and knowledge systems. Climate change impacts Indigenous peoples’ culture-nature nexus, furtheringtheinjusticestheyface (Maldonadoetal.2014). These injustices come from centuries of oppression , violence, and desecration they have endured under postcolonialism. Despite the genocide and forced assimilation tactics used in the past, and which continue to be used today, against Indigenouspeoples ,theirteachingshavebeenpreserved in their communities through oral traditions and cultural practices (Lauer 2012). Their resiliency demonstrates how Indigenous peoples can be the focal point of any effforts to adapt to and mitigate climate change. Including Indigenous voices in climate change narratives and discourse can lead to holistic solutions, as our fijive articles contend. 000 ■ Hernandez and Spencer While some of their teachings were in relation to their living conditions in the past, Indigenous cultures offfer knowledge systems that can adapt to new climates, spaces, times, and environment, as demonstrated by the contributors to this special issue. These adaptations are seen through the eyes of Indigenous peoples who are also forcefully displaced as a result of climate change, ongoing militarization, and other results of settler colonialism (Laidlaw et al. 2015). This furthers our conclusion that Indigenous peoples’ teachings can serveassolutionstotheenvironmentalcrisisweare currently facing in a changing climate, due to their resilienceandadaptivecapacity(Aftandilian2011). Our special issue demonstrates how Indigenous science can help heal our Mother Earth, and our fijive peer-reviewed articles do an outstanding job of displaying this through their authors’ current research, analysis, and critical lens. These fijive articlesweaveIndigenousscienceintoenvironmental and ecological discourse, amplifying Indigenous perspectives, voices, and ways of knowing. It is important to note that Indigenous science cannot be defijined by one sole defijinition, because it consists of all Indigenous knowledge systems— local, regional, and global.While some Indigenous knowledges share similarities with others, they differ based on the geographic location of each tribe, nation, or community. This is because Indigenous knowledgesystemsareplacebasedandnotsocially acquiredthroughWesternsystems(e.g.education) (Singer...

Modeling the coupling processes of evapotranspiration and soil water balance in agroforestry systems

Cover cropping and chemical fertilizer seasonally mediate microbial carbon and phosphorus metabolisms in an apple orchard: Evidence from the enzymatic stoichiometry method

This study examined the last four decades of the existing academic literature related to the environmental impacts of using cover crops in agricultural production systems. Data were collected from the Web of Science database, resulting in a sample of 3246 peer-reviewed articles published between 1980 and 2021. We combined two advanced scientometrics analysis software (i.e., CiteSpace 6.0.R1 and Gephi 0.9.2) to identify the trajectory of the literature, hotspots, and frontiers. We developed authorship-, institution-and country-levels networks to examine academic cooperation over the last forty years. Our findings revealed that the number of peer-reviewed outputs documenting the environmental effects of cover crops has consistently increased, with a notable rise in publications between 2015 and 2021. Eighteen salient research topics were identified in the literature, including winter cover crops’ effects on soil health, cover crops’ effects on nitrous oxide emissions, and the relationship between cover crops and nitrate leaching. Based on the citation-clustering analysis, the trajectory of the literature may be divided into three stages. Studies in Stage 1_A (1980–2000) mainly assessed the role of cover crops in nitrogen management. In Stage 1_B (2001–2010), the research evaluated the impact of using different cover crop mixtures on farming systems. In Stage 2 (2011–2021), studies primarily addressed the environmental impacts of cover crops, particularly their effects on physical and chemical soil properties. Finally, the countries with the most outputs were the United States, Brazil, and Spain. The U.S. Department of Agriculture-Agricultural Research Service was the main contributor to the literature on the environmental impacts of cover crops.

Purpose: Indigenous knowledge Systems is a discipline that has received acknowledgement even from United Nations forums. However, the discussion of Indigenous Knowledge Systems practiced in the Dande valley of Zimbabwe is still hazy and unclear and the concerned citizens like academics ,call for an institutional and policy change has been ignored. Though there has been a ministry of Science and technology in Zimbabwe, its focus was mainly on modern science, even though indigenous knowledge was mentioned ,evidence on the ground shows that indigenous knowledge was given very little consideration. It is also the thrust of this paper to point into perspective the adaptive measures taken by the Dande community against climate change using Indigenous Knowledge Systems (IKS). Issues discussed focused on the role of IKS on plant phenology, health and risk reduction, food and security, art natural resource management as they are understood in the Climate change discourse. Research Design: The study was conducted in the Dande Valley of Zimbabwe which consists of 3 districts of Mashonaland Central Province namely; Mbire, Mount Darwin and Muzarabani. Data for this study were solicited through structured interviews, interviews with indigenous experts, traditional leaders, members of the Dande community; focus group discussion was also used to manipulate the community perception, current practices on adaption to climate change. Information on IKS and climate change was gathered through the participatory approach. The strength in this approach lies in the fact that it involves documenting of real events, recording what people say and observing behaviour.` Findings: Results from the study revealed that many scholars and some academics have a negative attitude towards IKS; however information gathered proved that IKS plays an important role in the Dande community. IKS adaptive strategies against climate change are based on environmental issues like, plant phenology, health and health, and natural resources management. The study established that there is every reason for policy change and implementation in Zimbabwe . To ensure sustainability of the IKS ,the study suggests that institutes of higher learning like Bindura University of Science Education and the Zimbabwe Open University to devise supportive systems that enable collection, analysis, storage information and dissemination of IKS information through a Meta Data base focusing on Dande Valley and other parts of the country rich in indigenous knowledge. Originality/Value: This study will add to the knowledge base of IKS and climate change in fragile environments and of particular note the Dande Valley in Zimbabwe. The study will also enlighten and provide information to policy makers, researchers, academics and general citizens to make informed decisions. It will also help all interested stakeholders to think seriously on IKS and climate change discourse.

In global terms, European farms produce high yields of safe and high quality food but this depends on the use of many off-farm inputs and the associated greenhouse gas emissions, loss of soil nutrients and other negative environmental impacts incur substantial societal costs. Farmers in the European Union receive support through a Common Agricultural Policy (CAP) that comprises direct payments to farmers (Pillar I) and payments related to rural development measures (Pillar II). This paper examines the ways in which agroforestry can support European agriculture and rural development drawing on the conclusions of 23 papers presented in this Special Issue of Agroforestry Systems which have been produced during a 4-year research project called AGFORWARD. The project had the goal of promoting agroforestry in Europe and focused on four types of agroforestry: (1) existing systems of high nature and cultural value, and agroforestry for (2) high value tree, (3) arable, and (4) livestock systems. The project has advanced our understanding of the extent of agroforestry in Europe and of farmers’ perceptions of agroforestry, including the reasons for adoption or non-adoption. A participatory approach was used with over 40 stakeholder groups across Europe to test selected agroforestry innovations through field trials and experiments. Innovations included improved grazing management in agroforestry systems of high nature and cultural value and the introduction of nitrogen fixing plants in high value timber plantations and olive groves. Other innovations included shelter benefits for arable crops, and disease-control, nutrient-retention, and food diversification benefits from integrating trees in livestock enterprises. Biophysical and economic models have also been developed to predict the effect of different agroforestry designs on crop and tree production, and on carbon sequestration, nutrient loss and ecosystems services in general. These models help us to quantify the potential environmental benefits of agroforestry, relative to agriculture without trees. In view of the substantial area of European agroforestry and its wider societal and environmental benefits, the final policy papers in this Special Issue argue that agroforestry should play a more significant role in future versions of the CAP than it does at present.

Development of the soil macrofauna community under silvopastoral and agrosilvicultural systems in Amazonia

The grand challenge of increasing production and access to nutritious and safe food to meet growing populations under threat to climate change and climate variability requires systems and transdisciplinary approaches towards agri-food systems. Sustainable agricultural intensification (SAI) focuses on increasing agricultural production from existing farmland without any adverse environmental impacts. There are three major components of SAI which include: (i) genetic intensification (e.g., focused on improving yields, resistance to pests and diseases, tolerance to abiotic stresses, increasing nutritional quality of food products, and using precision breeding, genetics, and genomics tools); (ii) ecological intensification (e.g., focused increasing diversification, farming, cropping and agroforestry systems, resource use efficiency, integrated water, nutrient and pest management); and (iii) socio-economic intensification (e.g., focused on markets, value addition, income generation, policy, creating enabling environment, and building social capital). Climate-smart agricultural (CSA) practices emphasize greenhouse gas emissions, water footprint, and focus on both adaptation and mitigation strategies. Few selected SAI and CSA practices include minimum and no-tillage; cover crops; crop diversity and genotypes selection for effective water use and stress tolerance; diversification (crop mixtures and rotations; perennials, agroforestry systems; forage crops; dual purpose crops); and nutrient recycling from livestock. Overall, developing adoption and scaling of these practices will require convergence of biophysical and social sciences, participatory approaches, public and private sector engagement and commitment of resources from all donor agencies for research and development, human and institutional capacity building.

* Preface to the Second Edition * Acknowledgments * Introduction * Chapter 1. The Ecological Role of Biodiversity in Agriculture * Traditional Agroecosystems As Models of Biodiverse Farms * The Ecological Role of Biodiversity * The Nature of Biodiversity in Agroecosystems * Chapter 2. Agroecology and Pest Management * The Nature of Agricultural Habitats and its Relation to Pest Buildup * Crop Diversification and Biological Control * Chapter 3. Plant Diversity and Insect Stability in Agroecosystems * Ecological Theory * Theory Dilemmas * Chapter 4. Insect Manipulation Through Weed Management * Weeds As Sources of Insect Pests in Agroecosystems * The Role of Weeds in the Ecology of Natural Enemies * Insect Dynamics in Weed-Diversified Crop Systems * Isolating the Ecological Effects of Weed Diversity * Crop-Weed Management Considerations * Chapter 5. Insect Management in Multiple-Cropping Systems * Patterns of Insect Abundance in Polycultures * Herbivore Trends in Polycultures * Case Study 1: Maize Intercrops and Pest Attack * Case Study 2: Cassava Intercrops and Pest Incidence * Case Study 3: Reducing Stemborers in Africa * Living Mulches: A Special Type of Intercrop * Methodologies to Study Insect Dynamics in Polycultures * Management Considerations * Chapter 6. Insect Ecology in Orchards Under Cover-Crop Management * Selecting and Managing Cover Crops in Orchards * Case Study 1: Apple Orchards in California * Case Study 2: Pecan Orchards in Georgia * Case Study 3: Summer Cover Crops in Vineyards * Chapter 7. The Influence of Adjacent Habitats on Insect Populations in Crop Fields * Crop Edges and Insect Pests * Field Boundaries and Natural Enemies * Designing and Managing Borders * Case Study 1: Exchange of Arthropods at the Interface of Apple Orchards and Adjacent Woodlands * Manipulating Crop-Field Border Vegetation * Case Study 2: Biological Corridors in Vineyards * Case Study 3: Strip Management to Augment Predators * Chapter 8. The Dynamics of Insect Pests in Agroforestry Systems * The Effects of Trees in Agroforestry on Insect Pests * Designing Natural Successional Analog Agroforestry Systems * The Need for Further Research * Chapter 9. Designing Pest-Stable Vegetationally Diverse Agroecosystems * Monocultures and the Failure of Conventional Pest-Control Approaches * Towards Sustainable Agriculture * Requirements of Sustainable Agroecosystems * Designing Healthy Agroecosystems * Healthy Soils--Healthy Plants * Restoring Diversity in Agricultural Systems * Enhancing Surrounding Biodiversity * Case Study 1: Diversification of an Onion Agroecosystem in Michigan * Case Study 2: A Diversified Small Farming System in Chile * Conclusion * References * Index