Agro-ecological service crops (ASC) can increase the vegetation complexity of agroecosystems leading to a positive impact on natural enemies of arthropod pests and on weed control. In this study, two ASC terminations (green manure and roller crimper) and a Mater-Bi-mulched control (MB) were compared in order to describe the effects on pests and beneficial dynamics in an organic vegetable system. The trials were conducted over two consecutive growing seasons in 2014 and 2015. Zucchini were grown as cash crop and barley as ASC. Pests and natural enemies were monitored fortnightly by visual samplings along the whole zucchini-growing season. Zucchini plants showed a faster vegetative growth in MB treatment than in ASC terminations. In both years, MB plots were characterized by higher soil temperature and higher leaf nitrogen concentration resulting in plants more susceptible to Aphis gossypii infestations. In all the experimental plots, natural enemies controlled aphid infestations and no insecticide and sprays were necessary. In conclusion, the tested ASC techniques have been suggested as a tool to mitigate aphid infestation.

Cattle manure value chains play important biological and economic roles in smallholder crop–livestock systems in developing countries, but relative to other livestock products our understanding of the nature and impact of manure sales is limited. In regions with an active manure trade, farmers face a choice between manure use on-farm and sales, which affects nutrient flows and participant incomes. We analyzed the manure value chain operating in south-central Vietnam as an example of the function and role of manure trade in crop–livestock systems. Lowland cattle farmers sell manure through a network of chain participants, including small-scale collectors, lowland and highland traders, to pepper, coffee, dragon fruit and rubber farms in the central highlands and southeast coast. We collected and summarized quantitative data (e.g., manure-related labor, manure transactions, and fertilizer and manure use) gathered in semi-structured interviews with value-chain participants [lowland cattle owners (n = 101), traders (n = 27) and end users (n = 72)]. Lowland cattle owners were selected by stratified random sampling, and subsequent participants were identified in preceding interviews. One key finding concerns the seasonality of the manure value chain: most manure flowed between February and August (lowland dry season and period of peak highland demand) from lowland communes to highland coffee and pepper farms for use as organic soil amendments. Fewer sales occurred, at a lower price, to southeast coastal dragon fruit farms and rubber companies. Value addition to manure occurred via drying, bagging, collection, transport and composting. The presence of local traders facilitated market sales for smallholder cattle owners, and prices through the value chain generally reflected costs for value addition. The geographic distribution of cattle relative to agricultural land influenced the flow of manure, with net outflows from regions with higher animal density to regions with lower density and higher value crop production. Manure trade was an important source of supplementary income for farmers and a primary livelihood activity for traders. Value chain participant net incomes ranged from near US$100 yr−1 for lowland farmers to over US$13,000 yr−1 for traders, and returns to labor were just over US$0.50 h−1 for lowland farmers and US$2 h−1 for traders. The quantitative information generated during our descriptive assessment provides an important first step toward manure value chain improvement, indicates survey methods that can be applied in other areas, and identifies next steps necessary to evaluate chain evolution and resilience.

In this article, I consider how local oral history narratives provide smallholder farmers with both material and symbolic resources in adapting to climate change. I draw from the case study of an agrarian village in Madagascar that was struck by a destructive category 3 cyclone. In the weeks following the storm, oral history knowledge occupied an increasingly visible role within the community, as younger farmers interacted with elders to hear tales of past storms. Through these shared accounts, people discussed specific techniques on how to cope with environmental uncertainty. They also created a sense of shared history, which provided individuals across generations an entry point into the local historical record. Overall, the process of sharing oral history accounts can contribute to community resilience, with resiliency encompassing not only technical or ecological factors, but also the more affective realms of shared legacies, hope and belonging.

Exotic crops—plant species grown in relatively small quantities and not traditionally cultivated in a country or region—are often intimately linked with the ethnic origins of their maintainers and are a principal source of culinary and nutritional diversity for many people. Recognizing that a wealth of exotic crop diversity and associated knowledge is held by small-scale growers in the UK, Garden Organic initiated the Sowing New Seeds project to capture and preserve some of this valuable resource by building a seed collection and knowledge base. To establish a sample of this diversity and knowledge, we undertook a survey at 31 allotment sites in the Midlands region of the UK with the objectives of identifying the exotic crops cultivated, characterizing the demography of those who grow them, understanding their direct use values, and assessing their potential indirect use value for the diversification and improvement of other crops. Results reveal that 26% of the food crops recorded are exotic and that they are grown by people belonging to 13 different ethnic groups. The majority save their own seed, indicating that these crops are performing well in the UK, with grower selection providing the basis for their continuing success. Further, most maintainers swap seed with other growers, indicating that exotic crops are likely to be gradually diversifying in response to different growing conditions—a positive sign for their value for local food security and as national genetic resources with potential for use in crop improvement programs. The research highlights the multitude of benefits that growers obtain through cultivating exotic crops, which are not only related to nutrition and culinary requirements, but also to general health and well-being, culture, and a range of other forms of life enrichment. It is critical that growers are encouraged and supported in continuing to cultivate, save and pass on their exotic crops to younger generations, as well as to protect allotments from development in order to maintain this important diversity adapted to local growing conditions. Importantly, many exotic crops currently grown on a small scale may enter into commerce, and thus expand the diversity of the UK's food crop base. Such a shift may be particularly important in the face of the increasingly detrimental impacts of climate change on crop production. We conclude that exotic crop diversity could be more important for future nutrition, health and food security than we currently appreciate.

This paper provides a brief discussion on the implications and outcomes of ethnographic filmmaking as a means to understanding environmental perception among farming communities. I argue that the unique contribution of filmmaking as a research method lies in its epistemological ability to engage with diverse ways of knowing. In this paper, I provide a close examination of a vignette filmed during my research to demonstrate how this methodological and analytical approach can be used to reveal environmental perception and knowledge as processes, rather than as substances.

By potentially disrupting crop production, climate change has been implicated as a threat to global food security. We focus on two elements of climate change: elevated atmospheric carbon dioxide concentration, or e[CO2], and reduced water availability, as caused by drought. Both variables have been shown to have effects on crop physiology, although there is considerable evidence of interactions and moderation by species-specific differences. Measuring traits helps scale environmental effects up to functional responses, and we focused on traits connected to photosynthesis, which has a close association with crop yield. We measured the response of four physiological traits—quantum photosynthetic yield, chlorophyll content, root:shoot ratio and leaf area—across a diverse set of seven annual crop species grown under three levels of e[CO2] (450, 575 and 700 ppm) and two levels of water availability (minimum ~45 and ~15% VWC) in a growth chamber. Species included barley, durum wheat, maize, oats, sorghum, pinto bean and sunflower. Our regression analysis focused on testing for interactions between e[CO2] and water limitation and determining relative effect sizes of climate change impacts across species, data that can be used for species-specific modeling or determining appropriate levels of environmental variables in free-air CO2 enrichment studies designed to extend small-scale experimental results to the field. Across all species and all traits, the strongest effect of e[CO2] occurred from 450 to 575 ppm, with only marginal differences from 575 to 700 ppm. We found substantial declines in leaf area across all species as a result of e[CO2] and wide variability in leaf area responses to water limitation. Other traits showed weak and variable responses to both e[CO2] and water limitation. While our data confirm that elements of global change, especially increased atmospheric CO2 concentration, do affect traits related to photosynthesis, we found no discernible pattern to suggest which crops might be more resistant to e[CO2].

The potential to improve soils to help farmers and ranchers adapt to and mitigate climate change has generated significant enthusiasm. Within this discussion, grasslands have surfaced as being particularly important, due to their geographic range, their capacity to store substantial quantities of carbon relative to cultivated croplands and their potential role in mitigating droughts and floods. However, leveraging grasslands for climate change mitigation and adaptation will require a better understanding of how farmers and ranchers who rely on them for their livelihoods can improve management and related outcomes. To investigate opportunities for such improvements, we conducted a meta-analysis of field experiments that investigated how soil water infiltration rates are affected by a range of management options: adding complexity to grazing patterns, reducing stocking rates or extended rest from grazing. Further, to explore the relationships between observed changes in soil water infiltration and soil carbon, we identified papers that reported data on both metrics. We found that in 81.9% of all cases, responses of infiltration rates to identified management treatments (response ratios) were above zero, with infiltration rates increasing by 59.3 ± 7.3%. Mean response ratios from unique management categories were not significantly different, although the effect of extended rest (67.9 ± 8.5%, n = 140 from 31 experiments) was slightly higher than from reducing stocking rates (42.0 ± 10.8%; n = 63 from 17 experiments) or adding complexity (34.0 ± 14.1%, n = 17 from 11 experiments). We did not find a significant effect of several other variables, including treatment duration, mean annual precipitation or soil texture; however, analysis of aridity indices suggested that grazing management may have a slightly larger effect in more humid environments. Within our database, we found that 42% of complexity studies, 41% of stocking rate studies and 29% of extended rest studies also reported at least some measure of soil carbon. Within the subset of cases where both infiltration rates and carbon were reported, response ratios were largely positive for both variables (at least 64% of cases had positive mean response ratios in all management categories). Overall, our findings reveal that a variety of management strategies have the potential to improve soil water infiltration rates, with possible benefits for soil carbon as well. However, we identified a shortage of well-replicated and detailed experiments in all grazing management categories, and call for additional research of both soil water and soil carbon properties for these critical agroecosystems.

Recent droughts in Puerto Rico and throughout the Caribbean have emphasized the region's agricultural vulnerability to this hazard and the increasing need for adaptation mechanisms to support sustainable production. In this study, we assessed the geographic extent of agricultural conservation practices incentivized by US Department of Agriculture Natural Resources Conservation Service (NRCS) and evaluated their large-scale contribution to drought adaptability. We identified concentrations of drought-related practices (e.g. cover crops, ponds) applied between 2000 and 2016. Using information from spatial databases and interviews with experts, we assessed the spatial correlation between these practices and areas exposed to drought as identified by the US Drought Monitor. Between 2000 and 2016, Puerto Rico experienced seven drought episodes concentrated around the south, east and southeastern regions. The most profound drought occurred between 2014 and 2016 when the island experienced 80 consecutive weeks of moderate drought, 48 of severe drought and 33 of extreme drought conditions. A total of 44 drought-related conservation practices were applied at 6984 locations throughout 860 km2 of farmlands between 2000 and 2016 through the NRCS-Environmental Quality Incentives Program (EQIP). Practices related to water availability were statistically clustered along the coasts, whereas soil and plant health practices were clustered in the mountainous region. While these concentrations strongly correlated with areas exposed to moderate drought conditions, >80% did not coincide with areas that experienced severe or extreme drought conditions, suggesting that areas highly exposed to drought conditions generally lacked drought preparedness assisted by EQIP. Climate projections indicate an increase in the frequency and intensity of drought events, particularly in the eastern region of Puerto Rico. Our analysis highlighted the need to implement more conservation practices in these areas subject to drought intensification and exposure. Government programs intended to address vulnerabilities and enhance capacity and resilience may not be reaching areas of highest exposure. Recommendations include raising producer awareness of past and future exposure and making programs more accessible to a broader audience.

Meeting the societal demand for food, bioproducts and water under climate change is likely to greatly challenge the maize-soybean agriculture of the Midwest USA, which is a globally significant resource. New agricultural systems are needed that can meet this challenge. Innovations in water management engineering and cropping system diversification may provide a way forward, enabling transformation to highly multifunctional agricultural watersheds that expand both agricultural production and water-related services to society, and which provide scalable units of climate adaptation in agriculture and water systems. Implementation and refinement of such watersheds require corresponding social innovation to create supportive social systems, in economic, political and cultural terms. A range of emerging social innovations can drive the emergence of highly multifunctional agricultural watersheds, by enabling robust cooperation, resource exchange and coordinated innovation across multiple societal sectors and scales. We highlight relevant innovations and opportunities for their exploratory implementation and refinement in the Midwest.

A large body of research has explored opportunities to mitigate climate change in agricultural systems; however, less research has explored opportunities across the food system. Here we expand the existing research with a review of potential mitigation opportunities across the entire food system, including in pre-production, production, processing, transport, consumption and loss and waste. We detail and synthesize recent research on the topic, and explore the applicability of different climate mitigation strategies in varying country contexts with different economic and agricultural systems. Further, we highlight some potential adaptation co-benefits of food system mitigation strategies and explore the potential implications of such strategies on food systems as a whole. We suggest that a food systems research approach is greatly needed to capture such potential synergies, and highlight key areas of additional research including a greater focus on low- and middle-income countries in particular. We conclude by discussing the policy and finance opportunities needed to advance mitigation strategies in food systems.