Compost amendment in urban gardens: elemental and isotopic analysis of soils and vegetable tissues.

Urban horticulture poses a sustainable form of food production, fosters community engagement and mitigates the impacts of climate change on cities. Yet, it can also be tied to health challenges related to soil contamination. This work builds on a previous study conducted on eleven urban gardens in the city of Vienna, Austria. Following the findings of elevated Pb levels in some soil and plant samples within that project, the present study investigates the elemental composition of soil and plants from two affected gardens 1 year after compost amendment. Inductively coupled plasma mass spectrometry (ICP-MS) analysis of skin, pulp and seeds of tomato fruits revealed minor variations in elemental composition which are unlikely to have an impact on food safety. In turn, a tendency of contaminant accumulation in root tips and leaves of radishes was found. Washing of lettuce led to a significant reduction in the contents of potentially toxic elements such as Be, Al, V, Ni, Ga and Tl, underscoring the significance of washing garden products before consumption. Furthermore, compost amendments led to promising results, with reduced Zn, Cd and Pb levels in radish bulbs. Pb isotope ratios in soil and spinach leaf samples taken in the previous study were assessed by multi-collector (MC-) ICP-MS to trace Pb uptake from soils into food. A direct linkage between the Pb isotopic signatures in soil and those in spinach leaves was observed, underscoring their effectiveness as tracers of Pb sources in the environment.

Effect of Nutrient Solution Flow on Lettuce Root Morphology in Hydroponics: A Multi-Omics Analysis of Hormone Synthesis and Signal Transduction.

This study examined how the nutrient flow environment affects lettuce root morphology in hydroponics using multi-omics analysis. The results indicate that increasing the nutrient flow rate initially increased indicators such as fresh root weight, root length, surface area, volume, and average diameter before declining, which mirrors the trend observed for shoot fresh weight. Furthermore, a high-flow environment significantly increased root tissue density. Further analysis using Weighted Gene Co-expression Network Analysis (WGCNA) and Weighted Protein Co-expression Network Analysis (WPCNA) identified modules that were highly correlated with phenotypes and hormones. The analysis revealed a significant enrichment of hormone signal transduction pathways. Differences in the expression of genes and proteins related to hormone synthesis and transduction pathways were observed among the different flow conditions. These findings suggest that nutrient flow may regulate hormone levels and signal transmission by modulating the genes and proteins associated with hormone biosynthesis and signaling pathways, thereby influencing root morphology. These findings should support the development of effective methods for regulating the flow of nutrients in hydroponic contexts.

Knowledge, attitudes, and perceptions of farmers towards urban agroecology in Malaysia.

Adopting agroecological approaches to build resilient urban food systems has recently gained traction around the world, but there is little to no reliable literature on the knowledge, attitudes, and perspectives of urban farmers towards these nature-based solutions in many developing nations, including Malaysia. The present study conducted an online survey to determine the extent to which local urban farmers understand and employ agroecology, as well as to assess their awareness and views on using agroecological practices and sustainable farm management. We found that the majority of respondents are unfamiliar with agroecological principles, with 79 % agreeing or strongly agreeing that implementing sustainable agricultural practices is challenging. However, more than 90 % of respondents are aware of the environmental consequences of excessive input utilisation. Our findings highlight the need for improved initiatives to promote agroecological approaches among farmers by sharing knowledge and best practices. In light of the growing threat posed by urban heat islands and the rapid urbanisation, this study offers novel insights into the knowledge gaps and perceptions about agroecological approaches among urban farmers, challenges that must be addressed to promote sustainable agriculture, and the potential role of farmers in achieving the three fundamental pillars of sustainability-planet, people, and prosperity.

Linking policies and regulations to sustainable finance for the promotion of urban agriculture: Evidence from micro and small businesses.

Urban agriculture is closely tied to several of the Sustainable Development Goals. It can play a critical role in helping to achieve these goals by promoting sustainable food production and consumption, reducing greenhouse gas emissions, and creating more sustainable cities. It is also considered a pathway for overcoming food security in urban areas. However, this needs to be integrated with policies and regulations supported by sustainable finance. Due to COVID-19, conflict, and lack of infrastructure in Ethiopia, several challenges must be addressed to promote urban agriculture to aid food security. Hence, this study is conducted to examine how government policies and regulations promote urban agriculture through sustainable finance in Ethiopia. The study employed both an explanatory research design and a mixed research approach. Multi-stage sampling techniques that include (Simple random sampling techniques and judgmental sampling were used. The data was collected from selected micro and small enterprises engaged in urban agriculture. The structural and measurement model is estimated with the help of smart-pls software version 4. The study's finding implies that government policies and regulations have an insignificant effect on urban agriculture. At the same time, the study finding implies that sustainable finance has an important mediating role between urban agriculture and government policies. Hence, the impact of government policies and regulations on urban agriculture is found to have an indirect effect. Based on the study's findings, the study recommends that all stakeholders promote innovation and entrepreneurship that promote urban agriculture through sustainable finance.

The comparative advantage of urban goat production.

BACKGROUND: Urban agriculture significantly contributes to food security. The two primary components of urban agriculture are livestock production and horticulture. The goat, Capra hircus, is one of the commonly raised food animals. Goats can be used to generate income, produce milk, meat, skins, furs (hairs) and manure and provide various sociocultural and ecological services. OBJECTIVES: This study evaluates the significance of urban goat production and recommends ways to lessen the adverse impacts of urban goat production. METHODS: This report involved an in-depth interview with seven key informants in Adama and Addis Ababa cities. RESULTS: Goats can thrive in limited urban open spaces, scavenge leftovers from homes and open markets and browse on open public land. Goats can be incorporated into urban agriculture, in so doing contributing to a circular economy. Goats can thrive on a limited supply of water and feed and require less care and space. Goat farming is used to mitigate the adverse impact of climate change. Goats are naturally active, which makes them better at avoiding traffic accidents. Goats can be used to control bush encroachment. Goat farming in cities improves land use efficiency and food security. Being friendly animals, goats can be utilized to play with kids, and they can be a basic piece of metropolitan ecotourism. However, goats can harm urban green spaces; therefore, to avoid issues of this kind, goat production must be zoned. CONCLUSIONS: Urban goat farming could add a new dimension to urban food security. Extensive pieces of empirical evidence need to be generated to enhance the adoption of urban goat farming.

Afetividade pessoa-ambiente nas hortas comunitárias: promoção da saúde e da sustentabilidade / People-environmental affectiveness in community gardens: health and sustainability promotion

RESUMO As hortas comunitárias inspiradas em modelos agroecológicos já são tendências nas cidades que buscam estimular ambientes positivos. Entre as possíveis estratégias, permitem integrar políticas que visam à erradicação da fome, a garantia de qualidade alimentar e o aumento da economia familiar. O presente estudo objetiva analisar os significados simbólicos e afetivos dos usuários diante de suas atividades nas hortas comunitárias urbanas. Foram 40 entrevistados com idade média entre 45 e 80 anos, por meio do Instrumento Gerador de Mapas Afetivos. A pesquisa foi realizada in loco e os participantes foram convidados a desenhar a horta e responder à entrevista. As imagens produzidas foram analisadas a partir de suas estruturas, sentimentos e sentidos. Constatou-se que as vivências nesses ambientes foram mediadas por sentimentos de agradabilidade, pertencimento e restauração. Entre os sentidos atribuídos, destacaram-se a conexão com a natureza e a interação social. Conclui-se que tais dimensões presentes nas hortas estudadas podem contribuir para a promoção da saúde, da sustentabilidade e a preservação ambiental.

ABSTRACT Community gardens inspired by agroecological models are trends in cities that seek to stimulate positive environments. Among the possible strategies, they allow us to integrate policies that aim to eradicate eradicate hunger, guarantee food quality and increase the family economy. This study aims to analyze the symbolic and emotional meanings of users during their activities in urban community gardens. There were 40 interviewees with average age between 45 and 80 years old, through the Affective Map Generator Instrument. The research was carried out on site and the participants were invited to develop the information and respond to the interview. The images produced are analyzed from their structures, feelings and senses. It is confirmed that experiences in these environments are mediated by feelings of pleasantness, belonging and restoration. Among the senses attributed, the connection with nature and social interaction stand out. It is concluded that these dimensions present in the studied gardens can contribute to the promotion of health, sustainability and environmental preservation.

Residents' preferences for urban agriculture in Shanghai.

Although urban agriculture (UA) has been gaining greater attention as part of an effort toward sustainable urban development in China, empirical knowledge is limited. We conducted a discrete choice experiment with 756 residents of Shanghai. Overall, the results indicate that respondents supported UA as they tended to favor one of the UA scenarios presented. Residents prefer UA facilities that utilize environmentally friendly production, offer farming activities, and are equipped with dining facilities. Regularly scheduled educational activities hosted by UA facilities are preferred to those on an irregular basis. In terms of location, residents prefer UA facilities that are close by but do not necessarily want UA facilities to be right in front of them. There is a stronger preference for UA among highly educated populations, those with primary and secondary school students, and those with agricultural work experience. Additionally, various UA attributes affect residents' preferences; overall, there is a high degree of homogeneity in residents' preferences for various UA attributes. The marginal willingness to pay value is slightly higher than expected among the estimation results. There are three reasons for this outcome: the characteristics of UA as a recreational facility in China, the relatively high price level in Shanghai, and the impact of the COVID-19 pandemic.

Spatial Barriers to Transforming toward a Healthy Food System in the Noreste of Mexico.

In the past five decades, global food systems have undergone a notable transition, moving from predominantly rural settings to increasingly urban and industrialized environments, largely driven by processes of globalization and supply chain integration. However, this evolution has not adequately addressed equitable access to nutritious diets and food environments, resulting in adverse health outcomes. This study delves into the spatial and non-spatial barriers that impede the adoption of healthy diets in the Noreste of Mexico, particularly focusing on the challenges associated with accessing and cultivating plant-based foods. Through an examination of suitable areas for urban agriculture and an exploration of the socio-cultural factors influencing the adoption of plant-based diets, the research focuses on interventions aimed at promoting healthier and more sustainable eating practices in Monterrey. The findings of the study reveal significant disparities in food access across the Monterrey metropolitan area, with central urban zones exhibiting superior access to fresh foods compared to suburban and peripheral regions. This inequality disproportionately affects marginalized areas characterized by higher poverty rates, exacerbating issues of food insecurity. Nevertheless, traditional dietary practices could offer promising avenues for creating culturally significant and healthier dietary transitions, even amidst the ongoing process of urbanization.

Elucidation of heavy metal content, phenolic profiles, and antioxidant activities of kale (Brassica oleracea L. var. acephala) and arugula (Brassica eruca L.) grown in urban gardens in Istanbul.

This study was conducted to evaluate the effect of two distances: close (0-10 m) and far (60 m) from the heavy traffic roadside, at three different cultivation sites (MS: Mevlanakapi-Silivrikapi, SB: Silivrikapi-Belgradkapi, and BY: Belgradkapi-Yedikule kapi) along the road line. First, the phenolic compounds, antioxidant activity, and physicochemical properties in kale and arugula vegetables were examined. Second, heavy metal concentrations in vegetables, soil, and irrigated water were investigated. In both vegetables, the highest total phenolic content was detected in samples obtained from far distance in SB site (3880.3 mg/kg) for kale and in BY site (1459.9 mg/kg) for arugula, whereas the lowest content was found at the close distance in MS site for both kale (448.5 mg/kg) and arugula (586.4 mg/kg). The antioxidant activity values [mg Trolox/kg (dw)] ranged from 366.74 to 586.10 and 2349.00 to 3757.4 for kale and from 520.00 to 945.60 and 3323.00 to 5814.70 for arugula in 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) and 2,2-diphenyl-1-picrylhydrazyl methods, respectively. The levels of Cd and Hg in kale and arugula and Fe content in arugula exceeded FAO/WHO permissible limits, making them unsafe for human consumption. Meanwhile, the Pb content in kale and arugula and Fe content in kale were observed to be within acceptable limits set by FAO/WHO. In the irrigated water, the Pb value was below the permissible limit, whereas the Cd value was above it and no Hg and Fe were detected. In the soil samples, the Pb and Fe values were below the limit, whereas the Cd and Hg values were higher.

Fresh bell peppers consumed in cities: Unveiling the environmental impact of urban and rural food supply systems.

Agriculture and its supply chain pose significant environmental threats. This study employs Life Cycle Assessment (LCA) to explore the environmental impact of fresh bell pepper production and distribution, comparing Urban and Peri-Urban Agriculture (UPA) with Rural Long-Distance Food Supply Systems (RLDFS). Four UPA scenarios (hydroponics, soil-based greenhouse, open-field conventional, and organic) and two RLDFS scenarios (soil-based greenhouse and open-field conventional) are evaluated using SimaPro, incorporating inputs from UPA practitioners and rural farmers. Results reveal an energy demand range of 0.011 to 5.5 kWh/kg eq., with urban greenhouses exhibiting the lowest consumption and hydroponics the highest due to lighting, ventilation, and irrigation. Hydroponics exhibits a global warming potential of 7.24 kg of CO2 eq·kg-1, with energy demand contributing over 95 %, surpassing other scenarios by 7-25 times, necessitating reduction for sustainability. RLDFS's environmental impact is dominated by transportation (over 70 %), meanwhile other UPA systems are influenced by irrigation, infrastructure, and fertilizers. Despite challenges, UPA-hydroponics proves to be 1.7 to 4.3 times more land-use-efficient than other scenarios, emphasizing its potential. The study highlights the need to address electricity usage in UPA-hydroponics for carbon footprint reduction. Despite challenges, hydroponics could contribute to sustainable food security, and RLDFS does not significantly lag in environmental performance compared to UPA other than Ozone layer depletion criteria attributed to fossil fuel usage in transportation. These insights offer valuable guidance for urban development and policy formulation, promoting sustainable agricultural practices and supporting policies for agronomic and supply chain sustainability.

Unexpected effects of urban food activism on community and human wellbeing.

Participation in urban agriculture conducted through community gardens and allotments is known for its benefits to physical and mental health. Due to the recognition of these benefits, which include reduction of stress, depression and anxiety, such participation is increasingly being prescribed as a non-medical health intervention. Community gardens have the added advantage of immersion into a community, without the often-long waiting lists and level of commitment involved in allotment tenancies. What has not been explored is the demanding nature of the commitment required by volunteer coordinators, and ironically, the negative effects it can have on their wellbeing. In a study of food activism in Aberdeen, UK, we conducted 21 semi-structured interviews with participants from a range of bodies involved in the city's food growing projects. From the spectrum of food growers, we found that volunteer coordinators of community gardens experienced the greatest burdens on their time and wellbeing, with their demanding multi-functional roles leading to fatigue and feelings of over-commitment. Other problems encountered by community gardeners were over-reliance on grant funding and the disproportionate impacts of COVID closures on vulnerable groups. Policy interventions are required to reduce dependency on competitive grant funding and to support both coordinators and the long-term sustainability of community gardens.

Does urban agriculture contribute to food security, and how might this be achieved?

OBJECTIVE: Food system challenges exacerbate inequalities in access to fresh healthy food and threaten food security. Lack of food security, referred to as food insecurity, is associated with poorer physical and mental health outcomes and has been identified as a key challenge to address by calls for food system transformation. Increasing food production through urban agriculture, the production of fruit and vegetables in urban areas, has been identified as a potentially effective contributor to food system transformation, but the effect of this on household or UK-level food security is unclear. This paper reviews international evidence of urban agriculture's impact on food security. DESIGN: Narrative review. SETTING: This paper reviews international evidence of urban agriculture's impact on food security. PARTICIPANTS: Previously published international research. RESULTS: Whilst findings are mixed, available evidence suggests that urban agriculture makes a modest, yet positive, contribution to food security by facilitating the availability of and access to fresh fruit and vegetables to food insecure households. CONCLUSIONS: Capitalising on the potential for urban agriculture to benefit food security requires government investment and support at both the national and local levels; therefore, increasing access to land for food growing, reducing costs of related resources and collaboration with existing community groups to enhance sharing of skills and expertise are identified as avenues for exploration that may help to achieve this. This review also highlights opportunities for future research in this field that may strengthen the quality of the evidence supporting urban agriculture's impact on food security.

Evaluation of the consumption of agricultural and urban waste by the diplopod Trigoniulus corallinus as a strategy for formulating new combinations for the millicomposting process.

This study aimed to measure the consumption of different types of plant waste by the diplopod species Trigoniulus corallinus, in order to determine which would be the most suitable for the millicomposting process. To this end, a waste consumption experiment was carried out in the laboratory, using a completely randomized experimental design with 15 replicates and 13 organic residues from different sources. After 10 days, the following parameters were evaluated: dry mass of the waste used to feed the diplopods, dry mass of the fecal pellets, and diplopod mortality. Significant differences were observed in the consumption rates of the diplopods in the different treatments, with the highest rates being observed for Mimosa caesalpiniifolia, with 44.49%, followed by Gliricidia sepium chips, with 38.24%. The highest values for pellet mass were obtained from the decomposition of Mimosa caesalpiniifolia litter (0.891 g). The treatment with Syngonium auritum shavings showed 93% mortality after consumption, followed by the treatment with Heliconia psittacorum shavings, which showed 53%. Both species are ornamental and widely found in gardens and backyards. The diplopods have a preference for Mimosa caesalpiniifolia litter and Gliricidia sepium shavings. There is limited consumption of ornamental plant waste, with reports of toxicity to other organisms. Based on these results, a mixture of waste will be tested for millicomposting in urban farming areas that excludes toxic plants.

Determinants of adoption of urban agricultural practices in eastern Haraghe zone of Oromia region and Dire Dawa City administration, eastern Ethiopia.

Although urban agriculture (UA) can aid economic development, food inflation, unemployment, and nutritional insecurity often necessitate urban households to engage in various agricultural practices. Hence, the study aimed to identify UA practices adopted and their determinants in the Eastern Haraghe zone of the Oromia region and Dire Dawa City Administration, Eastern Ethiopia. Data was collected from 385 randomly selected urban households using a semi-structured questionnaire. Descriptive statistics and a Multivariate Probit (MVP) model were used to analyze the data. The results of the MVP model reveal that sex, age, education level, land size, extension contact, credit access, community group participation, training, and household non-farm income significantly influenced vegetable farming adoption. On the other hand, livestock production adoption was also affected by factors such as sex, land size, perception, credit access, farming experience, community group participation, market distance, training, and non-farm income. Crop-fruit production adoption was also influenced by factors like age, perception, farming experience, market distance, training, and dependency ratio. Improving the ability to use the land for UA purposes, empowering female-headed households, improving livestock breeds, creating awareness through short-term training, and improving credit accessibility are important recommendations to enhance the adoption of UA practices in the study areas.

Pesticide residue and dietary intake risk of vegetables grown in Shanghai under modern urban agriculture in 2018-2021.

Shanghai as an international metropolis is representative of modern urban agriculture in China, so it is of great significance to analyse the pesticide residue in vegetables grown in Shanghai. This study investigated the residue of 68 commonly used pesticides (divided into insecticides, fungicides, herbicides and plant growth regulators) in 7028 vegetable samples in Shanghai from 2018 to 2021, and estimated the dietary intake risk of these pesticides. These samples were divided into 6 categories. A total of 29.21% of vegetable samples had pesticide residues, and 0.47% of samples exceeded the maximum residue limits (MRLs) set by the national food safety standard of China. Leafy vegetables had the highest detection rate of pesticide residues (32.9%), multiple detection rate (12.2%), pesticide residue concentration (35.7 mg/kg), and the number of samples exceeding the MRL (30). There were 36 out of 68 pesticides detected in vegetables, and the top 3 were dimethomorph, propamocarb and acetamiprid. The target hazard quotient (THQ) and hazard index (HI) of these noticeablepesticides were all less than 1, illustrating that there may be no obvious health hazard for residents exposed to the pesticide levels. This study can promote the green development of the pesticide industry and provide important reference data for the monitoring of pesticide residues and their hazards under modern urban agriculture.

Municipal Compost Public Health, Waste Management, and Urban Agriculture: A Decadal Study of Fugitive Pb in City of Boston, Massachusetts, USA.

Compostable materials constitute roughly half of waste generated globally, but only 5% of waste is actually processed through composting, suggesting that expanding compost programs may be an effective way to process waste. Compostable waste, if properly collected and processed, has value-added end use options including: residential and park landscaping, remediation of brownfield sites, and as growing media in urban agriculture (UA). Since 2001, our lab has partnered with The Food Project, a non-profit focused on youth leadership development through urban farming. From 2006 to 2022 we collected compost materials that were delivered to the farm from a variety of local sources and analyzed a suite of biogeochemical properties including lead (Pb) concentrations, organic carbon, and grain size distribution. Pb concentrations of Boston's municipal compost always exceeded the current City of San Francisco soil and compost purchase standard (80 µg/g). In 2012 Boston's composting program was halted when it exceeded the 400 µg/g Environmental Protection Agency's Pb in soil benchmark. Urban Pb is geomobile and must be managed to minimize resuspension and transport of fines whose Pb concentration is often elevated compared to bulk compost. Consequently, urban farmers have to source lower Pb compost from suburban suppliers at significantly greater cost. Over a 15 year period and through several city vendor contracts, Pb concentrations in municipal compost remain at levels that warrant continued surveillance and risk assessment.

Local Habitat Complexity and Its Effects on Herbivores and Predators in Urban Agroecosystems.

In urban community gardens, cultivated vegetation provides variable levels of habitat complexity, which can suppress pests by promoting predator diversity and improving pest control. In this study, we examine three components of the structural complexity of garden vegetation (cover, diversity, and connectivity) to investigate whether higher garden vegetation complexity leads to fewer herbivores, more predators, and higher predation. We worked in eight community gardens where we quantified vegetation complexity, sampled the arthropod community, and measured predation on corn earworm eggs. We found that plots with high vegetation cover supported higher species richness and greater abundance of predatory insects. High vegetation cover also supported a greater abundance and species richness of spiders. In contrast, high vegetation diversity was negatively associated with predator abundance. While high predator abundance was positively associated with egg predation, greater predator species richness had a negative impact on egg predation, suggesting that antagonism between predators may limit biological control. Community gardeners may thus manipulate vegetation cover and diversity to promote higher predator abundance and diversity in their plots. However, the species composition of predators and the prevalence of interspecific antagonism may ultimately determine subsequent impacts on biological pest control.

Advancing rainwater treatment technologies for irrigation of urban agriculture: A pathway toward innovation.

Urban agriculture (UA) has emerged for local food security since the 1960s. However, the access to sufficient and safe irrigation water remains a significant constraint. Municipal water supply, though commonly used in UA practices, proves unsustainable due to high costs, intensive energy consumption, and limited availability in many vacant urban spaces. In contrast, rainwater harvesting (RWH) exhibits a potential as a non-traditional water supply for urban farming. This article aims to provide insights into the advantages and challenges associated with RWH for UA irrigation, analyze existing low-cost RWH treatment technologies, and identify a visionary way toward innovative, new-generation RWH treatment processes in UA practices. Despite a promising water source, harvested rainwater is challenged for crop irrigation owing to the presence of various contaminants (e.g., waterborne pathogens, potentially toxic metals and metalloids, and synthetic organic chemicals). While established RWH treatment processes (e.g., first flush diversion, sedimentation, solar disinfection, chlorination, UV irradiation, granular filtration, and bio-sand filtration) can remove certain pollutants, they cannot offer viable treatment solutions for UA irrigation due to different technical, economic, and social restrictions. Particularly, their capacity to reliably remove contaminants of emerging concern in runoff remains limited or uncertain. Consequently, it is essential to develop next-generation RWH treatment technologies tailored specifically for UA irrigation. To this end, three fundamental principles are recommended. First, the focus should be on technically viable, low-cost, simple-operation, and easy-maintenance treatment technologies capable of simultaneously addressing traditional and emerging runoff contaminants, while minimizing the production of undesirable treatment byproducts. Second, advancing the understanding of the water, soil, and crop interactions enables the development of "right" RWH treatment processes for irrigation of "right" crops at a "right" place. Last, crop nutrients, if possible, are retained in rainwater to reduce the nutrient demand for crop production. The insights and perspectives have far-reaching implications for water conservation, stormwater management, and the integration of water, food, and energy systems within the urban environment.

Measuring BVOC emissions released by tomato plants grown in a soilless integrated rooftop greenhouse.

Urban design is currently promoting the inclusion of plants in buildings. However, plants emit biogenic volatile organic compounds (BVOCs), which alone or in combination with other airborne molecules such as CO2, may result in a general increase in tropospheric pollution. Many studies have documented the effects of biotic and abiotic factors on plant BVOC responses, but few have assessed the contribution of typical CO2 levels found in indoor work and meeting spaces. To answer this question, we monitored CO2 and constitutive (MT-limonene) and induced (LOX-cis-3-hexenal) BVOC emissions of a fully developed tomato crop grown hydroponically inside an integrated rooftop greenhouse (i-RTG) in a Mediterranean climate. Two distinctive CO2 assays were performed at the level of the i-RTG by supplying or not CO2. The impact of CO2 on plant physiological emittance was then assessed, and the resulting BVOC rates were compared with reference to EU-LCI values. MT-limonene was ubiquitous among the assays and the most abundant, while LOX-cis-3-hexenal was detected only under controlled CO2 management. The highest levels detected were below the indicated LCIs and were approximately tenfold lower than the corresponding LCI for MT-limonene (50.88 vs. 5000 µg m-3) and eightfold (6.63 µg m-3) higher than the constitutive emission level for LOX-cis-3-hexenal. Over extended sampling (10 min) findings revealed a general emission decrease and significantly different CO2 concentration between the assays. Despite similar decreasing rates of predicted net photosynthesis (Pn) and stomatal conductance (gs) their correlation with decreasing CO2 under uncontrolled condition indirectly suggested a negative CO2 impact on plant emission activity. Conversely, increasing CO2 under the controlled assay showed a positive correlation with induced emissions but not with constitutive ones. Because of significantly higher levels of relative humidity registered under the uncontrolled condition, this factor was considered to affect more than CO2 the emission response and even its collection. This hypothesis was supported by literature findings and attributed to a common issue related with the sampling in static enclosure. Hence, we suggested a careful monitoring of the sampling conditions or further improvements to avoid bias and underestimation of actual emissions. Based on the main outcomes, we observed no evidence of a hazardous effect of registered CO2 rates on the BVOC emissions of tomato plant. Furthermore, because of the low BVOC levels measured in the i-RTG, we assumed as safe the recirculation of this air along building's indoor environments.

Understanding and supporting intermediation work to address territorialized public policy issues: The case of a Territorial Food Project in France.

BACKGROUND: Few ergonomics studies have explored the work required to implement territorialized public policies. OBJECTIVE: To identify key challenges for ergonomists who analyse and support intermediation work taking place in the design and implementation of a Territorial Food Project or TFP (a public policy device). METHODS: We adapted a framework developed in the field of political sociology. The analysis focuses on two scales to identify key characteristics of intermediation work: the agri-urban area as delimited and targeted by the TFP; and the farm and its relationships to food systems. To capture how intermediation work articulates prescription and action, we studied first the work carried out by the actors to use a public policy device such as TFP, and second the evolving farming work systems' connections to food systems and how they are supported by various actors. RESULTS: Intermediation work is spread across a wide diversity of actors. Coordination at governance level aims to allocate resources among institutional actors and to check the progress of the elaborated action plan. Coordination at operational level, which is meant to support farming work system dynamics or to implement the action plan, focuses on fostering the emergence of initiatives but seems to lack a shared vision and time availability. CONCLUSION: We identify two main challenges: to further develop a framework for analysing the intermediation work occurring in a multi-scale and territorial perspective; and to develop new intervention methods so that ergonomists can take part in and support such intermediation work.