The present study reviews previous published estimates as to the scale of food waste in the USA and its ecological toll (e.g., in terms of methane emissions and water usage to support the production of wasted food). The review further discusses recent public policy and private action designed to curb food waste or to apply wasted food toward hunger alleviation, biofuel production and soil nourishment. We further consider and expand upon previous estimates comparing the scale of food waste to the present scale of the US hunger problem. These estimates suggest that the recovery and redirection of an additional 15% of the present stock of edible food waste would meet 35% of the caloric needs of all Americans living in a food insecure household or very low food security household. Then, a modest to moderate proportional increase in edible food waste recovery could greatly reduce the US hunger problem in its present state. We estimate that the successful redirection of 15% of presently-wasted (edible) food in the USA would be sufficient to fully sustain 18.45 million individuals. Given available data, we cannot precisely assess the nutritional characteristics of this potential stock of food. The present study emphasizes the traditional and future importance of integrated public policy and private action at the municipal level, as food waste is typically disposed of or recovered at this level.

The practice of grazing winter cereals before heading and subsequently harvesting the forage is common in some countries. Triticale (×Triticosecale Wittmack) is particularly interesting due to its nutritional characteristics, and forage yield and quality are strongly influenced by agronomic techniques. The effect of two modes of utilization (cut at heading stage and cut during winter grazing simulation with regrowth cut at heading stage), three nitrogen (N) fertilization levels [0 and 100 kg ha−1 split in two phases; and 100 kg ha−1 before sowing, using a fertilizer with 3,4-dimethylpyrazole phosphate (DMPP) as a nitrification inhibitor (NI)] and mycorrhizal fungus inoculation (mixed inoculation of Glomus intraradices and Glomus moseae) on forage yield and quality, protein fractions and in vitro digestibility of triticale was determined in southern Italy. Mode of utilization and fertilization affected significantly forage yield and quality, while mycorrhizal fungus inoculation influenced positively some quality parameters. Cutting at heading stage of triticale led to high dry matter (DM) production compared to the winter cut simulating grazing, but no differences in protein yield (PY). N fertilization increased total DM and PYs, but no differences were reported among the application modalities of N fertilizers. Triticale protein fractions and protein and fiber digestibility were improved by N fertilization. Mycorrhizal fungus inoculation positively influenced forage quality at heading stage, which resulted in more digestible fiber and protein. As a result, when triticale was grown under Mediterranean conditions, mode of utilization and N fertilization resulted in greater forage yield and quality, while mycorrhizal fungus inoculation influenced positively forage nutritional quality parameters.

Understanding the economics of organic agriculture is crucial to support of organic production by policy-makers and to facilitate producers converting their lands to organic production. The aim of this research was to compare organic and conventional hazelnut producers, in terms of their socio-economic characteristics, production systems and economic performance. The main data were gathered with surveys of 64 randomly selected conventional hazelnut producers and all the organic hazelnut producers (39) living in villages of the Terme district of Samsun, Turkey in 2005. Results revealed that, compared to conventional hazelnut producers, organic hazelnut producers were more educated, had larger hazelnut areas and spent more time on agricultural activities. The current research also used cluster analysis to define relatively similar farmers from both production systems and to compare variables. Organic producers needed more labor, especially hired workers, and used more lime, organic fertilizer and insect traps, while conventional producers used more synthetic inputs. Organic producers had lower costs of production and had higher income. It is recommended that the organic producers be supported financially, and assisted by research and extension services to produce and use their own inputs, rather than purchasing from outside. They should also be encouraged to establish associations to increase their marketing efficiency.

Agricultural biotechnology has been largely opposed by advocates in the sustainable agriculture movement, despite claims by the technology's proponents that it holds the promise to deliver both production (economic) and environmental benefits, two legs of the sustainability stool. We argue in this paper that participants in this polarized debate are talking past each other because assumptions about biotechnology and sustainability remain simplistic and poorly defined. Genetically engineered (GE) herbicide-resistant and insect-resistant crop varieties are the most visible current forms of agricultural biotechnology, and thus the form of biotechnology that many in the sustainability movement react to. However, these crops represent a biotechnology option that has paid insufficient attention to the integrated and systemic requirements of sustainable agriculture. In particular, common definitions of sustainable agriculture reinforce the need to include consideration of socio-economic distributive or equity effects into any assessment of sustainability. However, the frameworks that have been proposed to assess the potential for GE crops to enhance sustainable agriculture generally neglect this essential socio-economic dimension. We present an analysis that augments the sustainability frameworks to include the full suite of environmental, economic and social impacts. A review of the latest science on each impact category reveals that crop biotechnology cannot be fully assessed with respect to fostering a more sustainable agriculture due to key gaps in evidence, especially for socio-economic distributive effects. While the first generation of GE crops generally has made progress in reducing agriculture's environmental footprint and improving adopting farmers' economic well-being, we conclude that these early products fall short of the technology's capacity to promote a more sustainable agriculture because of the failure of those developing and promoting the technology to fully engage all stakeholders and address salient equity issues. To realize the sustainability potential of biotechnology will require fundamental changes in the way public and private research and technology development and commercialization are structured and operated. We identify new approaches in these areas that could make this powerful biological science more compatible with sustainable agriculture.

Cover crop mulches have been successful in reducing weed severity in organic soybeans. This study examined six rye cultivars (SRCs) used as cover crops to determine which were most adapted for use with a roller–crimper in the southeastern U.S. To be an effective mulch, a rye cultivar must produce high biomass and reach reproductive growth stage to facilitate mechanical termination via the roller–crimper prior to soybean planting. Rye cultivars were planted at three locations in North Carolina over the 2009 and 2010 growing seasons. Each rye cultivar was mechanically terminated via a roller–crimper implement. Rye cover crops were terminated on two dates and soybeans were immediately no-till planted into the mulch. In 2009, all rye cultivars produced greater than 9000 kg ha−1 rye biomass dry matter (DM) with the exception of Rymin at Plymouth (2009), but in 2010 only the early flowering cultivars produced in excess of 9000 kg ha−1 DM. There were no detectable soybean yield differences between the SRCs and the weed-free checks, and weed control was excellent across all SRCs at both Plymouth and Salisbury (2009). After an unseasonably cold and wet winter in 2010, the late flowering rye cultivars were not fully controlled by the early termination date due to delayed maturation (less than 65% control at 2 WAP) whereas the early flowering cultivars were fully controlled (100% control at 2 WAP). Rye biomass production was below 9000 kg ha−1 DM for the late flowering and dough development rye cultivars. The early-terminated rye plots had greater weed coverage across all SRCs than those from the late termination date (P < 0.01). However, weeds did not impact soybean yield for either of the termination dates. Soybean yield in 2010 was modeled with rye biomass and soybean population used as covariates, and for both termination dates, soybean yield was proportional to rye biomass production. Early flowering rye cultivars offer producers the widest range of termination opportunities that best coincide with their cash crop planting dates.

The fertility and soil health of organic agroecosystems are determined in part by the size and turnover rate of soil carbon (C) and nitrogen (N) pools. Our research contrasts the effects of best management practices (BMP) (reduction in soil disturbance, addition of organic amendments) on C and N cycling in soils from two field sites representing five organic agroecosystems. Total soil organic C (SOC), a standard measure of soil health, contains equal amounts of biologically and non-biologically active C that is not associated with release of mineral N. A three-pool first-order model can be used to estimate the size and turnover rates of C pools but requires data from a long-term incubation. Our research highlights the use of two rapid C fractions, hydrolysable and permanganate (0.02 M) oxidizable C, to assess shifts in biologically active C. Adoption of BMP in organic management systems reduced the partitioning of C to the active pool while augmenting the slow pool C. These pools are associated with potentially mineralizable N supplied by residues, amendments and soil organic matter affecting the concentration and release of mineral N to crops. Our data show that minimizing disturbance (no tillage, pasture) and mixed compost additions have the potential to reduce carbon dioxide emissions while enhancing slow pool C and or its turnover, a reservoir of nutrients available to the soil biota. Use of these rapid, sensitive indicators of biological C activity will aid growers in determining whether a BMP fosters nutrient loss or retention prior to shifts in total SOC.

Are strong local food systems better for the environment than conventional food systems where relatively close proximity between points of production and consumption is not a defining characteristic? Despite growing support for efforts to strengthen local food systems, surprisingly little is known about the relationship of local food to environmental sustainability. In particular, the relationship of local food systems to the use of agricultural chemicals to manage pests, weeds and disease has not been a subject of systematic research. In this paper, I use longitudinal data from the US Census of Agriculture to explore whether growth in local food systems is associated with decreased on-farm use of agricultural chemicals. Drawing on county-level data from 1997 to 2012, I find that an increase in the strength of local food systems—whether measured as the number of farms that market products directly to consumers, or as the total value of direct market products—has been broadly associated with a decrease in spending on agricultural chemicals in the USA as a whole. But the magnitude of the relationship between direct marketing to consumers and changes in agricultural chemical use has dwindled over time, to the point where it is not clear whether contemporary local food systems are still incentivizing farmers to reduce their use of pesticides. Overall, this study lends new credence to the idea that robust local food systems can benefit the environment. But even where just one dimension of agriculture's impact on the environment is concerned, the characteristics of local food systems appear to have varied over time—a qualification that argues strongly for further research into the relationship of local food to agricultural practice.

The following study assesses cold-season hoop house lettuce production in the context of local food systems’ relative environmental effects. For this purpose, we compare the carbon footprints of leaf lettuce production in two climatic zones, one close to the consumer market and one distant, via environmental impact modeling in SimaPro 7.3. A site-specific scenario is first detailed with organic leaf lettuce locally grown in an East Lansing, Michigan hoop house. This is compared to a hypothetical scenario, modeled using average industry data, with leaf lettuce conventionally grown in California then shipped to East Lansing. The system boundaries used in this analysis extend from manufacturing of farm production inputs to a hypothetical retail gate. We assumed that the consumer drove the same distance to the retailer in each case. The functional unit used is 1 kg of leaf lettuce. Results demonstrate that the distant system exhibits 4.3 times the CO2 ‘footprint’ per kg of lettuce. This nonlocal system also resulted in higher resource depletion, health impact and ecological damage potential as demonstrated via the SimaPro simulation. This study concludes that unheated, hoop house lettuce production, given the assumption on within-area travel, has a smaller carbon footprint than outdoor, distant production, and speaks to both the potential value of more localized food systems and the need for a more diverse set of scenario modeling to understand the boundaries of this value.

Perennial grain crops are an example of a ‘transformative technology,’ in which the functionality and science of the technology differ in a fundamental manner from conventional grain crops. A review of the literature indicates that the motivation for farmer adoption of transformative technologies is complex and poorly understood. At the same time, many studies have found concern and awareness about environmental issues to be significantly and positively correlated with the adoption of no-till agriculture, organic farming and agroforestry. Building on these insights, we conducted an ex ante study of perennial wheat adoption among 11 farmers from Michigan and Ohio. Perennial wheat is not yet commercially available, so a semi-structured interview format was chosen to allow for in-depth discussions of the crop's potential characteristics and uses. Consistent with the literature on transformative technology adoption, farmers who approached us to learn more about perennial grains described soil and environmental quality as their primary motivations for doing so. Farmers suggested a total of ten different uses for perennial wheat, only one of which was mentioned specifically by interviewers. This diversity of proposed uses implied a wide range of criteria for adoption. A striking result was that the ability of perennial wheat to compete with annual wheat on the basis of yield, a focus of researchers, was brought up by only one of the interviewees, as many farmers proposed perennial wheat as a means of solving a problem for which no other crop provided an adequate solution, often by planting perennial wheat on an under-used or marginal area of the farm. This is suggestive that interacting with farmers could alter priorities in perennial grain improvement, as has occurred in other radically transformative agriculture technologies.

In the past decade, sales of meat products labeled as natural (minimally processed) and produced without antibiotics and hormones have increased dramatically. In response to growing demand for meat products differentiated by various production attributes, many smaller-scale beef enterprises are considering direct marketing of their beef products to end-consumers as a viable approach to sustaining their family farming operations. This research uses survey data from Colorado consumers, and factor and cluster analysis to determine market segments for various (varied by production protocols and other meat attributes) natural beef products. Findings from the cluster analysis indicate that there are multiple segments of consumers who are likely to purchase natural beef, and that different segments are motivated by different factors. The most important factor explaining almost two-thirds of the differences among consumer responses relates to consumers' perceptions of the importance of meat attributes related to production practices (e.g. use of antibiotics, hormones and environmentally friendly grazing). Interestingly, the two consumer segments that are willing to pay a significantly higher premium for natural, local beef are motivated by different aspects of the meat and its intrinsic production attributes. One segment, representing 12.5% of consumers, ranked the importance of all production attributes significantly lower than the sample average. Consumers in this segment appear to be motivated by their perceptions of the extrinsic quality of natural beef products. The other segment, 13% of consumers, appears to be altruistic, ranking all production attributes such as ‘no antibiotics’, ‘no hormones’, and ‘humane treatment’, significantly higher than all of the other clusters. These results indicate the potential strength of production methods (and marketing of such quality differences) as product differentiation criteria. This paper illustrates the type of market research that may be useful for beef producers seeking value-added marketing opportunities, and portrays the types of consumers who are fueling the growth in natural meats in the United States. Such market analysis can facilitate producers' ability to effectively develop product concepts, labeling and promotional strategies targeted at the most receptive consumer segments, and illustrates that there is more than one type of consumer interested in purchasing products differentiated by sustainable production methods.

Grain and livestock production have gradually been separated, as farmers have tended to specialize in one or the other. Some producers and scientists are beginning to question whether this is the best approach. An integrated crop/livestock project was initiated in 1999 to investigate potentially beneficial synergies to both enterprises. The cattle portion of this project involved wintering dry pregnant cows on swathed crop residue and drilled corn produced in a 3-year crop rotation, with all crops present each year. Swath grazing was initiated in mid-November of 1999, 2000 and 2001, and terminated in mid-February each year. Two replications of ten Hereford cows were rotationally grazed on swathed oat/pea and triticale crop residue and swathed drilled corn (RGSC). Comparison treatments were: cows grazing swathed western wheatgrass (SWWG) and cows fed hay in a drylot. Cows on the RGSC treatment were also fed a 20% crude protein supplement of oat/pea and triticale grain. Drilled corn was swathed in late September and western wheatgrass in early October. Three-year average winter-long weight gains for the RGSC cows were slightly lower (P<0.10) than those for drylot cows. Body condition scores generally followed the same pattern as weight gain data. Reproductive and calf performance data were not significantly different among wintering treatments. Average daily feed costs per cow over the three winters were US$0.49, 0.65 and 0.73 for RGSC, SWWG and baled hay in a drylot, respectively, providing a potential daily savings of US$0.24 per cow with the RGSC treatment compared to bale feeding in a drylot. Swath grazing did not appear to have any adverse affects on mid-aged beef cow performance and could potentially reduce winter feeding costs and manure handling problems. The main problem with swath grazing is potentially deep snow and icing of the swaths.

Documentation of on-farm sustainability in agricultural sectors is becoming an essential element to ensure market access. An assessment process was developed to help soybean farmers document practices and verifiable advances in community, environmental and economic sustainability. Technical difficulties in analyzing and summarizing such assessment data include a large number of practices, correlation in variables, and use of discrete measures. By combining non-negative principal components analysis and common-weight data envelopment analysis, we overcame these difficulties to calculate a composite sustainability index for each individual farm and for the farm group as a whole. Applying this method to assessment data from 410 US Midwestern soybean farmers gave average sustainability scores of 0.846 and 0.842 for the soybean-specific and whole-farm assessments, respectively. Scenario analysis examined the impact if the bottom 10% of growers adopted the top ten sustainability drivers identified by the analysis. The average sustainability score only increased by 2%, but the minimum score increased from 0.515 to 0.647 for the soybean-specific assessment, and from 0.624 to 0.685 for the whole-farm assessment, while the lowest 10th percentile increased from 0.635 to 0.819 for the soybean-specific assessment, and from 0.634 to 0.920 for the whole-farm assessment. These results suggest that significant advancements could be made through focused efforts to improve adoption of sustainable practices by soybean farmers at the lower end of the spectrum.

A critical step in the quantification of soil quality (SQ) is the selection of SQ benchmarks. The benchmarks used in this study were SQ ratings made by 32 farmer collaborators representing a range of farming systems, scales of operation and geographic locations in the Mid-Atlantic region of USA. Soils from 45 pairs of sites identified by their farmers as having good and poor SQ were sampled over three seasons and analyzed for 19 soil parameters. Farmer judgments of SQ were based on many factors, most commonly soil organic matter, crop performance, soil water availability and erosion history. Selected individual soil parameters were normalized and integrated into an additive SQ index (SQI). Three additional indices were developed using discriminant analysis. The level of agreement between individual parameters, SQIs and farmer SQ ratings was evaluated using paired t-tests and mean percent difference values. The additive SQI was found to have the highest level of agreement with farmer SQ ratings (P<0.0001), demonstrating that a linear combination of soil parameters can be assembled that is more in agreement with holistic SQ criteria, such as farmer SQ ratings, than individual soil parameters. Extractable C from microwave (MW) sterilized soil (a measure of microbial biomass) was the individual parameter that best agreed with farmer SQ ratings (P<0.0001). Five additional soil C parameters, as well as aggregate stability, also agreed well with farmer SQ ratings (all P values <0.0005). The three parameters with the highest ratio of mean percent difference to coefficient of variation (an indication of parameter reliability) were extractable C from MW sterilized soil, anthrone reactive C and macroaggregate stability (14.2, 7.7 and 3.7, respectively). Mineral fertility parameters (pH, Ca, Ca:Mg ratio, P and K) were not significantly related to farmer SQ ratings (P values >0.05). The strong relationships observed between soil C parameters, soil structural parameters and farmer SQ ratings suggest that efforts to improve SQ in the study region should focus on monitoring and enhancement of soil C and soil structure.

There is limited documented scientific information on garden production systems managed in developing countries, partly because both researchers and research administrators have, until recently, ignored them as legitimate areas of study, and because such production systems have been regarded as informal production activities, managed outside conventional market and economic channels. Yet in a developing country such as Ghana, these production systems are potentially able to contribute substantially to the food security and health needs of households. This study was aimed primarily at providing critical scientific information for understanding the complex web of production and management factors associated with garden production systems. A total of 300 survey responses, representing the Sudan savannah, Guinea savannah and moist deciduous forest agro-ecological zones of Ghana, were analyzed (27% of respondents were females and 73% were males). Several hypotheses from the field agriculture literature were tested to determine their relevance in garden production systems. Although, for the country as a whole, a variety of garden crops are cultivated, each agro-ecological zone concentrated on a set of four major crops, with the actual food crops differing across agro-ecological zones. The type of protective fencing used was not statistically associated with land tenure (i.e., own versus rented land) status of the gardener (χ2=3.285, P=0.4501). Gender responsibilities in garden production and management tended to be more equally shared in the forest agro-ecology, where garden crops are cultivated for household consumption and for generating family income. In contrast, in the two savannah zones, adult males undertook a disproportionate share of activities to produce garden crops that were primarily for marketing. Valuable information on production and management exist within the traditional garden production systems studied, and range from socio-economic, agronomic and medicinal considerations in selecting garden crops and fruit trees, to ecological monitoring systems and strategies for garden management.

In recent years, the growth in local food marketing channels has been significant. Most of the research in this field examining the economic implication of these trends has focused post-farmgate including supply chain analysis (e.g., Hardesty et al., 2014; King et al., 2010), regional economic impacts (e.g., Brown et al., 2014; Hughes et al., 2008; Jablonski et al., 2016) and consumer values and motivations that have driven demand (e.g., Costanigro, 2014; Lusk and Briggeman, 2009). To date, with the exception of a few case studies examining expenses and sales by channel assessment (LeRoux et al., 2010; Hardesty and Leff, 2010; Jablonski and Schmit, 2016) there has been little research that examines the impact on financial viability among farms selling through these markets. The goal of this paper is twofold: first, to identify the factors that have the greatest influence on the efficiency of farmers and ranchers that participate in local food systems, and second, to estimate the relationship between marketing strategy and farm financial efficiency, with a particular focus on variations across farm size. Our estimation of the stochastic production frontier suggests that scale, production enterprise specialty, market outlet choices, land ownership, and management of expenses have the greatest influence on producer financial efficiency. Our model suggests that scale has the largest impact on financial efficiency, providing evidence that, all else constant, the most important factor in the efficiency of direct market producers is scale. When profit is defined as operating profit, results indicate that marketing channel is not an important indicator of efficiency. But when profit is defined as return on assets, marketing channel is an important indicator of efficiency, albeit less than is scale. Results from this analysis indicate there are economies of scale associated with farms and ranches that sell through local and regional markets, and that scale rather than marketing channel has the largest influence on efficiency.

Efficient nutrient use is critical to ensure economical crop production while minimizing the impact of excessive nutrient applications on the environment. Nitrogen (N) is a key component of agricultural production, both as an input to support crop production and as a waste product of livestock production. Increasing concern for future sustainability of agricultural production and preservation of the natural resource base has led to the development of nutrient budgets as indicators and policy instruments for nutrient management. Nutrient budgets for N have been developed by the Organization for Economic Co-operation and Development (OECD) as agri-environmental indicators to compare the evolving conditions in member states, and are also used by the US Department of Agriculture Natural Resource Conservation Service (USDA-NRCS) to develop nutrient management plans. Here, we examine the crop and animal production systems, drivers impacting management choices, and the outcome of those choices to assess the utility of gross annual N balances in tracking the progress of management decisions in minimizing the environmental impact of agricultural production systems. We use as case studies two very different agronomic production systems: Mississippi, USA and Poland. State and country level data from the US Department of Agriculture and OECD databases are used to develop data for the years 1998–2008, and gross annual N balances are computed. Examination of agricultural production practices reveals that the gross annual N balance is a useful tool in identifying differences in the magnitude and trends in N within agricultural systems over large areas. Significant differences in the magnitude of the N budget were observed between the highly diversified, small-scale agriculture common to Poland, and the large-scale, intensive agriculture of Mississippi. It is noted that use of N balance indices can be problematic if the primary intent is to reveal the impact of economic drivers, such as crop prices, or management choices, such as tillage or crop rotation. Changes in cropping systems in response to commodity prices that improve N balance can be masked by detrimental growing conditions, including edaphic, biotic and weather conditions, that are outside of the producers’ control. Moreover, use of large area-scale indices such as country or state-wide balances may mask the severity of localized nutrient imbalances that result from regionalized production systems that overwhelm the nutrient balance, such as confinement livestock production. Development of a policy to address environmental impact and establish sustainable production systems must consider the year-to-year variability of drivers impacting agricultural production, and the spatial heterogeneity of nutrient imbalance.

Public interest in local food continues to grow, but few analyses have examined the capacity for the US population to be supplied through local and regional food systems. This paper extends earlier work that demonstrated a method for mapping potential foodsheds and estimating the potential for New York to meet the food needs of the state's population centers. It provides a methodology for addressing the question, ‘If land is limited, which foods should be grown locally?’ A spatial model was developed to allocate the available agricultural land of New York State (NYS) to meet in-state food needs for six distinct food groups (grains, vegetables, fruits, dairy, meat and eggs) across the eight largest population centers. An optimization routine was used to allocate land to maximize economic land use value (LUV). Eleven scenarios were examined, ranging from a baseline level of consumption of New York produced foods to a 100% local diet. Across the 11 scenarios, the amount of food supplied, the LUV attained, and the area of land allocated increased as the ‘willingness’ to consume local products increased. This approach dictated that land was preferentially devoted to higher-value food groups relative to lower-value groups, and no scenario used all available land. Under the 100% local scenario, 69% of total food needs (on a fresh weight basis) were supplied in-state with an average food distance of 238 km. This scenario provided food from only four of the six groups, namely, dairy, eggs, fruit and vegetables. These results suggest that a much larger proportion of total food needs (on a weight basis) might be provided from in-state production than was found in previous work. LUV serves as a compelling optimization function, and future work should investigate the degree to which maximizing returns to land complements or conflicts with social and environmental goals of local and regional food systems.

Integrating cover crops into vegetable cropping systems can provide a wide range of ecological services, of which weed management is a key component. Cover crop effects on weed control, however, are dependent on termination methods and weed species present in specific cropping seasons. A 2-year weed management experiment with two cultivars of organic zucchini (Cucurbita pepo L.) in central Italy was carried out to compare the effect of a barley (Hordeum distichum L.) cover crop terminated with a modified roller-crimper (RC) to incorporated barley as green manure (GM) and a tilled control left fallow (FA) in the off-season. The effects of cover-crop management on crop competitiveness, yields and weed populations were evaluated by direct measurement, visual estimation and competition index methods. Results showed a significant reduction in weed biomass (>80%) and weed abundance with the RC compared to the GM and FA treatments. Moreover, the RC barley mulch maintained weed control in zucchini plots even under high weed pressure, as determined by the agronomic tolerance to competition (ATC) value of 67% in the RC treatment compared to 40 and 34% in the FA and GM treatments, respectively, averaged over both years of the experiment. The competitive balance (Cb), which quantified the ability of the zucchini crop to compete with weed populations, was also greater (+0.37) in the RC treatment compared to FA (−0.87) and GM (−0.69) treatments over the same period. Zucchini crop biomass was greatest in the RC treatment in 2011. Zucchini fruit yields varied from an average over both years of 1.4 Mg ha−1 in the RC treatment to 0.7 Mg ha−1 in the GM treatment, but yields in the FA treatment, 1.2 Mg ha−1, did not differ from the RC treatment. No differences in yield between ‘Dietary’ and ‘Every’ zucchini, or any significant interactions between cultivar and cover management related to fruit biomass, were observed. Our findings suggested the viability of the modified RC in creating a barley cover-crop mulch to effectively manage weeds and enhance yields in transplanted zucchini.

The paper reports on a study of community gardening in Stockholm. We contribute to the body of knowledge about the sustainability of community gardens and this new form of citizen-led initiatives in Stockholm, with the ambition of creating a debate about the best way to sustain and develop these initiatives in Sweden. We argue that although community gardening may provide leverage for means of developing a sustainable city, it is a marginal phenomenon and contributes little to sustainable development its present form. Through interviews we have investigated how the citizens and municipality officers of Stockholm try to adapt to the renewed interest in community gardening by looking at the policy makers’, municipality officers’ and grassroots movements’ incentives to start community gardens. We specifically focus on how the community gardeners articulate their reasons for participating in collaborative initiatives in the city and how these expectations evolve when they are faced with the reality of gardening and the problems relating to producing food in the city. We have found that there are a growing number of citizens and local authorities advocating community gardening, but the sustainability and endurance of gardens are hampered by vague responsibilities, lack of leadership and unclear expectations of the outcome. Community gardening cases in Stockholm contribute to the debate by exemplifying how formal (e.g. policy making) and informal advocacy (e.g. civic engagement in community gardening) groups are collaborating, but also showing that they often have different agendas and initial motivations for setting up new gardens. We argue that uncritical enthusiasm results in an overly instrumental approach to governance of community gardening and that the sustainability and endurance of the community gardening is not an issue that the governing bodies plan for, and hence it is forgotten. We suggest some routes forward, involving employing facilitators from various stakeholders such as the municipality, housing companies and various NGOs.

A field experiment was established to test the impact on crop yield, total productivity and biological di-nitrogen (N2) fixation of a self-regenerating annual legume, subterranean clover (Trifolium subterraneum L.), grown in mixtures with experimental perennial wheat lines. Legume content was altered in one intermediate wheatgrass (Thinopyrum intermedium (Host) Barkworth & Dewey) and two wheat (Triticum aestivum L.) × wheatgrass (Th. spp.) hybrid-based stands by sowing the legume in the same drill row as the perennial crop, or in every second or third row, spatially separated from the perennial crop. The hybrid perennial crops were more vigorous than intermediate wheatgrass in year 1, competing strongly and reducing legume biomass over the 2 yr period leading to reduced inputs of fixed nitrogen (N). However, both hybrid crops declined to negligible levels following the first summer with only the intermediate wheatgrass persisting in adequate densities in year 2. Spatially separating the perennial crop from the legume in alternate drill rows increased legume biomass by 32–128% and clover regeneration by 31–195%, and reduced weed incursion by up to 47% compared with where it was sown in mixed rows. However, spatial separation more than halved grain yields in year 2 compared with where the perennial crop was grown in every drill row. This likely reflected changed competition dynamics where the modified spatial configurations at sowing limited the perennial crops’ access to resources. When estimates of the total inputs of fixed N from the clover (5–165 kg N ha−1 in year 2) were compared with the amounts of N removed in grain by the different perennial wheat treatments (10–55 kg N ha−1 in year 1), it appears feasible that a companion legume could fix sufficient N to maintain the N balance of a cropping system producing 1.5–2.0 t grain ha−1 each year. The inclusion of a legume increased total above-ground biomass by up to 142%, particularly in year 2, but this did not translate into increased grain yields. It seems unlikely that a self-regenerating annual legume will be able to effectively coexist among a dense perennial wheat canopy where both species are sown in the same drill row. Further research is required to develop strategies to channel more of the additional resources apparently accessed by the companion legume into grain production.