Manufactured biobased mulch (biomulch) films and fabrics are useful non-chemical weed management tools, but are not typically used for high-density plantings of vegetables such as lettuce (Lactuca sativa L.) and carrot (Daucus carota L. subsp. sativus). However, it may be possible for crop roots to grow through a permeable biomulch membrane. Our objective was to demonstrate the potential for lettuce and carrot to germinate on and grow through biomulch, and assess changes in crop growth and yield. Biomulches included a 100% polylactic acid (PLA) biofabric and a PLA (37%) + soybean meal (63%) biofabric (PLA + SOY). Seeds were placed directly on biomulch and top-dressed with a soil mix or compost. Crop roots grew through the biomulch (despite visible constriction in carrot), and total yields were either the same or greater than those in the no-mulch control. PLA + SOY increased lettuce yield by 72% and also degraded faster than the PLA mulch. Results hold promise for improving weed control and reducing labor in high-density vegetable plantings.

Corn earworm (Helicoverpa zea) is one of the most important pests in organic sweet corn (Zea mays) production. Breeding of corn earworm-resistant varieties has been identified as a potential approach to deal with this pest, but it is critical that plant breeding efforts reflect the contexts and needs of organic producers who might eventually adopt earworm-resistant varieties. In November–December 2017, we surveyed organic sweet corn producers in the U.S. to learn about impacts of corn earworm on organic sweet corn production, how producers are currently managing the pest and opportunities for plant breeding to reduce its overall impact. The survey confirmed that corn earworm is the most challenging insect pest for organic sweet corn producers, that current management options remain limited and that earworm-resistant varieties could improve the ability of growers to consistently produce damage-free sweet corn and to improve the value of sweet corn within organic operations.

In agricultural regions, like Whatcom County, Washington, crop and dairy production co-exist, but increased agricultural specialization and intensification have divorced what was, historically, an integrated approach to production. This agricultural segregation contributes to farm, regional and watershed-scale nutrient imbalances, and several different management approaches have been devised to improve, correct and close these nutrient cycling disparities. In high-density production regions, utilizing locally produced bio-based fertilizers may provide one avenue toward closing regional nutrient loops. Technologies such as dairy-operated nutrient recovery systems may help improve the flow of nutrients between dairy and cropping systems by extracting nutrients from raw manure and producing materials that are more easily used on farms than raw manure. To evaluate the potential impact of a nutrient recovery system and its related product, we estimated nitrogen balances between cropland use and manure production within Whatcom County, Washington and examined a theoretical scenario in which a specific nutrient recovery product was utilized across the region. We considered one economic barrier, transportation cost, and calculated a hypothetical comparison for transporting nitrogen in two forms, a downstream nutrient recovery product and raw manure. The scenarios presented here demonstrate a potential gap between regional nutrient supply and demand, illustrate the tradeoffs with a technological approach, and make clear that both technological tools and practical management strategies are needed to address the challenges of redistributing nutrients in high-density production areas.

Green manures are a promising alternative for achieving the sustainable production of maize in the face of low soil fertility and increasingly long canicule periods, particularly in rainfed systems associated with the reproduction of local agrobiodiversity. However, it is necessary to investigate what are the advantages and disadvantages associated with different species of native and exotic pulse, as well as their overall contribution to the sustainable production of maize landraces. In order to do so, we followed the MESMIS method to assess five species of pulse (three native and two exotic) grown with maize in two plots with different soil conditions. This was done in the seasons of 2017 and 2018 the municipality of Villa de Zaachila, Oaxaca, a site with remarkable biological, agricultural and cultural diversity. A fully randomized complete block design was implemented with 11 treatments and three repetitions in the two plots. The output variables of the experiment were: land equivalence ratio, interspecific aggressiveness, content of soil organic matter, decomposition rate, plant survival rate and plant dry biomass. We also evaluated quantitative or qualitative indicators of cost, adaptability and contribution to food security. For all the possible maize-pulse combinations, except for one, polyculture outperformed maize and pulse monocultures. Exotic pulses (Crotalaria junscens spp. and Dolicho lablab) had a better performance in biomass, reincorporation of organic matter and possible nitrogen fixation, as well as greater resistance to drought in the second cycle. The native pulses (Phaseolus vulgaris and Phaseolus coccineus), however, had a greater acceptance and economic output and are important for the food security in our study site. Our results provide quantitative and qualitative elements to design combined schemes of green manures associated with maize that would help tackle current challenges regarding maize productivity, food security and response to climate change.

The aim of this paper is to present and discuss a new approach to assess a city's supply with food from the nearby region: the city food flow analysis. In view of the growing challenges of the global food system, the local level has increasingly been identified—both by citizen-consumers and city administrations—as a relevant scale to develop sustainable alternatives. Although different actors often agree on the aim to increase local food supply, the discussions and initiatives convey the lack of knowledge and data about the actual origin of food supplied to cities. Without knowing where food comes from and through which channels it reaches the consumer, it is difficult to develop alternatives that could eventually change the food system. This paper presents and discusses the city food flow analysis as a methodology to close this lack of information. It consists of a four-step approach that leads to a clear picture on the local food production around a city, the consumption of local food in a city and the importance of different supply chains for local food in the city, including retail and gastronomy. The methodology is illustrated with the example of two cases (cities). The city food flow analysis provides detailed information about the current situation of urban food provisioning, which city stakeholders can use to start an informed discussion process about necessary changes in the food system, re-embedding of cities into their territorial context. However, data are not always fully available, which is a result in itself that illustrates the challenges of re-localizing local food provisioning.

Changed spatial configurations at sowing have been investigated as a strategy to minimize interspecific competition and improve the establishment and persistence of multi-species plantings in pastures, but the impact of this practice on the soil microbiome has received almost no previous research attention. Differences in populations of bacteria and fungi in the surface 10 cm of soil in the third year following pasture establishment were quantified using quantitative polymerase chain reaction and terminal restriction fragment length polymorphism methods. Populations were compared on, and between, drill rows sown to either the perennial grass phalaris (Phalaris aquatica L.), perennial legume lucerne (alfalfa; Medicago sativa L.) or the annual legume subterranean clover (Trifolium subterraneum L.). Results showed that soil microbial abundance and diversity were related to plant distribution across the field at the time of sampling and to soil chemical parameters including total carbon (C), mineral nitrogen (N), pH, and available phosphorus (P), potassium (K) and sulfur (S). Despite the 27-month lag since sowing, pasture species remained concentrated around the original drill row with very little colonization of the inter-row area. The abundance and diversity of bacterial and fungal populations were consistently greater under drill rows associated with higher total C concentrations in the surface soil compared with the inter-row areas. Our results showed that the pH and available nutrients were similar between the subterranean clover drill row and the inter-row, suggesting that soil microbial populations were not impacted directly by these soil fertility parameters, but rather were related to the presence or absence of plants. The abundance of bacteria and fungi were numerically lower under phalaris rows compared to rows sown to legumes. The richness and diversity of fungal populations were lowest between rows where lucerne was planted. Possible explanations for this observation include a lower C:N ratio of lucerne roots and/or a lack of fibrous roots at the soil surface compared to the other species, illustrating the influence of contrasting plant types on the soil microflora community. This study highlights the enduring legacy of the drill row on the spatial distribution of plants well into the pasture phase of a cropping rotation and discusses the opportunity to enhance the microbiome of cropping soils on a large scale during the pasture phase by increasing plant distribution across the landscape.

Biogas digesters convert waste matter into a natural gas-like fuel and a nutrient-rich digestate by-product. This digestate has the potential to be used as a soil amendment to benefit crop production with or without biochar, a purported nutrient sponge. In a greenhouse study of several crop species, the effects of digestate fertilization on crop growth, photosynthetic efficiency, vegetable production and chemical nutrient levels were tested. Results indicate that increasing potency of the applied digestate fosters higher growth and fruit production rates of several studied plants but to a lesser degree than a conventional fertilizer. More potent digestate application increases antioxidant capacity, total phenolics content and ascorbic acid levels in kale compared to the control chemical fertilizer test groups but has confounding results on legume nutrient levels. Additionally, the combined application of biochar and biogas digestate added to compost and used as potting media positively impacts crop germination. This work has relevance to agrarian communities that could benefit from recycling livestock and food waste into fuel and a renewable fertilizer.

Cover crops are widely used to increase the quantity of organic carbon (C) returned to the soil between cash crops. Roots play an important role in increasing soil organic carbon (SOC) levels, but the root traits that impact SOC likely vary widely among cover crop species and this variation has yet to be characterized. Recently, cover crop mixtures have expanded in popularity as a way to increase the diversity of cover crop benefits. We tested the quantity, quality and spatial distribution of roots in three monocultures and one mixture to increase our understanding of root trait variation among species, and how that variation impacts mixture design. Root cores were taken from in-row and between-row locations to a depth of 40 cm from cover crops planted after winter wheat during the 2016–2017 growing season. These samples were taken from a larger maize–soybean–winter wheat organic grain rotation experiment (2012–2018) located in central Pennsylvania, USA. Cover crop treatments included monocultures of triticale (X Triticosecale Wittmack cv. ‘Trical 815’), canola (Brassica napus L. cv. ‘Wichita’), crimson clover (Trifolium incarnatum L. cv. ‘Dixie’) and a five species mixture dominated by those three species. Additionally, cumulative carbon (C) inputs were assessed for the entire rotation to determine cover crop and cash crop root C contributions. Root biomass C vertical and horizontal distribution, root-to-shoot (R:S) ratio, and root carbon-to-nitrogen (C:N) ratio differed among cover crop treatments. Triticale produced more root biomass in the between-row space at all depth intervals compared to other cover crop treatments. The five species mixture had more total 0–5 cm and between-row 0–5 cm root biomass than crimson clover in spring 2017. Cover crop and cash crop roots increased cumulative C estimates by between 37% (crimson clover) and 46% (triticale) compared to shoot C alone. Cover crop root trait information can inform the belowground benefits from combining different species into cover crop mixtures. Crimson clover produced less root biomass, surface root biomass and between-row root biomass than other cover crop treatments. Therefore, combining crimson clover with grass and certain brassica species can improve total root biomass production, and root distribution compared to crimson clover monocultures, whereas reducing the C:N ratio of roots compared to grass species monocultures. The five species mixture led to greater cumulative carbon inputs compared to monoculture treatments, which was due to greater cover crop biomass C and its influence on the following corn crop's biomass C.

An understanding of the nexus of organic fertilizer use decisions that smallholder farmers take is essential to designing relevant policy to support adoption in sub-Saharan Africa. In this paper, we applied exploratory factor analysis (EFA) on observed farmer decisions to identify a set of common management approaches that farmers in the northeastern part of Ghana adopt in using organic fertilizer. After identification, seemingly unrelated regression (SUR) analysis was applied to relate each approach to farmer characteristics that influence uptake decisions. The EFA identified four approaches, labeled as Augmentary Compost Use Approach, Urban Human Waste Organic Fertilizer Approach, Integrated Livestock Manure Approach and Mineral Fertilizer Cost Constraint Organic Approach. Each of the first three approaches involves a set of strategic farmer decisions which could be supported to increase organic fertilizer use. The SUR analysis showed that the uptake of each approach is affected by different subsets of farmer characteristics. However, participation in organic fertilizer management training positively influences the adoption of all four approaches. Thus, we recommend free training of smallholder farmers as a core element of any policy package to support organic fertilizer adoption.

The use of bio-based fertilizers derived from dairy manure can provide a valuable source of fertility, improve soil health and provide an outlet for manure from dairy operations. We conducted a small-scale discrete choice survey of crop farmers and crop consultants in Washington State to determine the attributes that were important to them in the potential use of a bio-based fertilizer product derived from dairy manure. Of the attributes examined, distribution channel was not statistically significant. Respondents preferred air-dried or pelletized forms to wet forms, though there was no statistically significant difference between air-dried and pelletized forms. As expected, uptake increased as price decreased. Our results imply that respondents would be willing to pay 23 and 39% more for an air-dried or pelletized product, respectively, than for a ‘semi-wet’ product. Our results indicate that there are other important attributes beyond the ones in the survey that led respondents to stay with their current fertilizer regime. Qualitative responses in the survey pointed to the need for field trial results and data on nitrogen release from the bio-based fertilizer. Greater understanding of willingness-to-pay and attributes important to potential end users is important for the development of markets for bio-based fertilizers.

The demand for water is high in the food industry, particularly during the processing of animal product origin. A more sustainable approach to the use of the water resource is needed to reduce its waste. A systematic literature review was carried out from publications identified according to relevance and timeliness. The aim was to find alternative food processing production methods that considered both recycling and reuse of water in different slaughtering of animals such as cattle, swine, poultry, goat, sheep and fish. Articles which addressed cleaner production methods were selected because of special relevance in water resource management, Poultry processing was considered a special case regarding the recycling and reuse of water. That was due to the volume of water used as well as the level of likely contamination it might pose if reused. Wastewater can be largely reduced by adopting changes in practices, such as plant layout; materials used; drainage systems using dedicated separation of effluents and shaded area at reception with ventilation and sprinkles.