The integration of vertical bifacial photovoltaic (PV) modules in agrivoltaics (AV) systems presents a novel opportunity to optimize land use by co-locating energy and food production. Vertical racking systems hold bifacial panels upright and stationary so that they can absorb sunlight from both sides while eliminating the need for sun-tracking mechanisms and large land footprints. This study evaluated the impact of vertically installed bifacial PV panels on the growth and productivity of silage corn during the 2024 growing season. Corn was planted between north-south oriented PV panel rows, with the following treatments: center, east (morning light/afternoon shade), west (morning shade/afternoon light), and an unshaded control with three replicates. Results showed no significant differences in silage or grain yields across treatments (p > 0.05), indicating this vertical PV system did not negatively impact crop productivity. However, significant differences in instantaneous net photosynthetic rate (Pn) and photosynthetically active radiation (PAR) were observed (p < 0.05), with the solar-east treatment exhibiting the highest Pn and PAR levels in the morning. These results support the viability of vertically mounted bifacial PV systems on a shade-sensitive crop. Furthermore, such systems can sustain corn productivity while accomodating energy infrastructure.

Growing pressure on food production, water resources, and renewable energy deployment has increased the need for integrated land-use strategies. Agrivoltaic systems (AVS), which co-locate solar photovoltaic (PV) installations with agricultural production, have emerged as a promising solution to improve land-use efficiency and climate resilience. However, existing modelling approaches are limited in their ability to represent the three-dimensional interactions governing food and water dynamics within AVS environments. This study developed a field-scale model (AVS-FW) using an integrated framework to represent the key factors affecting food and water dynamics in AVS in three-dimensional space. The AVS-FW used the framework to integrate the AVS-Microclimate model (simulating three-dimensional microclimatic conditions under solar panels), R-SWMS model (simulating three-dimensional soil condition and water transport), and Soil and Water Assessment Tool (SWAT) crop growth module (simulating plant growth). The AVS-FW model was demonstrated on a site in Colorado, USA, through scenario-based simulations comparing conditions with and without solar PV panels. The average actual evapotranspiration, water stored at the root depth, and biomass of lettuce with solar panels compared to without solar panels changed by −2.43% to −26.28%, 0.80% to 10.63%, and −3.17% to −34.63%, respectively. The temporal patterns of cumulative fluxes across soil domain boundaries were similar for cases with/without solar panels, but their magnitudes varied; and these were also found for total water volume in soil domain. The framework of the AVS-FW can assist decision-makers in evaluating the impacts of varied layouts (azimuth angles, inclinations, spacing, heights) and dimensions (lengths/widths) of solar PV panels on food and water dynamics in AVS.

Agrivoltaic systems, which co-locate solar photovoltaic systems and croplands, can potentially optimize land use. However, current models cannot represent all key factors regarding solar radiation and water depth on the ground surface under solar panels. This study developed a field-scale model, AVS-Microclimate, that can represent the key factors focusing on redistributions of solar radiation, precipitation (rainfall and snowfall), melted snow (snow on panel and ground), and solar panel cleaning water on the ground surface under solar panels in agrivoltaic systems. The AVS-Microclimate model was demonstrated through three-dimensional simulations of an agrivoltaic site in Colorado, USA. The precipitation, melted snow, and solar panel cleaning water redistribution module were parameterized using observed data, which showed a strong alignment for water distribution (percent bias: -1.64%, coefficient of determination: 0.95, and Nash-Sutcliffe efficiency: 0.95). The redistribution of solar radiation and water depth (precipitation, melted snow, and solar panel cleaning water) on the ground grids varied greatly for different weather conditions, grids, and/or times (dates and times of a day). The AVS-Microclimate can assist decision-making by assessing how layouts (inclinations, azimuth angles, heights, spacing) and sizes (lengths/widths) of solar photovoltaic panels affect solar radiation and water depth under solar panels, which are critical for crop production in agrivoltaic systems.

Semi-transparent cadmium telluride (ST-CdTe) photovoltaic (PV) technology is based on the use of CdTe in a thin film (2-8µm) to absorb and convert sunlight into electricity. The thin film is deposited onto clear glass and can be custom abraded to produce ST-CdTe PV modules of a desired transparency level (e.g. 50% full sun/50% transparency) making it an intriguing option for agrivoltaics (AV) applications. Recent improvements in ST-CdTe PV technology have matched the efficiency of crystalline silicon (c-Si) PV with the levelized cost of energy production far lower than conventional gas, coal, and nuclear generation [1]. A field experiment was conducted whereby ST-CdTe PV modules of two transparency levels (20% and 50%) and a full sun control (100% transparency) were temporarily installed in a RCBD with three replicates over winter wheat (Triticum aestivum L.) plants after anthesis and until harvest. The average net photosynthetic rate (Pn) of the full sun control was significantly higher than the 20% ST-CdTe PV module, but not different from the 50% transparency module. Measured factors for yield and protein content were statistically insignificant, except for wheat head number, which was significantly higher under 50% ST-CdTe PV than both the 20% ST-CdTe and full sun control. These results provide evidence that ST-CdTe PV module technology can provide renewable energy while balancing wheat yield potential and grain quality. The ability to adjust the transparency levels of the modules make ST-CdTe another PV technology option to consider for AV applications.

Background/Objectives: Microgreens are rich in nutrients and phytochemicals that can support healthy aging, including attenuation of cardiovascular disease risk. The nutrient and phytochemical contents of red beet (i.e., bull’s blood’ beet, Beta vulgaris) and red cabbage (Brassica oleracea var capitate) microgreens, as well as existing preclinical evidence suggest their cardioprotective effects, but the feasibility, gastrointestinal tolerability, and human health effects of daily microgreen consumption are unknown. This study aimed to evaluate the feasibility and gastrointestinal tolerability of 2 weeks of daily microgreen consumption in healthy middle-aged/older (MA/O) adults. A secondary aim was to characterize potential health effects. Methods: Healthy MA/O adults (initial n = 26) were randomized to consume either 2 cups of ‘bull’s blood’ beet or red cabbage microgreens daily for 2 weeks in a crossover design, with each treatment period separated by 2 weeks. Feasibility was determined through participant retention and intervention compliance (i.e., total doses consumed divided by 14 days), while gastrointestinal tolerability was determined by a gastrointestinal health questionnaire and bowel movement log. Impacts of microgreen consumption on brachial and aortic hemodynamic parameters, and gut microbiota composition were evaluated. Results: Daily consumption for 2 weeks of ‘bull’s blood’ beet and red cabbage microgreens was found to be feasible as indicated by high participant retention (final n = 24) and overall treatment compliance of 95.6%. Gastrointestinal symptom severity was not impacted overall, though an improvement in gastrointestinal inflammation-associated symptom severity scores following the red cabbage microgreen intervention (p = 0.047) was observed. There were no changes in bowel movement quality, hemodynamic parameters, or on alpha or beta diversity of the gut microbiota. Conclusions: Daily consumption of ‘bull’s blood’ beet and red cabbage microgreens is feasible and tolerable in healthy MA/O adults. Future studies designed to evaluate their health impacts are needed.

Pantoea agglomerans is one of four Pantoea species reported in the USA to cause bacterial rot of onion bulbs. However, not all P. agglomerans strains are pathogenic to onion. We characterized onion-associated strains of P. agglomerans to elucidate the genetic and genomic signatures of onion-pathogenic P. agglomerans. We collected >300 P. agglomerans strains associated with symptomatic onion plants and bulbs from public culture collections, research laboratories, and a multi-year survey in 11 states in the USA. Combining the 87 genome assemblies with 100 high-quality, public P. agglomerans genome assemblies we identified two well-supported P. agglomerans phylogroups. Strains causing severe symptoms on onion were only identified in Phylogroup II and encoded the HiVir pantaphos biosynthetic cluster, supporting the role of HiVir as a pathogenicity factor. The P. agglomerans HiVir cluster was encoded in two distinct plasmid contexts: (i) as an accessory gene cluster on a conserved P. agglomerans plasmid (pAggl), or (ii) on a mosaic cluster of plasmids common among onion strains (pOnion). Analysis of closed genomes revealed that the pOnion plasmids harbored alt genes conferring tolerance to Allium thiosulfinate defensive chemistry and many harbored cop genes conferring resistance to copper. We demonstrated that the pOnion plasmid pCB1C can act as a natively mobilizable pathogenicity plasmid that transforms P. agglomerans Phylogroup I strains, including environmental strains, into virulent pathogens of onion. This work indicates a central role for plasmids and plasmid ecology in mediating P. agglomerans interactions with onion plants, with potential implications for onion bacterial disease management.

There are many benefits to producing insects for food and feed; they require fewer resources to produce, process, and distribute. The digested and undigested waste along with insect feces (i.e., frass) from the mass production of insects can be considerable. Black soldier fly larvae (BSFL) digestion of organic residue produces frass that is high in macronutrients that are desirable for plants, potentially serving as a partial replacement for fertilizer or growing media, such as peat. Arugula and lettuce were grown in greenhouse pot studies with treatments comprised of BSFL frass (BSF), vermicompost (VC), and peat, and compared to a 100% peat control (CP). Yield, productivity, greenness, and tissue nutrient concentrations were measured. Arugula and lettuce produced the highest fresh weight and dry weight in the BSFL treatments. Primary macronutrients (N, P, K) and Mg in both crops were also highest in the BSFL treatments. Secondary macronutrients (Ca, Mg, S) and micronutrients produced more variable results (B, Fe, Mn, Cu, Zn). Lettuce produced larger yields but had much lower concentrations of nutrients compared to arugula. In small amounts, 10–20%, BSFL frass can serve as a good replacement for peat in leafy green crops. It is an especially beneficial way to recycle organic side streams in different industries and reduce waste production overall.

The United States has experienced an abrupt increase in commercial industrial hemp production following the Agricultural Improvement Act of 2018. However, the historical prohibition has resulted in a lack of basic research on the physiology of this crop and its response to stresses such as those produced by local climatic conditions and pests that feed on hemp, which are needed to guide development of effective management practices. For example, abiotic stress can stimulate plants to increase production of secondary metabolites such as phytocannabinoids. This is of particularly high importance to growers of hemp crops that are oriented to the production of phytocannabinoids concentrated in flowers, balancing optimization of CBD yield (crop value) with regulatory requirements (total THC < 0.3% by mass) that could lead to mandated destruction. In this study we evaluated the impact of defoliation stress (to simulate hail damage) at three different growth stages. Our results indicate that defoliation stress during vegetative and late flowering yielded no significant change in total % phytocannabinoid concentration at harvest. However, defoliation stress during early flowering yielded a significant increase in phytocannabinoids, including total % CBD and THC, at harvest as compared to untreated controls.

The present study summarizes two growing seasons (2020–2021) of microclimate characterization and vegetable crop growth in an agrivoltaics system in northern Colorado, USA. The replicated experiment evaluated three module transparency types (opaque silicon [0 % transparent], bifacial silicon [∼5 % transparent], and semi-transparent cadmium telluride [40 % transparent]) plus a full sun control, and four vegetable crop species (summer squash, peppers, tomatoes, and lettuce). Air temperature under the modules in July was approximately 0.5 °C cooler than in the full sun. Soil temperature (2.5 cm depth) maximum differences were more pronounced and were 5.8 °C, 9 °C, and 14.4 °C cooler under bifacial, semi-transparent, and opaque silicon, respectively. For summer squash growing directly under the solar modules, yield was significantly reduced under each of the module transparency types. However, there was no statistically significant yield reduction for peppers, tomatoes, and lettuce indicating their suitability in an agrivoltaics system. The numerical yield of most crops increased as the transparency of the solar modules increased, which could be the focus on future work.

Agrivoltaics (APV), the co-location of agriculture and photovoltaics (PV), addresses an inherent competition for land usage. Taking the same dual-use concept to the urban landscape, rooftop APV can provide locally grown food in areas of need while providing distributed energy generation. In this multi-year investigation, different APV plots in northern Colorado, USA, were studied for crop metrics, light transmission, air temperature, soil/substrate temperature and moisture. Crops were grown under different solar panel types including opaque silicon and opaque and semi-transparent (ST) thin-film CdTe technologies. Growth conditions were characterized showing generally improved conditions and moderated temperatures under the panels. The ST-CdTe panels had increased photosynthetically active radiation (PAR) compared to both opaque panel types without a significant corresponding increase in temperature.

The "insects as food and feed" movement is gaining considerable momentum as a novel means to provide protein to people (i.e., food) and other animals (i.e., feed). Insects require significantly fewer resources, such as water and land, to produce, process, and distribute as a food or feed source. While the production of insect biomass has received considerable attention for use as food or feed, little is known about the value of the residual materials remaining after digestion. One insect, the black soldier fly, Hermetia illucens (L.) (Diptera: Stratiomyidae), can generate large quantities of residual (i.e., frass) that is high in nitrogen, phosphorus, and potassium. These materials could serve as a partial replacement for fertilizer or peat, thus creating added value to the insects as food and feed sector. Greenhouse studies were designed to investigate the use of frass in vegetable production. In pot studies with tomatoes, different ratios of peat:vermicompost and peat:insect frass were compared to a 100% peat control. Across all other parameters, tomato fruits and vegetative biomass did not produce significant differences across treatments, indicating results were comparable to the control (i.e., 100% peat). Thus, replacing peat with black soldier fly frass is a viable option and could allow for the peat industry to become more sustainable and regenerative. However, it should be noted that average individual tomato fruit weight was significantly (P < 0.05) higher (by 19%) in the vermicompost 10% treatment compared to the control, which did not differ from treatments including black soldier fly frass.

Abstract Adoption of cover crops in arid agroecosystems has been slow due to concerns regarding limited water resources and possible soil moisture depletion. In irrigated organic systems, potential ecosystem services from cover crops also must be considered in light of the concerns for water conservation. A constructive balance could be achieved with fall-sown small grain cover crops; however, their impacts on irrigated organic systems are poorly understood. Our first objective was to determine the ability of fall-sown small grains [cereal rye (Secale cereale L), winter wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) and oat (Avena sativa L.)] to suppress winter weeds in an irrigated, organic transition field in the southwestern USA. Small grains were planted following the legume sesbania (Sesbania exaltata (Raf.) Rydb. ex A.W. Hill) during Fall 2012 and Fall 2013. In Spring 2013 and 2014, weed densities and biomass were determined within each cover crop treatment and compared against unplanted controls. Results indicated that both barley and oat were effective in suppressing winter weeds. Our second objective was to compare weed suppression and soil moisture levels among seven barley varieties developed in the western United States. Barley varieties (‘Arivat’, ‘Hayes Beardless’, ‘P919’, ‘Robust’, ‘UC603’, ‘UC937’, ‘Washford Beardless’) were fall-sown in replicated strip plots in Fall 2016. Weed densities were measured in Spring 2017 and volumetric soil moisture near the soil surface (5.1 cm depth) was measured at time intervals beginning in December 2016 and ending in March 2017. With the exception of ‘UC937’, barley varieties caused marked reductions in weed density in comparison with the unplanted control. Soil moisture content for the unplanted control was consistently lower than soil moisture contents for barley plots. Barley variety did not influence volumetric soil moisture. During the 2017–2018 growing season, we re-examined three barley varieties considered most amenable to the cropping system requirements (‘Robust’, ‘UC603’, ‘P919’), and these varieties were again found to support few weeds (≤ 5.0 weeds m−2). We conclude that several organically certified barley varieties could fill the need for a ‘non-thirsty’ cover crop that suppresses winter weeds in irrigated organic systems in the southwestern United States.

ABSTRACT Background Microgreens are the young leafy greens of many vegetables, herbs, grains, and flowers with potential to promote human health and sustainably diversify the global food system. For successful further integration into the global food system and evaluation of their health impacts, it is critical to elucidate and optimize their nutritional quality. Objectives We aimed to comprehensively evaluate the metabolite and mineral contents of 6 microgreen species, and the influence of maturity on their contents. Methods Plant species evaluated were from the Brassicaceae (arugula, broccoli, and red cabbage), Amaranthaceae (red beet and red amaranth), and Fabaceae (pea) plant families. Nontargeted metabolomics and ionomics analyses were performed to examine the metabolites and minerals, respectively, in each microgreen species and its mature counterpart. Results Nontargeted metabolomics analysis detected 3321 compounds, 1263 of which were annotated and included nutrients and bioactive compounds. Ionomics analysis detected and quantified 26 minerals including macrominerals, trace minerals, ultratrace minerals, and other metals. Principal component analysis indicated that microgreens have distinct metabolite and mineral profiles compared with one another and with their mature counterparts. Several compounds were higher (P < 0.05; fold change ≥2) in microgreens compared with their mature counterparts, whereas some were not different or lower. In many cases, compounds that were higher in microgreens compared with the mature counterpart were also unique to that microgreen species. Conclusions These data provide evidence for the nutritional quality of microgreens, and can inform future research and development aimed at characterizing and optimizing microgreen nutritional quality and health impacts.

demand for organic food in the United States continues to increase at two to three times the rate of demand for non-organic food and a substantial portion of this is organic fruits and vegetables. A comprehensive breeding and seeds system targeted to organic production systems is required to provide the cultivars needed to support increasing demand for fruits and vegetables. Farmers still lack access to a wide array of certified-organic seed and vegetable varieties adapted to organic production. Cultivars that are best adapted to organic production will be those bred under organic conditions. The Northern Organic Vegetable Improvement Collaborative (NOVIC) was implemented to increase the diversity and choice of vegetable cultivars available to organic farmers. It has been funded in three four-year cycles with the project currently in its second year of the third cycle. It is a collaboration of six institutions and over 30 organic farms in six states. The overall goal of NOVIC is to increase the proportion of U.S. agriculture that is managed organically. NOVIC uses participatory plant breeding and participatory variety trialing to understand farmers’ needs and conduct breeding efforts. The project has three major initiatives: 1) to conduct vegetable variety trials to identify those adapted to organic systems; 2) to breed vegetable crops where needs are identified; and 3) to provide farmers with the knowledge to produce their own seed and to breed their own varieties. NOVIC has been instrumental in 10 releases of four crops, with another 12 varieties of seven crops in the pipeline. In addition, there are numerous private sector varieties that have undergone evaluation in NOVIC trials. Essentially all of farmers who have participated in NOVIC have indicated that they have changed varieties based on regional trial results. Outreach activities have occurred in about a dozen states through plant breeding workshops and videos and publications are available online.

The production of insect protein as human food and livestock feed (entomophagy) may provide a more environmentally beneficial alternative to traditional animal agriculture. However, the resulting waste product from insect production has resulted in large accumulations of left-over substrate and frass. Due to its nutrient and microbial profile, this left-over product has the potential to be utilised as a biofertiliser for high value crop production. Studies have been conducted using the frass of various insects (e.g. black soldier flies, houseflies, and mealworms) to monitor its impact on crop productivity. Overall, frass tends to have similar or better results when compared to inorganic fertilisers, especially when combined with them. Aside from productivity and growth, frass may also preserve soil fertility by decreasing leaching and infiltration, and reducing the prevalence of disease and pathogens. In addition, chitin found in frass also has beneficial properties for plant/crop growth and disease resistance. Monitoring the dietary inputs of industrially reared insects may be the best way of mitigating the potential negative impacts of frass application, such as increased electrical conductivity and heavy metal toxicity. No single study confirms all of these benefits at once. Future studies should focus building onto these results by demonstrating systems levels benefits.

Stip is a physiological disorder that affects certain pepper (Capsicum annuum) cultivars, most notably bell-pod types. It has been attributed in the literature to nutrient imbalances, temperature extremes, and/or other environmental stressors. Symptoms present as brown, black, and yellow ovoid-shaped necrotic lesions ≈0.5 to 1.2 cm long by 0.5 cm wide. Between 2014 and 2015, symptomatic and asymptomatic pods were harvested from 15 commercial farms in southern New Mexico. Fluorescent microscopy comparisons of harvested symptomatic tissue revealed a unique fluorescent signature and the absence of chlorophyll. A new spectral peak centered around 560 nm was observed in symptomatic tissue. High-performance liquid chromatography (HPLC) and gas chromatography–mass spectrometry (GC-MS) analyses of these tissues detected significant differences in 13 metabolites, of which several have been associated with fruit maturation and/or senescence. This report represents the first combination of a detailed microscopic description and metabolite profile of field-grown symptomatic plants with this disorder.