ASHS 2024 Conference

Assessing Producers’ Interest and Barriers in the Transition to Organic Principles - Brenton Breland
Merging Traditional Ecological Knowledge with Modern Organic Practices: A Case Study in Participatory Research - Erin Silva
Growing Urban Organic Farms in Iowa: New Initiatives and Support - Kathleen Delate
Bridging the Gap: Culinary Breeding Network Facilitates Collaboration in Variety Development - Lane Selman
Metabolomic Analysis Provides Novel Insight Into the Evaluation of Organic Tomato Fruits - Jashanpreet Kaur

In the changing landscape of horticulture, sustainability and organic practices have taken center stage. As of the 2021 USDA Organic Certified Survey, 17,445 certified organic farms representing 4,895,279 acres operated in the United States. Our research aims to understand the motivations and barriers that producers encounter when transitioning from conventional to organic production. Mississippi State University partnered with the University of Nebraska – Lincoln as part of the USDA AMS Transition to Organic Partnership Program (TOPP) whose focus is on supporting mentorships, helping overcome barriers, and educating producers. Following a TOPP-sponsored workshop in November 2023, it was noted that both beginning and experienced farmers were very interested in the process of transitioning to organic production. Participants noted their decision to transition was “very much influenced” by economics, market demand, environmental concern, health, and ethics. A review of literature revealed that, while there is a significant body of research on sustainable practices, there remains a gap in understanding the challenges that producers face. To bridge this gap and address the key findings from our workshop, a 43-question national survey was developed. It addressed motivations and barriers while also gathering demographic data to contextualize responses. Producers were questioned about cover crops, crop rotation, no-till farming, and composting among other practices. Social, environmental, and technical concerns were also addressed. Responses included motivations driven by environmental consciousness as it relates to soil health, reduced synthetic chemical inputs, and the goal of improving and maintaining biodiversity on their farms reiterating our previous findings. Producers indicated that they are encouraged by the amount of information available concerning organic production practices; however, they noted a knowledge-implementation gap. Financial constraints and space limitations were also concerns. The survey functions as the inception point for a case study following a beginning farmer in Calhoun City, Mississippi as they adopt organic principles in a region where the use of these growing practices is less than common. The insights gathered from the workshop, national survey, and case study will guide the understanding of producers’ motivations and will serve to inform policymakers, extension services, and the horticulture community at large. This ongoing project and its explorations are not only timely but also critical in shaping a future where horticulture aligns with the ethos of conservation and social equity.

Research in plant ecology and sustainable farming advocate for increasing crop diversity on farms over monocultures. Crop diversity provides many ecosystem services, but mainstream farming relies heavily on mechanical and chemical solutions known to degrade land quality to ensure optimal yields. For centuries, Indigenous peoples in North America maintained sustainable cropping systems characterized by crop diversity and minimal inputs, such as the Three Sisters system. To integrate this knowledge into current research, we collaborated with Indigenous corn growers in Wisconsin interested in growing their traditional corn varieties with cover crops seeded between the rows. Growers are interested in knowing which cover crop mixtures synergize well with their corns while suppressing aggressive weeds. Single and mixed plantings of winter wheat, clover, and chicory/plantain were sown after corn planting while establishing a hand-weeded and weedy control. From 2021 to 2023, we found the triple mixture to lower weed biomass at the end of the season while also having the highest total relative yield, indicating cover crops in this mixture accumulated more biomass than their single plantings. No corn yield was collected in 2022, but low nutrients impacted corn yield in 2021, which was lower overall compared to the 2023 corn yield. Within 2021, weed pressure played a significant role in reducing corn yield, but the single planting of clover and winter wheat had higher yields than the control left weedy and comparable to the control with no cover crops or weeds. In 2023 all cover crop treatments and controls did not differ significantly indicating these corn varieties have a potential higher tolerance from weed or cover crop competition. Indigenous growers now have data relevant to their corn varieties and their goals to preserve their traditional food systems. The trial and error from these experiments was integral to the relationship building between UW-Madison and our Indigenous partners, creating a shared learning environment to better understand sustainable farming practices. From this project, we have developed a framework to guide agricultural research with Indigenous communities centered on the principles of traditional Indigenous farming.

In the past decade, there has been a significant rise in initiatives by public sector programs, independent seed companies, and farmer-breeders aimed at developing organic varieties in the United States, particularly targeting farmers engaged in direct-to-consumer sales. Flavor has emerged as a paramount trait for these farmers, driving collaborative breeding efforts involving a diverse array of stakeholders, including farmers selling to restaurants, farmers markets, and CSAs, as well as chefs at farm-to-table establishments, and plant breeders focusing on organic systems. Since seed regulations in the US allow seed to be sold without a registration process, varieties identified as well-suited and high-quality by collaborating farmers and chefs can quickly become available commercially. While diversified organic vegetable farmers often prefer not to produce their own seed, they wish to be actively engaged in the selection processes and support plant breeders focusing on organic systems (Hubbard and Zystro, 2016). The Culinary Breeding Network (CBN) strives to bridge the gap between plant breeders and consumers by facilitating unique opportunities for stakeholders to assess in-development vegetable and grain cultivars, share insights, and actively contribute to variety development. CBN's outreach events span across various regions, including Oregon, Washington, Hawaii, Wisconsin, New York, and Italy, focusing on identifying desirable traits, discerning consumer preferences, tailoring varieties to organic farms and palates, and celebrating local foods. These participatory public gatherings provide breeders with invaluable input rarely accessible otherwise. By integrating culinary professionals, farmers, and consumers into the breeding process, breeders gain deeper insights into preferred traits while also fostering broader awareness and understanding of organic plant breeding. CBN impact is evaluated through post-event surveys completed by attending farmers, chefs, distributors, retailers, and consumers. In 2020, 144 Variety Showcase surveys were collected, with 96% expressing intentions to disseminate gained knowledge, reaching an estimated >2,075 individuals in person and >258,000 through social media. Furthermore, 81% indicated that newfound knowledge would influence their work through expanded networks (34%), revised buying practices (25%), and informed decision-making (41%), among other outcomes such as forging new collaborations and partnerships. Participating breeders, seed companies, and farmers report moderate to significant positive effects to CBN, with 75% reporting impact on their business operations. Notably, CBN's most valued impact lies in "creating buzz in the community around specific vegetables and varieties" (48%) and "facilitating collaboration among breeders, growers, chefs, and consumers" (35%). Remarkably, 80% of respondents stated they had commenced growing a variety following a CBN event.

Urban agriculture, which encompasses both home use and commercial sales, has shown positive impacts on enhancing sustainable agriculture and food security, especially for disadvantaged and underrepresented citizens. The benefits of community gardens/farms have been found to be extensive, including improved quality of life and nutrition, enhanced economic security and environmental sustainability, entrepreneurship and employment, and community commitment. In a new Iowa State University (ISU) Extension and Outreach project, the ISU Organic Ag program (OAP) will be working with urban farms in Iowa to create a Community of Practice network that will promulgate best management practices and sharing of results among farmers and agency staff supporting this clientele group. Because the majority of urban farms use organic practices, these farms will be surveyed for critical pest issues; suitability of organic treatments for specific pests; and economic viability of these strategies. In addition, farmers will be queried on the potential for organic certification, including group certification. A statewide Urban Ag group, created in 2023, identified the following needs, based on urban farmers’ interests: Land access and utilization; Education and program access; Production needs, including managing soil health and irrigation; Food safety and food insecurity; and Business development. A Directory of Expertise in Urban Ag was developed to highlight six specialists focused on urban ag in Iowa at Iowa State University; four at federal agencies (NRCS, RMA, FSA), three in state and municipal government (IDALS, City of Des Moines); two at government-associated programs (SWCD), and eight at non-profit, non-governmental institutions (NGOs). Working with county Extension staff, Master Gardeners, 4-H, NRCS, SWCD, and urban ag NGOs and farmers, this project seeks to advance Urban Ag through: 1) Demonstration sites showcasing innovative nutrient and pest management techniques, bee keeping, food safety practices, and marketing; 2) Field Days held at key urban farm partners with adjoining Farmers’ Market tours; and 3) A series of webinars, videos and pamphlets covering these topics, and translated for Spanish, Burmese and Congolese audiences–the most prominent groups of immigrant urban farmers in Iowa. Evaluation will assess knowledge and behavioral change related to addressing key food security concerns in urban spaces, community well-being, and sustainability indicators, including soil and water quality.

A gradual shift in the evaluation of crop quality has taken place, led by analytical scientists with the advancement of instrumentation and system-based technology (system biology). Metabolomics, one of the emerging omics techniques, provides a complete and unbiased chemical analysis within an organism. Information obtained through metabolomic analysis may range from identifying beneficial compounds for human health to toxicants, can help solve challenges faced by the agricultural industry. Current phytochemical studies focusing on organically-grown crops have typically focused on individual compounds or classes of compounds that may be affected by production practices. This study compared metabolomic profiles between organic and conventionally-grown tomato (Solanum lycopersicon) fruit to systemically access the quality and nutritional value of tomatoes under different growing conditions. Two tomato cultivars (‘Estiva’ and ‘Tomimaru Muchoo’) were grown with three different treatments (organic field, organic high-tunnel, and conventional field) and were assessed for metabolomic analysis using gas chromatography‒mass spectrometry (GC‒MS) and liquid chromatography‒mass spectrometry (LC‒MS). Target metabolites included various primary and secondary metabolites covering a wide range of metabolic pathways, involving citrate cycle, pyruvate metabolism, amino acid biosynthesis, alkaloids biosynthesis, shikimate pathway, salicylic acid pathway, plant hormone biosynthesis, phenylpropanoid biosynthesis, flavone, flavonol, and flavonoid biosynthesis, anthocyanin biosynthesis, and so on. Differentially expressed metabolites (potential biomarkers) between organic and conventional tomatoes were selected, and a core metabolic network was identified by pathway enrichment analysis. Major variations between groups were observed in the network related to plant secondary metabolisms (e.g., plant defense signaling). This is likely due to varying amounts of external stresses between organic and conventional tomatoes by the difference in pesticide input. The organic high-tunnel group also showed some distinct metabolic responses within the secondary metabolisms, probably because of its unique growing conditions. The selected biomarkers and identified metabolic network provided insights into biochemical processes influenced by different cultivation methods. This work will contribute to the evaluation of organic farming practices in the US.

Discussion on the regional activities of USDA-AMS Transition to Organic Partnership Program (TOPP)

Phenotypic landscape of the photosynthetic performance and seed productivity of spinach germplasm under organic conditions - Vijay Joshi
The Southern Cover Crop Variety Trial Program - Assessing Regional Adaptation of Cover Crop Varieties Across the Southern US (Year 2) - Virginia Sykes
Production of short, medium and long season specialty crops in high-residue, no-till farming systems - Arianna Bozzolo
Comparison of Plastic Mulch and Cover Crops - Roller Crimper Systems on Weed Pressure Soil Moisture and Yield in Organic Strawberry Production - Arianna Bozzolo
Impacts of Organic Soil Amendments on Hemp Production - Arnab Bhowmik
Biomass Source of Biochar and Genetic Background of Tomato Influence Plant Growth and Development and Fruit Quality - Rishikesh Ghogare
Nitrogen Utilization from Compost in Organic Strawberries - Mark Kindred
Interactions between photoselective plastics and insect pest dynamics in an organic brassica vegetable system -Dilip Nandwani
Anaerobic Soil Disinfestation: A Non-chemical Approach to Managing Weeds and Nematodes in Sweetpotato - Simardeep Singh
Potential Establishment of Entomopathogenic Fungi as an Endophyte in Citrus Trees Over Time - Joseph Paoli
Impact of Biosolid Compost - Madeleine Tenny

Identifying suitable genetics for low-input organic spinach production and ensuring an adequate supply of organic seeds are critical challenges for organic spinach breeders. This study comprehensively assessed 300 spinach accessions sourced from the USDA National Germplasm Repository and commercial checks. The field trials were conducted at Uvalde, TX, during the 2022-23 and 2023-24 growing seasons, focusing on biomass and nitrogen use efficiency. During the 2023-24 field trial, natural variations in leaf photosynthetic performance, including carbon assimilation, stomatal conductance, photosynthetic electron transport rate (ETR), and PSII actual photochemical quantum yield (PhiPS2), were analyzed utilizing an LI-6800 gas analyzer. The seed productivity traits, such as yield per plant and 100-seed weight, were evaluated at the Organic Seed Alliance Washington field site. The processed data were employed for Genome-Wide Association Analysis (GWAS) to identify underlying genetics associated with organic productivity and photosynthetic traits. Over 88k Single Nucleotide Polymorphisms (SNPs) dispersed across six chromosomes were utilized in the GWAS after stringent filtering criteria. Significantly associated SNPs and candidate genes were delineated for the targeted photosynthetic traits and seed productivity, shedding light on potential genetic factors influencing these crucial traits in organic spinach breeding programs.

Cover crops provide numerous ecological benefits to production systems. Maximizing these benefits requires identifying species and varieties that are the best fit both geographically and for the planting/termination time frame dictated by the accompanying cash crop system. In 2019, the University of Tennessee began a cover crop variety trial to help growers make better informed decisions on which of a broad range of cover crop species and varieties worked best in their specific region and production system. In fall 2022, in collaboration with the Southern Cover Crops Council, this trial was expanded to cover a 10-state region of the Southern US (TN, FL, NC, KY, VA, SC, TX, GA, AR, and AL) and became known as the Southern Cover Crop Variety Trial. This trial program is currently in its second year, with each trial year running from fall through the following spring. Trial sites were planted in mid-October each year. Cover crop cover, weed suppression, height, biomass, and estimated nitrogen release were measured in early and late spring. Twenty entries each were evaluated in the 22-23 and 23-24 trial years. However, as a fee-based program, entries were submitted by public and private institutions and varied from year to year. Eleven of the twenty entries were evaluated in both trial years. In year one, top-performers by rank were largely uniform across sites, consisting primarily of cereal rye and hairy vetch varieties. Many clover species, particularly crimson clover, exhibited greater variation in performance ranking among locations. Performance values varied significantly among and within locations, species, and evaluation period. Data collection for year two will be completed in Spring 2023 and will be presented.

When speaking to diversified vegetable crop growers, one of the most often cited challenges is the management of weeds. This issue is even more prevalent for organic growers who lack any effective chemical weed control method and rely on crews to mechanically remove weeds from the fields. One possible alternative is the use of terminated cover crops as mulch on the soil surface to act as a physical barrier to prevent weed emergence. This cover crop mulch can be advantageous for a grower in addition to cover crops improving soil health and providing a habitat for beneficial insects. This experiment compared vegetable beds with cover crops terminated with a roller crimper to bare soil beds on short (squash), intermediate (pepper), and long (eggplant) growing vegetable crops and assessed crop performance. In both 2023 and 2024 a cover crop mix of rye and field peas was successfully terminated and provided ample biomass on the soil surface at the time of vegetable transplanting and throughout their grower and harvest. We found that cover cropped treatments led to improvements in soil fertility, higher numbers of soil-dwelling beneficial insects, and lower weed pressure that led to significantly higher yields. These results demonstrate a potential system for organic growers to integrate into their operation as a practice that can reduce time and labor costs for weed management along with improving the soil fertility and creating a system requiring fewer inputs.

While organic production of specialty crops has been highly successful in southern California, it relies heavily on the use of plastic mulch and intensive tillage for weed management. A two-year study conducted from 2022 to 2023 aimed to evaluate the impact of plastic mulch and a cover crop based reduced tillage system using a -roller crimper to terminate cover crops on weed pressure and yield in organic strawberry production. Bare root strawberry crowns of the Albion variety were transplanted into four treatments: 1) Sorghum-sudangrass (S. bicolor x S. sudanense) seeded at 100 kg/ha (Sorghum 1), 2) Sorghum-sudangrass seeded at 200 kg/ha (Sorghum 2), 3) buckwheat seeded at 67 kg/ha, or 4) plastic mulch as standard practice. Cover crops were broadcasted on 1.5 m wide raised beds in May and terminated with a roller crimper in August. Both seeding rates of Sorghum-sudangrass effectively suppressed weed growth before and after termination compared to buckwheat. The significantly lower biomass of buckwheat after termination, relative to the Sorghum-sudangrass treatments, indicates variations in weed suppression efficacy among cover crops. Total differences in soil moisture, calculated based on data collected weekly from after cover crop termination to end of harvest, indicate that all treatments resulted in lower soil moisture levels compared to the plastic control, with the buckwheat treatment showing the most significant decrease. At harvest there were no significant differences between plastic mulch and Sorghum-sudangrass 1 and 2 treatments, indicating comparable yields. Buckwheat resulted in the lowest yield, experiencing a 50% reduction compared to plastic mulch. Based on the findings, plastic mulch and Sorghum-sudangrass planted at different seeding rates can be considered effective alternatives for weed suppression and maintaining yields comparable to conventional plastic mulching. The choice between Sorghum-sudangrass seeding rates may depend on factors such as cost, availability, and specific field conditions. The reduced biomass production of buckwheat compared to Sorghum-sudangrass, coupled with its rapid decomposition rate, resulted in diminished efficacy of buckwheat in weed suppression. Consequently, reduced weed control was observed, leading to significantly lower yields in buckwheat-treated plots compared to Sorghum-sudangrass and control treatments. These findings suggest that buckwheat may not be a viable option for organic strawberry production under comparable conditions, emphasizing the importance of selecting cover crops with longer-lasting weed-suppressive qualities.

Hemp (Cannabis sativa L.) is a highly versatile crop that has attracted considerable attention among farmers due to its diverse applications. Recent studies have sought to establish a fundamental understanding and baseline of the nutritional requirements of hemp, opening up possibilities for organic hemp production. Our research focuses specifically on evaluating the productivity of a floral hemp variety using different regenerative practices, with a particular emphasis on organic soil amendments that promote soil health in Piedmont area of North Carolina. The field experiment was conducted at North Carolina A

The evolving effects of climate change and intensive agricultural practices have adversely affected soil health and crop yields. This necessitates the need to maintain and improve soil health for sustainable food production. Biochar, a carbon-rich material produced from pyrolysis of biomass is being considered as a novel soil amendment that can potentially restore soil health and improve crop yields. Several studies have reported both positive and negative effects of biochar on crop yields while focusing mainly on one type of biochar and a single plant cultivar. However, the effects of different types of biochar and its interaction with plants with different genetic backgrounds has remained unexplored. In this study, we evaluated the impact of six different biochars on the growth performance and fruit quality of three tomato (Solanum lycopersicum) cultivars. The hypotheses that (1) biochars derived from different feedstock sources would produce unique phenotypes in a single cultivar of tomato, and (2) single feedstock-derived biochar would produce different phenotypes in each of the three tomato cultivars were supported by obtained results. This study demonstrated that plant genetic background and biomass source are important variables to consider for using biochar as a soil amendment.

Strawberries are typically grown in high tunnels in the Intermountain West region to protect the flowers and buds from early and late-season frosts and extend the growing season. Organic farmers rely on N mineralization from organic sources to supply plant-available N which can be inadequate for plant needs, especially when temperatures are low. To support cultivar selection for organic strawberry production in high tunnels, greenhouse cultivar trials were conducted to determine if some strawberries grow better on compost than others. Plants were grown for six weeks in a mixture of turface and peat moss with and without compost. A complete liquid fertilizer with and without added N was supplied daily. Leaf, crown, and root dry weights, tissue, and compost N at the beginning and end of each trial were measured and leachate was collected daily and analyzed for nitrate and ammonium. Plant chlorophyll was determined at the end of the experiment. Plants that received liquid N fertilizer grew more, absorbed more N, and had a higher chlorophyll reading compared to plants that received the compost and N-free fertilizer treatment. Ammonium was leached out of the compost-treated pots in the first two weeks while little nitrate was lost. Some cultivars performed better than others on the compost treatment. This suggests that some strawberry cultivars are better able to grow on organic nitrogen sources than others but, additional N fertilization may be needed.

Brassica crops are susceptible to a variety of insect pests of particular significance in organic production systems, including flea beetles, aphids, and lepidopteran caterpillar pests. These pests are abundant on brassicaceous vegetable crops throughout the U.S. and populations frequently are high enough to significantly reduce crop quality. There is an increased interest among small and mid-size vegetable growers to adopt poly-covered tunnels to protect high value horticultural crops. Tunnel production allows for season extension, can protect crops from adverse weather conditions, improve the quality of horticultural crops, and may also influence plant-insect dynamics. Photoselective poly coverings influence light wavelength and transmission in tunnel environments and may affect plant physiological responses as well as incidence of disease and herbivory by insect pests. Here, we explored the impact of UV light blocking and UV light transmitting poly coverings on Lacinato kale (Brassica oleracea var. acephala) production and the effects on pest and beneficial insect populations in a tunnel environment compared to an open field system on certified organic land in Morris, MN. Our results showed that total kale harvestable yield was similar between the poly covered tunnels and open field plot treatments. No differences in yield or insect pest pressure were observed between UV light blocking or transmitting poly covered tunnels but were observed between tunnels and the open field environment. Imported cabbageworm populations were 75% higher in tunnels versus open field plots (P=.0023), however the inverse was observed for cabbage loopers, which were 60% higher in open field plots (P=.0072). No flea beetles were found in tunnels, and an average of 1 beetle/plant was observed in open field plots. Diamond back moth and aphid populations were not different between the tunnel and the open field plots. Overall, insect pest populations did not reach economically damaging thresholds during the study period, likely due to the field plot location which did not have a history of brassica production. Our results showed that light transmission and ambient air temperatures were similar under the photoselective poly coverings. We observed that pest pressure increases rapidly in tunnel environments as the season progressed regardless of poly covering. Although our study did not observe differences in the yield or quality of kale across production systems, there were differences in insect pest populations across systems, indicating a different management approach may be needed to prevent crop damage in tunnel environments.

Anaerobic soil disinfestation (ASD) is a promising organic pest management strategy and is an alternative to chemical-led approaches that has shown potential to manage weeds and soil-borne pathogens in organic vegetable production systems. ASD is facilitated by incorporating carbon sources into the soil, tarping the soil with plastic mulch, and irrigating to the soil saturation point. To evaluate the impact of ASD on weed and nematode management in organic-grown sweetpotato, greenhouse studies were conducted at Clemson University, Clemson, South Carolina. Experiments were laid out in a randomized complete block design in 2-gallon microcosms with two carbon sources [ASD (soil amended with chicken manure molasses as carbon source) and non-ASD (non-amended control)] in the main plot and twenty sweetpotato genotypes in subplots. Three-week-old seedlings of tomato (cv. Rutgers) were planted in each microcosm followed by inoculation with 10,000 eggs of the southern root-knot nematode (Meloidogyne incognita). ASD was initiated one month post inoculation to allow nematodes to complete one life cycle. At the time of the ASD initiation, each microcosm was also inoculated with weed seeds [yellow nutsedge (10 tubers) and carpet weed (100 seeds)]. ASD was conducted for three weeks, followed by the transplantation of sweetpotato slips after one week of ASD termination. Weed counts, abundance of nematode second stage juveniles (J2) in soil, and sweetpotato above ground biomass data were collected. Our results suggested that the microcosms receiving the carbon amendment spent the most time under anaerobic conditions (

Entomopathogenic fungi offer an alternative strategy for citrus growers seeking environmentally friendly pest management solutions. This study aimed to assess the ability of a commercial strain of the fungus Beauveria bassiana to become endophytic in citrus plants after a single foliar application. A completely randomized block design, consisting of ‘Valencia’ sweet orange trees (Citrus × sinensis) grafted on ‘US-942’ (Citrus reticulata × Poncirus trifoliata) rootstock, was established under greenhouse conditions. Treatments comprised 6 replications of treated plants in two separate greenhouses (n = 16 per greenhouse), along with one control (water only). Treated plants were foliar sprayed asynchronously with the fungus at the beginning of each experimental trial per treatment. To assess endophytism over time, a series of cohorts were destructively sampled every two months. Spore deposition was assessed using cover slips post-spray application of all treatments. Additionally, detached leaves collected post-spray were imprinted on potato dextrose agar (PDA), amended with dodine and bactericides, to determine spore coverage of the leaf surface by counting colony forming units. To assess endophytism, sterile samples of plant organs (i.e., leaves, stems, and roots) were placed onto PDA-dodine plates to allow detection of phenotypic mycelia. Results from the first cohorts indicated successful application of the fungi on the citrus leaves, and endophytism was assessed after two months. Additionally, no statistically significant changes were recorded in terms of plant height, root, stem, and leaf biomass, as well as stem girth. This project contributed to a clearer understanding of the long-term endophytic persistence of commercially available entomopathogenic fungi and their effect on plant growth in citrus trees. The trial will continue in the field for additional screening.

Biosolids, derived from treated sewage sludge, represent a significant resource in sustainable agricultural production, with approximately 70 percent being utilized for land application in the United States. Recognized for their potential as organic fertilizers, biosolids undergo meticulous processing to meet grade AA standards before being blended with locally sourced organic materials, such as woody yard debris, in preparation for municipal distribution. This study delves into the effects of biosolids on soil and seed germination rates using various concentrations ranging from 1% to 7%. Findings reveal that higher concentrations of biosolids in soil significantly delay the germination of lettuce seeds. Through replicated mesocosm experiments at the Southwest Florida Research and Extension Center (SWFREC), UF/IFAS, Immokalee, we evaluate the effects of biosolids on lettuce (Lactuca sativa) growth and physiology. Lettuce was cultivated in 17cm tall pots filled with the soil amendments of biosolids compost in concentrations of 1%, 3%, 5%, and 7% (v/v) over a 60-day period. Comprehensive data collection includes measurements of plant height, leaf chlorophyll content, photosynthetic gas exchange, leaf area index (LAI), fresh and dry plant biomass, visual ratings, and spectral reflectance data at 340-2500 (nm) with a portable spectroradiometer. Data analysis of weekly and post-harvest collected data analyzed the implications of biosolid usage in agriculture, shedding light on significant effects on crop productivity, soil health, and agricultural sustainability. Keywords: Biosolids, Organic Fertilizer, Soil Contaminants, Lettuce (Lactuca sativa), Plant Physiology, Agricultural Systems

Digging into Clover Living Mulch Effects on Soil - Connor Ruen
Effects of Mulch Type on Day-Neutral Strawberry Yield and Quality in an Organic Production System in the Upper Midwest - Mary Rogers
The Nebraska Urban Soil Health Initiative: Combined Effects of Cover Crops, No-till, Compost, and Biochar on Soil Health and Vegetable Crops - Collin Eaton
HydroMulcH2O: A Novel, Certifiably Organic, Biodegradable Mulch Technology for Northern Highbush Blueberries - Ben Weiss
Effect of Plastic Mulch, Living Mulches and Cover Crops on Soil Characteristics, Weed Pressure and Yield in Organic Globe Artichokes Production - Arianna Bozzolo
Eastern South Dakota Early Season Soil Tarping Impacts on Soil Microbiology - Hannah Voye

Living mulch research has focused on crop health without digging in to the effects on soil health. Soil management influences soil structure, water infiltration, and compaction. The recent drought has affected the Great Plains where precipitation is already limited. This makes it important for the water to infiltrate into the soil instead of running off, taking nutrients along with it. Soil compaction limits plant root’s ability to reach ground water and nutrients deeper in the soil profile which are needed during dry spells. In this study, living mulches of three established clover varieties, ‘Domino’ white clover (WC) (Trifolium repens), ‘Aberlasting’ white x kura clover (KC) (T. repens x ambiguum), and ‘Dynamite’ red clover (RC) (Trifolium pratense), bare ground control (BG), in combination with in-row management of tilled (T), no-tilled (NT), tilled fabric (TF), and no-tilled fabric (NTF) were evaluate for water infiltration, soil compaction, soil temperature and moisture. Water infiltration was measured using a 25.4 cm PVC ring which was pounded in the ground to prevent lateral flow. Water was added every minute to measure the infiltration rate. Soil compaction was measured using a SpotOn soil penetrometer measuring the PSI needed to pass through the soil. Soil moisture and temperature were measured every hour using HOBO MX soil moisture and temperature logger. Water infiltration in NT soil management had a was 67% greater when compared to T soil management. Soil compaction readings from 0-15 cm had a range from 324 PSI in NT to 351 PSI in NTF. After one year of changing the soil management, there was a significant increase in on water infiltration rate in the NT which means the soil can handle much larger volumes of water compared to T. Soil compaction has changed very little between soil managements which can be expected since it takes many years to break compaction layers and improve the soil structure. Soil management can improve water infiltration rates which increases the water added to the soil and decreases the risk of erosion. More time is required to determine how soil management will affect compaction in this study.

Organic, locally produced strawberries are in high demand in the Upper Midwest. Day-neutral cultivars fit well within an annual production system, allow growers an extended harvest period, and previous research shows they can be productive in our region. However, key production challenges limit adoption of organic production of day-neutral strawberries including weed, insect, and disease pressure. To address these challenges, we established controlled experiments investigating the effects of four different mulch types: white-on-black poly (standard), black poly, reflective metallic poly, and biodegradable paper mulch on yield and quality of ‘Cabrillo’ strawberries across two years (2022 and 2023) and two locations (Madison, WI and St. Paul, MN). Our results show that strawberry yield ranged from 5,000 - 18,000 lbs per acre across treatments and years. The highest yields were achieved in 2023 in Wisconsin in the reflective metallic poly treatment, which was significantly different from the white-on-black treatment in the same year. Proportion marketable yield was equal between treatments in both years in Wisconsin and in 2022 in Minnesota, however we observed a significant decline in marketable fruit quality in Minnesota in 2023 under the paper treatment compared to black plastic.The paper mulch broke down before the end of the production season in Minnesota in both years which led to increased weed pressure and reduce fruit quality; however paper mulch retained at least 90% coverage and integrity in Wisconsin across both years. Tarnished plant bugs (TPB) are a key pest in this system and will significantly reduce fruit yield and quality if not managed. In both Minnesota and Wisconsin, TPB damage was higher in our standard white-on-black poly compared to the reflective metallic poly mulch in both years. In addition, thrips counts were significantly higher on white-on-black poly compared to reflective metallic poly in Minnesota in both years. Anthracnose fruit rot was the most common disease observed and was most common in the white-on-black poly treatment. Anthracnose was also a significant problem on row edges where weeds were actively growing and retaining moisture near the fruits. Overall, reflective metallic poly mulch significantly reduces strawberry insect pest pressure while maintaining yield and fruit quality and outperforms the current grower standard white-on-black plastic mulch. Price premiums for organic strawberries marketed direct by growers combined with the longer day-neutral production season, make day-neutral strawberries financially lucrative despite production issues and high labor requirements.

Adoption of soil health management practices like cover crops, no-till, and organic soil amendment is increasing in rural agroecosystems, but less in known about whether urban farmers and gardeners are using these practices and how implementing these practices might influence their soil. To address this knowledge gap, we started the Nebraska Urban Soil Health Initiative to 1) benchmark soil health and current management practices in urban gardens throughout Nebraska, and 2) evaluate the effects of adding new soil health management practices on urban soil health and crop performance. Using a citizen-science approach, we recruited and have retained over 300 participants who collect annual soil samples, complete surveys about their practices and knowledge, and implemented an assigned soil health management practice. Soil health management practice treatment groups ranged from low (e.g., individual practices) to high management intensities (e.g., combinations of practices) and include: 1) a cover crop mixture; 2) no-till with geotextile fabric; 3) compost soil amendment; 4) biochar soil amendment; 5) cover crop mixture no-till; 6) cover crop mixture no-till compost, or 7) cover crop mixture no-till compost biochar. Prior to implementing, most participants (>70%) had positive perceptions about cover crops, no-till, and compost soil amendment, whereas >60% had no opinion or prior knowledge about biochar soil amendment. Over 50% of participants characterized their garden weed pressure as somewhat to very high and over 60% reported very low to low pesticide use, which suggests room for improvement using cover crops and a no-till weed barrier. Baseline soil P across gardens was 186 mg/kg (above a sufficiency level of 25 mg/kg in 98% of gardens) and average soil organic matter was 6.9%, which suggests a legacy of compost amendment to meet crop nitrogen needs. Biochar soil amendment (8 tons/acre) alone reduced zucchini yield by 37%, but yield loss was avoided by pairing biochar with compost and the weed barrier. Initial changes in soil health among participant gardens following implementation of new practices in year one will be analyzed along with year two sweet corn crop response.

Utilizing single-use polyethylene (PE) mulch in agriculture is controversial due to concerns with plastic waste generation and pollution. An alternative option to PE mulch is hydromulch (HM), which is paper-based, biodegradable, and potentially could be certified organic. HMs can be produced from water, recycled paper, and organic-approved tackifier(s). The objective of this experiment was to determine the efficacy of different HM formulations on yield, fruit quality, mulch coverage, and weed suppression in a mature planting of northern highbush blueberry (Vaccinum corymbosum ‘Valor’) grown in eastern Washington. Using a randomized complete block design with four replications, four mulch treatments were tested: (i) HM with 4% guar gum, (ii) HM with no tackifier, (iii) paper mill slurry, and (iv) woven PE mulch (hereafter “weedmat”). The papermill slurry was made by agitating recycled paper with water and sodium hydroxide until the paper was pulped and ink removed. Yield, fruit firmness, titratable acidity as percent citric acid, total soluble solids, and pH were similar across all treatments. Mulch coverage measured as percent soil exposure was greatest for the slurry, followed closely by the 4% tackifier and no tackifier treatments. Weedmat had the lowest percent soil exposure. All treatments mostly suppressed dicot weeds, however, the no tackifier and slurry treatments had the greatest dicot numbers. The 4% tackifier suppressed nearly all dicots. HMs struggled to suppress monocots, with the slurry and no tackifier treatments performing the worst at monocot suppression. The 4% tackifier treatment was better than the other HM formulations, however, it had little-to-no effect on nutsedge (Cyperus esculentus) while weedmat suppressed all monocots. Weed biomass data revealed different patterns with the 4% tackifier treatment having similar weed biomass compared to the slurry and no tackifier treatments. This was likely due to lack of competition, as when weeds penetrated the 4% treatment they did not have other plants to compete with, and thus accrued biomass much faster than weeds in the slurry and no tackifier treatments. Although weed and fruit quality was maintained, future research should focus on increasing HMs ability to suppress nutsedge and other vigorous weed species.

: Standard organic farming production practices for specialty crops frequently involve the use of polyethylene plastic mulch or mechanical soil disturbance to reduce weed competition and enhance crop yields. Although successful, these practices come with environmental consequences, including soil pollution and loss of soil organic matter. As such, alternative methods that prioritize the long-term health of the soil and minimize environmental impact are needed. We performed a field experiment to assess and compare the influence of five soil management systems on soil characteristics, weed pressure and yield in globe artichokes production. Artichoke (Cynara scolymus L.) seedling cvs. Tavor were established on raised beds as: A) intercropped with white clover (Trifolium repens L.) as living mulch, or B) intercropped with crimson clover (Trifolium incarnatum L.) as living mulch, or C) transplanted into mixture of buckwheat (Fagopyrum esculentum M.) and pea (Pisum sativum L.) cover crop residue or D) intercropped with Kurapia (Lippia Nodifera L.) as living mulch, or E) transplanted in PE plastic mulch. Results show that white clover increased soil organic matter (SOM), soil potassium and manganese content, water extractable carbon, soil respiration (CO2), soil nitrate, ammonium and total soil nitrogen compared to plastic mulch at 360 DAS (Days After Seeding). White clover weed suppression ability did not differ from crimson clover and buckwheat/pea mixture. Crimson clover increased SOM at preharvest sampling. Both clovers decreased artichokes yield per plant when compared to plastic mulch. Kurapia increased soil sodium content compared to plastic. Cover crop/reduce tillage system increased SOM at 120 DAS compared to plastic. Due to biomass decomposition, the suppression ability of this mixture decreased over time. Plastic mulch increased copper and iron soil concentration. Artichoke yield from plants grown on plastic mulch had comparable bud weight and yield to buckwheat/pea mixture and Kurapia. The potential to enhance soil nitrogen and carbon levels over a longer period of white clover makes it a valuable choice in systems aiming to improve soil fertility. Crimson clover emerges as the most promising among the clovers, exhibiting less competition compared to white clover, effective weed control, and, although the yield is lower than that achieved with plastic mulch, it maintains a well-balanced crop load. The reduced tillage system has shown promising results, successfully managing weeds adequately and allowing for a satisfactory level of production. No detrimental impact on yield were found intercropping artichokes with Kurapia and, but its effect on soil health was limited.

Solarization and occultation are weed management strategies used by growers across the globe. However, there is not a large amount of literature discussing the impacts of this weed management practice on soil health. This study evaluated the impact of tarp materials and duration of tarp coverage on soil microbiology. Field experiments were conducted in the 2023 growing season in Brookings, South Dakota. Solarization was conducted using clear tarps secured with sandbags and buried edges. Clear tarps were placed early spring for six, four, and two weeks before tarp removal in May. Immediately following tarp removal, each plot was tilled, and rows of onion transplants were planted. Occultation was conducted using white side up and black side up silage tarps, both applied for six, four, and two weeks before removal and planting onions. These treatments were organized in a randomized complete block design with four blocks and ten treatment plots per block including a control with no tarp. Temperature and moisture data were taken in treatment plots using HOBO temperature and moisture sensors during tarping as well as during the growing season. Soil samples were taken before tarp application to observe organic matter and basic nutrients. Samples were also collected in each treatment plot after tarping and at the end of the growing season to determine differences in organic matter, basic nutrients, soil respiration, permanganate oxidizable carbon, and nitrogen. Solarized plots showed trends of higher temperatures during tarping compared to occultation plots. Solarized plots showed higher soil moisture trends during tarping and lower moisture trends during the growing season. Occultation tarp treatments showed trends of lower moisture during tarping and higher moisture during the growing season. No significant differences were seen between tarp treatments for soil respiration, permanganate oxidizable carbon, and nitrogen. While soil tarping can manipulate soil microbiology, more research is needed to determine the full extent of these impacts.

Biostimulants Promoted Onion Plant Growth and Helped Mitigate Drought Stress During the Seedling Stage - Genhua Niu
Effluent of the Anaerobic Digestion of Food Waste as a Biofertilizer for Red Cabbage - Roland Ebel
Optimizing the Application of Anaerobic Soil Disinfestation in Organic High Tunnel Vegetable Production Systems - Francesco Di Gioia
Cover Crops Potential for Regulating Soil Moisture and Temperature in Drive-row of an Irrigated Organic Vineyard - Mehdi Sharifi
Apple Rootstocks Affect Soil Rhizosphere Microbial Communities and Root Exudate Composition - Julie Cardon
No-till planting organic dry bean into rolled-crimped cover crops - Matthew Ryan

Climate change and global warming are increasing the frequency of drought incidents, which negatively impact crop production. Onion is one of the major vegetable crops produced in Texas, which requires a long growth period and prone to drought stress as it has shallow roots and needs frequent irrigation. Plant biostimulants may offer a potential solution to mitigate drought stress in onion production. This study investigated the effect of different biostimulants (no application as control, Kelpak, Spectrum DS, MycoApply, and Tribus Continuum) on onion seedling growth under well-watered and drought stressed (50-60% field capacity) conditions. Results showed that there was no significant interaction between biostimulants and drought stress on most of the parameters we collected. All biostimulants significantly increased shoot weight, leaf area, plant height, and root weight compared to the control. Notably, Spectrum DS, MycoApply, and Kelpak specifically enhanced root morphology by increasing root length, root area, and root volume compared to the control. But the application of biostimulants didn’t significantly affect average root diameter or the number of root tips. Drought stress significantly reduced the growth of onion seedlings across all measured parameters, except for the number of root tips, compared to the well-watered group. While drought stress caused a 36.9% decrease in shoot fresh weight, application of Kelpak, Spectrum DS, MycoApply, and Tribus Continuum increased shoot fresh weight by 29.8 to 34.9%, partly offsetting the growth reduction and alleviating the stress experienced by the seedlings. In conclusion, the application of the investigated biostimulants shows promise for enhancing drought tolerance in onion seedlings.

Food and farm waste processed by anaerobic digestion (AD) generates a nutrient-rich digestate suitable for use as a biofertilizer. Small-scale AD systems production of biofertilizer offer an on-site solution accessible to individual households and small horticultural producers. Unlike common and more complex AD solutions, small-scale systems do not require extensive management or infrastructure investments. In 2022, we investigated the nutrient content and usability of digestate from two small-scale biodigester models: A commercially built digester with a 1,200 L digester tank, and a prototype we designed with a 114 L capacity. Locally sourced fresh raw cow milk served as inoculum. Over a span of 16 weeks, 12 randomly selected households in Bozeman, Montana, tested the two digester models, feeding them with the food waste they generated. Six of the households received the commercial model, and six tested the prototype. Digestate samples were collected biweekly to analyze their chemical properties and potential as a biofertilizer. After 16 weeks, we blended all digestate, taking equal parts from all household samples, and tested it in a greenhouse study as a fertilizer for red cabbage (Brassica oleracea L. Capitata Group) seedlings. In addition to a control treatment where no biofertilizer was used, we applied 40 ml of biofertilizer per plant in a “high dose treatment” and 20 ml biofertilizer per plant in a “low dose treatment.” Each treatment involved 50 cabbage plants growing individually in trays of 10 cm diameter. On a weekly interval, the biofertilizer was sprayed on the substrate, with amounts varying by treatment. The substrate consisted of loam soil, washed sand, Canadian sphagnum peat moss, perlite, vermiculite, and dolomitic lime. Seedlings were irrigated manually every second day. To ensure sufficient nitrogen supply, all three treatments received an initial application of 40 mL of fish emulsion per cabbage plant. No pest or disease management practices were implemented. After 30 days, all plants were harvested, and their aboveground dry biomass was measured. A trend towards higher aboveground dry biomass in the "high biofertilizer dose" treatment compared to the "low biofertilizer dose" and control treatments was observed. Additionally, the aboveground biomass underwent nutrient content analysis, revealing a tendency towards the highest potassium content in the "high dose treatment." This study showed that household food waste processed through small-scale AD systems generates valuable biofertilizer that can help manage crops’ nutrient needs.

The growth of the U.S. organic vegetable industry is currently limited by the availability of viable and effective solutions for the management of soilborne pests and pathogens. Anaerobic soil disinfestation (ASD) is a pre-planting biological method proposed for the management of a range of soilborne pests and pathogens affecting horticultural crops. As an organic amendment-based approach, ASD is implemented incorporating in the soil an easily degradable carbon (C) source, tarping the soil with plastic mulch, and irrigating the soil to field capacity. The selection of organic amendments suitable as C sources is critical for the efficacy of the treatment and its sustainability. Understanding how the physicochemical properties of alternative amendments may affect the efficacy of the ASD treatment, the soil fertility during and post ASD, and consequently the crop performance is critical. Therefore, a study was conducted on organic-certified land at the Penn State High Tunnel Facility to compare wheat middlings (WM), molasses (M), and soybean meal (SM) and their combination as C sources. Treatments tested included WM, M, SM, WM SM, and M SM applied at the standard rate of 6 Mg/ha of total C, SM0.5 applied to reach the equivalent of 3 Mg/ha of total C, and the untreated controls with (UTC W) and without (UTC) initial irrigation. Three weeks after the ASD treatment, Romaine lettuce was planted as a test crop. Organic amendments tested as C source were characterized by different C:N ratio, ranging between 6.3 (SM) and 57.2 (M). All the amendments tested ensured the achievement of good soil anaerobicity levels. The C:N ratio of the amendments significantly influenced the availability of nitrate-N during and post-ASD, thereby influencing the lettuce crop yield and quality performance. Having the highest C:N ratio, M applied by itself decreased the availability of nitrate-N during and post-ASD. Instead, SM characterized by the lowest C:N ratio, increased the availability of nitrate-N. The availability of N during the growing cycle, determined by the characteristics of the organic amendment and by the ASD treatment influenced the crop yield and nutritional profile. The results of the present study provide new insight for the selection of alternative C sources and the optimization of the ASD treatment in organic protected culture systems.

The utilization of cover crops in vineyards has been promoted for their role in moderating soil climate, thus enhancing vineyard resilience to extreme weather conditions. This study evaluated the effectiveness of three drive-row cover crop treatments in regulating soil moisture and temperature within an irrigated organic vineyard characterized by loamy sand soil, located in the semiarid Okanagan Valley, Canada, over the period from 2021 to 2023. Selection of cover crop species was informed by prior greenhouse and field screening experiments. The implemented treatments, established in May 2021, included a mixture of perennial ryegrass, tillage radish, and white clover (PRTRWC); a fescue mixture with white clover (FWC); cereal rye with hairy vetch (CRHV); and a Control (existing vegetation/weeds). The vineyard was equipped with drip lines and undercanopy sprinklers. Soil moisture and temperature were monitored every four hours using Teros 11 sensors at a 10 cm depth in the drive-row. Seasonal observations revealed the highest soil volumetric water content (Ɵv) from November to April, aligning with cooler temperatures and increased precipitation. The Ɵv ranged from 0.10 to 0.14 and significant differences in average Ɵv were noted among the all treatments over the three growing seasons (May to Oct), with CRHV displaying the highest levels, followed by FWC, Control, and PRTRWC. Notably, substantial differences in Ɵv (

The plant rhizosphere plays a key role in plant function and immunity. Apple Replant Disease (ARD) is a dysbiosis in apple rhizosphere environments that have a history of apple cultivation. Due to increased intensification of apple growing systems and land scarcity, ARD incidence is on the rise and can result in a 50% loss of profitability to growers. Soil fumigation is a common practice for mitigating ARD, but has limited efficacy and is not allowed in some areas because of potential for environmental damage and human harm. Using resistant rootstocks is a key strategy in overcoming ARD. To understand rootstock resistance, it is important to describe and characterize the microbial communities of various rootstocks in an environment conducive to microbial health. We planted an organically managed apple orchard with 5 randomized repetitions of 15 different rootstocks. In both 2022 and 2023, we sampled the soil adhering to the roots of these trees for DNA extraction in order to characterize both bacterial and fungal microorganisms in the rhizosphere of the rootstocks in our research. We also established an aeroponic greenhouse trial (randomized with three repetitions) to sample rhizodeposits from 6 of the rootstocks used in the orchard trial, with the aim of characterizing metabolites with untargeted HPLC/LCMS. Bacterial phyla and genera differed in relative abundance between the rootstocks. A sparse PLS (partial least squares) discriminant analysis of rootstock exudates revealed differential sorting of some rootstocks. Neither study revealed clear biological indicators for ARD resistance, but the results evince that rootstock genotype does influence both microbial community and tree root exudation patterns.

Consumer demand for organic and locally sourced plant-based protein has created an opportunity for farmers in the Northeast and Upper Midwest who are interested in organic dry bean (Phaseolus vulgaris) production. However, standard practices for organic dry bean production can degrade soil health because of the soil tillage and cultivation used for weed management and harvesting. Such soil disturbance is not only labor and fuel intensive, but it also makes soil vulnerable to extreme weather, which is a major concern given the increased frequency of heavy rain events. Building on success with no-till planting soybean into mechanically terminated cereal rye, a team of researchers and stakeholders from Wisconsin, New York, Maine, and Vermont developed a project to assess dry beans for cover crop-based, organic no-till production. In addition to crop yield and profitability, field experiments focused on assessing weed and disease management. Findings from several experiments show that dry beans can successfully emerge through mulch from cover crops and produce yields that are comparable to standard tillage based organic production. In an experiment conducted at two sites in 2020-2021 and 2021-2022, a cover crop mixture of hairy vetch and cereal rye produced relatively high biomass (>7000 kg/ha), which suppressed weeds (< 500 kg/ha) and resulted in relatively high (2500 kg/ha) organic black bean (cv. ‘Zorro’) yield. Results are congruent with previous research showing that mulch from cover crops can suppress weeds, particularly small seeded annual weeds. In an experiment conducted in 2016-2017 and 2017-2018, we showed that mulch from mechanically terminated cereal rye (Secale cereale) can also reduce the incidence of the fungal disease white mold (Sclerotinia sclerotiorum) in organic no-till planted dry bean. Although mulch from cover crops can suppress weeds and soil borne diseases, achieving the high cover crop biomass production that is necessary for suppression can be challenging. A field experiment was conducted in Wisconsin, New York, Vermont, and Maine in 2022-2023 to test the efficacy of interrow mowing weeds that break through the mulch in the space between crop rows. Preliminary results show that interrow mowing has potential to reduce yield loss from weeds and weed seed production in organic no-till planted dry bean production. Additional research is needed to develop management guidelines for no-till planting organic dry beans into rolled-crimped cover crops.