Can living mulch enhance soil health and ecosystem services of organic vegetable production systems in South Dakota?

CAN LIVING MULCH ENHANCE SOIL HEALTH AND ECOSYSTEM SERVICES OF ORGANIC VEGETABLE PRODUCTION SYSTEMS IN SOUTH DAKOTA?

Sponsoring Institution

National Institute of Food and Agriculture

Project Status

COMPLETE

Funding Source

OTHER GRANTS

Reporting Frequency

Annual

Accession No.

1029000

Grant No.

NOT YET AWARDED

Cumulative Award Amt.

(N/A)

Proposal No.

2022-04691

Multistate No.

(N/A)

Project Start Date

Sep 9, 0999

Project End Date

Feb 12, 2025

Grant Year

(N/A)

Program Code

[NOT YET AWAR]- (N/A)

Recipient Organization
SOUTH DAKOTA STATE UNIVERSITY
PO BOX 2275A
BROOKINGS,SD 57007

Performing Department
(N/A)

Non Technical Summary
South Dakota stakeholders have expressed great interest in information on organic vegetable management strategies to improve profitability and ecosystem sustainability. To meet this need, it will require concerted efforts to generate science-based data for field demonstrations and ecosystem service evaluations. Specifically, barriers to production include climatic conditions, lack of knowledge on organic transitioning, and unknown performance of different organic management practices to maintain production and profitability through nutrient management and weed control, with lower reliance on organic manure and tillage. Thus, we proposed to investigate the feasibility and impacts of living mulch integration on agronomic performance, soil health, economic returns, and overall ecosystem services for organic vegetable production.The proposed project will be conducted at one South Dakota State University research farm and one farmer's field that are both at the organic transitioning stage, and one USDA organic certified farmer's field in South Dakota. It will address questions surrounding the incorporation of perennial clover species in vegetable cropping systems by trialing three varieties (red clover, white clover, and kura - white clover) as living mulch. Three different cash crops (squash, cabbage, and sweet corn) will be grown in rotation in the living mulch and four different tillage management practices will be used.Stakeholders will be closely involved in defining the problems, planning, participating in the study, and providing feedback. Dissemination of information will be to the specialty crop producers and associations, university and high school students, agency personnel, and other stakeholders through formal and informal extension and education channels.The research has the potential to improve the resilience of vegetable cropping systems in South Dakota by identifying new management strategies that utilize organic practices without compromising crop yield, while improving soil health and providing multiple ecological environmental benefits. This work will provide pertinent information in areas with short growing seasons, and therefore a small window for cover crop incorporation, as well as low soil organic matter and fertility, like South Dakota. Specifically, utilizing living mulch as a management option aims to benefit small vegetable farms with little organic manure resources and for those farmers adopting reduced tillage. The findings of this work will also be beneficial to other areas with low adoption of organic practices due to lack of transitioning and certificating information. We hope to promote organic vegetable production in South Dakota and other areas with similar climatic conditions and therefore contribute to growth of overall organic farming in the US. The data generated from this project will fill an important research gap in organic vegetable production and provide valuable information on sustainable vegetable production.

Animal Health Component

60%

Research Effort Categories

Basic

40%

Applied

60%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
102	0110	1070	20%
102	0110	2000	20%
204	1499	1010	20%
204	1642	1010	20%
601	6199	3010	20%

Knowledge Area
601 - Economics of Agricultural Production and Farm Management; 204 - Plant Product Quality and Utility (Preharvest); 102 - Soil, Plant, Water, Nutrient Relationships;

Subject Of Investigation
6199 - Economy, general/other; 1499 - Vegetables, general/other; 0110 - Soil; 1642 - Red clover;

Field Of Science
1070 - Ecology; 1010 - Nutrition and metabolism; 2000 - Chemistry; 3010 - Economics;

Keywords

organic vegetable production

Goals / Objectives
The goal of this project is to determine if using perennial clover cover crops as a living mulch can improve soil health, agronomic performance, and profitability of organic vegetable systems. This work will integrate the research, extension, and education objectives listed below:Objective 1. Soil analysis (soil health, fertility, organic carbon, and microbial activities). Objective 2 Agronomic assessment (yield, biomass, and nutrient uptake). Objective 3 Economic analysis. Objective 4 Extension and outreach (knowledge, research findings, and information distribution). Objective 5 Education (lectures, student training, youth education).This project will provide information and knowledge to producers and other stakeholders on sustainable organic vegetable management with lower reliance on manure and tillage. This could potentially increase the number of organic vegetable farms in South Dakota and other areas with similar barriers to organic transitioning.

Project Methods
The study will be conducted at three sites: 1) SDSU Southeast Research Farm, Beresford, SD, 2) Blue Sky Vegetable Co., Worthing, SD, and 3) Haroldson Farms, Bruce, SD. The research field at the SDSU Southeast Research Farm is in organic transitioning stage and will be USDA certified by 2024. Blue Sky Vegetable Co. (https://blueskyveg.com/) is operated by Kjersten and Dirk Oudman, in Worthing, SD. It has 25-acre CSA farm which has been managed without chemical input and uses non-treated seeds and will be certified organic in 2023. Haroldson Farms (https://haroldsonfarms.com/) is a family-owned produce farm and is USDA certified organic near Bruce, South Dakota. It is a farm.Treatment to be assessed at the SDSU farm will be full combinations of three types of living mulch (and a control without living mulch) and four types of tillage management. The experiment is a randomized complete block design with four replicates. Size of each plot is 30 feet × 40 feet. Three varieties of perennial clover species as living mulch (red clover, white clover, and a kura x white clover mixture) as well as a control without clover will be tested. Clovers will be planted in April, and cash crops will be seeded and grown as transplants and planted into the field by hand in May. Cash crops from the first to the third year in the trial will be squash, cabbage, and sweet corn. When squash is the cash crop, the living mulch will only be mowed at planting. When cabbage and sweet corn are the cash crops, mowing will occur throughout the growing season. Four tillage management practices will be evaluated: 1) Flail-mowing and 30" tillage strip, 2) Flail-mowing, 30" tillage strip, and 36" black landscape fabric, 3) Flail-mowing and 36" black landscape fabric, and 4) Flail mowing only. The tillage practices will be applied in May in the rows for cash crop planting.Trials at the private farmer sites will only use the red and white clovers, and the non-clover control, and will not include the new kura x white clover mixture. Each plot will be minimum 10 feet x 20 feet. To make it easier for farmers to operate, only one plot for each treatment will be established. Similarly, to make it simple, no tillage treatment will be applied on farmers' land. For the first two years, the cash crop grown by the farmers will be the same as in the SDSU trial. The third year of sweet corn planting will be optional.Objective 1. Soil analysis. Purpose: Investigate the impacts of perennial clover integration as living mulch on soil health indicators, soil nutrients, soil organic carbon stocks and distribution, and microbial community structure and activities in organic vegetable production systems.At the SDSU Southeast Research Farm, soils will be collected to a depth of 60 cm at the beginning and end of each trial to investigate changes in soil carbon stocks and nutrients after three years organic vegetable management using living mulch. The 0-10 cm soil will be used for soil health assessment including: 1) physical: moisture, macroaggregate stability; 2) chemical: pH, electrical conductivity, total and mineral nitrogen, extractable phosphorus and potassium, and 3) biological: microbial biomass carbon, potential mineralizable nitrogen and carbon, soil organic carbon, enzyme β-glucosidase activity. Soils from the SDSU trials will also be collected at 0-10 cm every year in spring to analyze labile carbon fractions and microbial community.Soil in farmers' fields will be collected at 15 cm in Spring 2023 before planting cover crops, and every spring until 2026. The soils will be sent to Ward Laboratories, Inc. Soil organic carbon, total nitrogen, pH, nitrate nitrogen, phosphorus, potassium, and other nutrients (calcium, magnesium, sodium, sulfur, zinc, iron, manganese, and copper), and microbial community structure (PLFA) will be analyzed.Objective 2 Agronomic assessment. Purpose: Study living mulch biomass, cash crop yield, nutrient uptake, plant quality, and weeds as influenced by selection of clover species and tillage methods.At the SDSU Farm, clover and weed biomass will be evaluated separately for alley and cash crop rows during the growing season. Samples will be sorted into weed and cover crop biomass, dried using a forced air drying oven, and weighed to assess dry matter. It is anticipated that biomass will be collected at least four times throughout the growing season. Crop yield will be assessed by harvesting cash crops at horticultural maturity over several days, not to exceed four harvest events at which time all produce will be removed during the final harvest, and all plants will be harvested and graded to determine a count and weight of marketable and un-marketable cash crops. Prior to the final harvest of either cash crop, the plant height will be measured; additionally, cash crop plant biomass will be collected. These data will aid in understanding treatment effects on cash crop plant growth and yield. One composited clover and one cash crop sample from each plot will be collected in September/October before cash crop harvesting for measuring nutrient uptake. On farmers' sites, similar analysis will be conducted with three samples to be collected from each treatment plot. Objective 3 Economic analysis. Purpose: Estimate the input costs, output prices, and overall profitability at transitioning stage in organic vegetable production, and/or early stages of living mulch integration.Total revenue will be calculated by multiplying crop yield with crop price reported by the average USDA NASS price of the harvested year. We will calculate the potential benefits of living mulch under organic systems, which include: 1) reduced fertilizer cost for the cash crop, 2) reduced herbicide/pesticide costs, and 3) yield/farm revenue increase from consequent cash crop. Farmers will be provided with the economic profit information of cash crop only, of living mulch only, and of a combination of both factors. Furthermore, producers will obtain information regarding economic effects of tillage on cover crop field.Objective 4 Extension and outreach. Purpose: Organize field days and webinars to demonstrate field management and distribute findings from the study to increase the impact and the adoption of living mulch integration practices. Provide knowledge, technologies and information on organic vegetable production, organic transitioning, and USDA organic certifying processes to promote organic vegetable production in South Dakota.In July 2023-2026, research field days will be held at the SDSU Southeast Research Farm for field demonstration. In both August 2024-2025, one of the two participating farmers will host on-farm field day on their farm. In January 2024 to 2026, webinars will be presented virtually to provide intensive science-based production information for small and medium-scale producers. During both 2025-2026, there will be at least one SDSU Extension web article published, three social media posts highlighting project progress, and one in-field video (3-5 minutes in length) to be posted on the SDSU Extension YouTube Channel.Objective 5 Education.Purpose: Offer lectures for university students to gain knowledge of organic vegetable production. Train students through participation in research projects. Provide tours to undergraduate and high school students to introduce organic vegetable farming.The project team will give at least two guest lectures for SDSU undergraduate and graduate courses: e.g., Organic Food and Plant Production, Introduction to Sustainable Agriculture, Environmental Soil Management (. This research project creates the opportunity to host in-person tours and engage in science communication with a secondary audience above and beyond specialty crop producers.

Progress 09/01/22 to 02/12/25

Outputs
Target Audience:The audience includes students, farmers, researchers, and extension personnel who are interested in sustainable agriculture and organic vegetable projection. Research goals, experimental designs, project progress and preliminary data were introduced to audience at Field Days and tours held at Beresford, Southeast Research Farm, and Blue Sky Vegetable Co. Knowledge of organic management has been introduced to students in undergraduate and graduate courses. Information associated with this research project was distributed to the audience through extension publications, online videos, seminar presentations, virtual courses and other outreach products. The audience includes students, farmers, researchers, and extension personnel who are interested in sustainable agriculture and organic vegetable projection. Research goals, experimental designs, project progress and preliminary data were introduced to audience at Field Days and tours held at Beresford, Southeast Research Farm, and Blue Sky Vegetable Co. Knowledge of organic management has been introduced to students in undergraduate and graduate courses. Information associated with this research project was distributed to the audience through extension publications, online videos, seminar presentations, virtual courses and other outreach products. Changes/Problems:The selection of vegetable main crop was adjusted to the interest of farmers on the farmers sites. More varieties were planted. The squash plant, which was the initial plan of the year 1 planting, was also included in their fields. Due to the drought weather, cover crops were replanted in some fields. One of the farm participants wanted to restart a new trial along with the previous established trail remain being used. With that, we collected soil from both trials on this farm and will continue managing both for next year. What opportunities for training and professional development has the project provided?Three graduate students were trained in field establishment, maintenance and management in organic vegetable projection systems. One graduate student is trained in soil sampling, lab analysis, instrument operation, and data analysis. All students have gained experience of giving field talks and conference presentations. Audience from this project, including farmers and other stakeholders, obtained knowledge and information on sustainable organic farming, and extended network to know each other for future communications. PIs from this project gained knowledge through participating conferences and workshops. How have the results been disseminated to communities of interest?Preliminary results were shared with the public through outreach events such as field day tours and talks, extension publications, videos and short courses, and conference presentations. Details can be shown in Products and Accomplishments sessions in this report. Moreover, the research team has also been meeting with the participating farmers to report the progress on data collection and analysis. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Objective 1. Soil analysis. 50% accomplished? Soil samples were collected in 2022 and 2023 initiated trials at 60 cm before field establishment and then collected at 0-10 cm in 2023, 2024. The baseline soils for trial 2022 were analyzed for Nitrate N, P, and K. The highest Nitrate N in 2022 was about 30ppm, dropping to below 20 ppm in 2023 and about 10 ppm in 2024. P decreased from about 100 ppm in 2022 to lower than 100 or lower than 80 under some treatments in 2023 and 2024. K also decreased from higher than 350 ppm in 2022, to lower than 350 ppm in 2023 and 2024. Under no till 2023, nitrate N was highest under white clover, P was highest from kura clover plots, and K was the highest under red clover. Soil total carbon and nitrogen increased from baseline in 2022 to 2024 in some no-till plots. In 2022, carbon concentration was about 30-35 g/kg, increasing to above 40 g/kg in some no-till plots. The total nitrogen was about 5 g/kg in 2022 and was above 5 g/kg in 2024. Similar trends were also observed in trial 2023, which showed an increased enzyme activity (β-glucosidase activity) of above 200 µg pNP g-1 soil h-1 in many plots in 2024 than below 160 µg pNP g-1 soil h-1 in 2023. On farmers' fields, soil sampling was conducted in 2023 and 2024. Results showed a decrease in nitrate, P, and K in 2024 compared to 2023. However, there was a slight increase in soil microbial activity, including total bacterial biomass, actinomycetes biomass, and total fungal biomass, in 2024. Impact: Maintaing soil health, especially soil nutrients, is essential for sustainable organic farming. A good strategy of management with the potential of improving soil health may improve organic farming in this location. Objective 2 Agronomic assessment. 70% completed In squash trials at the Southeast Research Farm, due to limited moisture and heavy weed competition, clover struggled to take off and weeds overcame the project site. Red clover had the tallest height among the clover treatments. Weed biomass decreased throughout the season. Marketable squash yield was reduced in the no till plots for clover treatments. Kura clover treatments produced significantly fewer squash compared to other clover treatments. Marketable squash harvested from the red clover plots produced the most fruit per plant compared to white clover and kura treatments. For cabbage trial, cabbage in the no till treatments have shown signs of stem elongation and reduced growth with a lack of head development. From May and June 2023, red clover had greater biomass and weed biomass continued to trend towards higher pressures in the clover treatments compared to the tilled bare ground in August and September. In 2024, the clover whole block living mulch was successful at suppressing weed accumulation throughout the season. Clover biomass was the highest for the white clover treatment, being 150% greater than kura clover and 214% greater than red clover. The bare ground had the highest count of marketable heads, with 155 US Number 1 heads, and 75 Commercial heads, followed by white clover, kura clover and then red clover. In the corn fields in 2024, white clover was also the best living mulch at suppressing weeds, accumulating only 594 kilograms/hectare (530 lbs/acre) of weed biomass over the growing season. Kura clover was second in suppression. The bare ground produced the highest yield of US Fancy ears at 7.3%. The red clover had the highest replicated percentage of unmarketable ears, with an average of three unmarketable out of the 15 ears analyzed. On-farm trials were established at Haroldson Farms (HF) and Blue Sky Farms(BSF). Because of lack of moisture and weed competition, the clover population quickly died off in 2023. The 2024 growing season cover crops and cash crop management have continued as planned. One farmer decided to have an adjacent field to redo the work in 2024. In HF, red clover was on average taller than white clover. There was little difference in weed height throughout the season. The weight of oats was higher in the red clover treatment by 136.7 pounds per acre. Red clover had almost 500 pounds per acre more biomass than white clover. Both clovers decreased the biomass of weeds compared to the bare ground. White clover performed best when it came to weed biomass suppression. Impact: This project will provide information and knowledge to producers and other stakeholders on sustainable organic vegetable management with lower reliance on manure and tillage. This could potentially increase the number of organic vegetable farms in South Dakota and other areas with similar barriers to organic transitioning. Objective 3 Economic analysis. 45% completed Since the start of the project, economic data has been recorded. This includes the tracking of costs and expenses for purchasing equipment, seeds, labor, and other input. Data will be transferred to digital format and will be used for economic analysis. One student will keep tracking remaining data. Another student has been trained by co PI Dr. Wang to learn how to organize data and will analyze the available data soon. Impact: Accomplishment of this objective will provide information for farmers with financial decisions on transitioning to organic farming for vegetable production. Objective 4 Extension and outreach. 85% completed. In 2022-2023, two field talks were given at Southeast Research Field Day, and five talks were given at other events (Cedar Creek Gardens Field Day, Garden Hour Presentation, 3rd Annual Specialty Crop Field Day, SERF High School Field Day, Dordt University Agroecology Class Tour). Two videos and four extension publications were given. In 2023-2024, the team hosted an Organic Field Day at Southeast Research Farm and also gave talks on the annual field day. Besides, four invited talks, three videos, three extension publications, three conference poster presentations and four Booth and farm forum were given. In 2024-2025, one field day was hosted at Blue Sky Vegetable Co. and talks have been given at the Southeast Research Farm field day. One report and three talks were given at other activities. One video and four extension publications were generated. Four oral presentations and two poster presentations were given at conferences. Impact: The distribution of our research progress and finding, as well as knowledge and techniques on managing organic farms, cover crops, living mulch, and sustainable vegetable production, is important for producers to have a better idea on decision making for their future farm management. Objective 5 Education (lectures, student training, youth education). 80% completed. From 2022 to 2023, sustainable agriculture and organic management has been introduced in courses Environmental Soil Management and Soil Health in Agroecosystems. From 2023 to 2024, Organic Plant Production was given, included three guest lectures on Organic Vegetable. Soil Health in Agroecosystems was given again with a guest lecture on Organic Agriculture. Besides, a virtual short course was given. Co PI Dr. Mahal from Texas A&M developed Sustainable Organic Horticulture course and offered it in the year 2024-2025. Organic Plant Production was given again in 2024-2025. Also, 2 virtual training and 3 short courses were given in the third year. Four graduate students (Nitish Joshi, Connor James, Alexis Barnes-graduated, Kristina Harms) and an additional graduate student/technician hired from Southeast Farm (Joslyn Fousert) have been working on the project. Three other students from PI Dr. Xu's lab have assisted in field work or lab training for this project). Students obtained training in field establishment, tillage management, sampling, data analysis, and experience on presentations. Impact: The educational objective of this project will help with educating next generation producers, researchers, scientists, and extension workers who need to learn concepts and updates on organic farming.

Publications

Type: Conference Papers and Presentations Status: Other Year Published: 2024 Citation: Joshi, N., Xu, S., Lang, K., Nleya, T. M., Sexton, P. J., Burrows, R., Wang, T., & Mahal, N. K. Assessment of soil health improvements through living mulch integration in South Dakota's organic vegetable production systems. Oral presentation at the ASA, CSSA, SSSA International Annual Meeting, San Antonio, TX. November 2024
Type: Conference Papers and Presentations Status: Other Year Published: 2024 Citation: Joshi, N., Xu, S., Lang, K., Nleya, T. M., Sexton, P. J., Burrows, R., Wang, T., & Mahal, N. K. Quantifying Soil Health Dynamics Under Living Mulch Integration and Different Tillage Practices in Organic Vegetable Production Systems in South Dakota (poster). ASA, CSSA, SSSA International Annual Meeting, San Antio, TX. November 2024.
Type: Conference Papers and Presentations Status: Other Year Published: 2024 Citation: Ruen, C., K. Lang, and T. Nleya. 2024. Lessons Learned from Living Mulch Trials on Midwest Vegetable Farms. Annual Conference. American Society for Horticultural Science. Honolulu, HI.
Type: Conference Papers and Presentations Status: Other Year Published: 2024 Citation: Lang, K. 2024. Room to Grow: What's Next for the SDSU Local Food and Flowers Extension and Research Program. Departmental Seminar. SDSU Natural Resources Management. Brookings, SD. 74 attendees.
Type: Conference Papers and Presentations Status: Other Year Published: 2025 Citation: Ruen, C., K. Lang, and T. Nleya. 2025. Digging Into Clover Living Mulch Effect on Soil. Annual Meeting. (Poster) Midwest Cover Crops Council. Mankato, MN.
Type: Other Status: Other Year Published: 2024 Citation: SDSU Extension. 2024. SDSU's Guide to Advanced Vegetable Production. South Dakota Ag Connection. southdakotaagconnection.com/news/sdsus-guide-to-advanced-vegetable-production.
Type: Other Status: Other Year Published: 2024 Citation: Integrating Living Mulch on Vegetable Farms in South Dakota: 2024 Results. SDSU Extension: P-00320-v2. extension.sdstate.edu/integrating-living-mulch-vegetable-farms-south-dakota-2024-results.

Progress 09/01/23 to 08/31/24

Outputs
Target Audience:The audience include students, farmers, researchers, and extension personnel who are interested in sustainable agriculture and organic vegetable projection. Research goals, experimental designs, project progress and plans were introduced to audience at Field Day held at Beresford, Southeast Research Farm. Knowledge of organic management has been introduced to students in undergraduate course Environmental Soil Management. Changes/Problems:The selection of vegetable main crop was adjusted to the interest of farmers on the farmers sites. More varieties were planted. The squash plant, which was the initial plan of the year 1 planting, was also included in their fields. Due to the drought weather, cover crops were replanted in some fields. One of the farm participants wanted to restart a new trial along with the previous established trail remain being used. With that, we collected soil from both trials on this farm and will continue managing both for next year. What opportunities for training and professional development has the project provided?Three graduate students were trained in field establishment, maintenance and management in organic vegetable projection systems. One graduate student is trained in soil sampling, lab analysis, instrument operation, and data analysis. All students have gained experience of giving field talks and conference presentations. Audience from this project, including farmers and other stakeholders, obtained knowledge and information on sustainable organic farming, and extended network to know each other for future communications. PIs from this project gained knowledge through participating conferences and workshops. How have the results been disseminated to communities of interest?Preliminary results were shared with the public through outreach events such as field day tours and talks, extension publications, videos and short courses, and conference presentations. Details can be shown in Products and Accomplishments sessions in this report. Moreover, the research team has also been meeting with the participating farmers to report the progress on data collection and analysis. What do you plan to do during the next reporting period to accomplish the goals?Soils collected from the past two years will be finished in analysis. Soils will be collected again in spring 2025. Agronomy data from Y2 will be collected. Economic data will be kept recorded for future analysis and the already collected data will start to be analyzed. Another field day will be conducted at a participating farm. Extension publications and other outreach activities will be continued. Education and Mentoring will be continued. One or two students may be graduated.

Impacts
What was accomplished under these goals? Objective 1. Soil analysis. ?45% accomplished? Soil samples were collected in 2022 and 2023 initiated trials at 0-60 cm before field establishment as baseline samples. After that, soil at surface (0-10 cm) was collected again in spring in following years from each replicated subplots under treatments of cover crop species and tillage management. Baseline soils for trial 2022 were analyzed for Nitrate N, P, and K, which were all the highest at top layer (0-10cm) and decreased at the lower depths. The highest Nitrate N in 2022 was about 30ppm, while it dropped to below 20 ppm in 2023 and about 10 ppm in 2024. Similarly, P decreased from about 100 ppm in 2022 to lower than 100 or lower than 80 under some treatments in 2023 and 2024. Moreover, K also decreased from higher than 350 ppm in 2022, to lower than 350 ppm in 2023 and 2024. The advantage of no till management, on the other hand, was shown in some soil nutrients under specific cover crop species, such as nitrate N in 2023 under white clover, and P in 2023 kura clover plots, and potassium in 2023 under red clover. Treatment effects, however, need to be further analyzed after statistical analysis is completed. Different from the soil nutrients, the soil total carbon and nitrogen was increased from baseline in 2022 to 2024. In 2022, carbon concentration was about 30-35 g/kg, and it increased to above 40 g/kg in some no-till plots. Total nitrogen, on the other hand, was about 5 g/kg in 2022, and was above 5 g/kg in some plots under no-till in 2024. Similar trends were also observed in trial 2023, which showed an increased enzyme activity (β-glucosidase activity) of above 200 µg pNP g-1 soil h-1 in many plots in 2024 than below 160 µg pNP g-1 soil h-1 in 2023. On the farmers' fields, baseline soil sampling was conducted in May 2023, at a depth of 0-15 cm, and the samples were taken again in 2024. Results showed a decrease in nitrate, P, and K levels in 2024 compared to baseline in 2023. However, there was a slight increase in soil microbial activity, including total bacterial biomass, actinomycetes biomass, and total fungal biomass, in the 2024 samples. Impact: Maintaing soil health, especially soil nutrients, is essential for sustainable organic farming. A good strategy of management with potential of improving soil health may improve organic farming in this location. Objective 2 Agronomic assessment. 65% completed For cabbage trial, clover biomass was collected six times from May to October 2023. From May and June, red clover had greater biomass than the kura or white clover. July trended towards a peak in clover cover crop biomass production and then decreased most likely due to the drought conditions experienced. In May, weed biomass was greater in the white clover plots compared to the bare-ground treatments. In June and July, bareground plots had greater weed biomass than clover plots. Weed biomass continued to trend towards higher pressures in the clover treatments compared to the tilled bare-ground during the months of August and September, possibly due to managing clover height with mowing allowing the weeds to demonstrate their ease in out competing clover in drought conditions. The use of landscape fabric did guard against yield reductions in some clover plots for both Farao and Famosa production; however there was a trend of steep yield reduction for cabbage grown in any of the three clover plots compared to bare-ground conditions. The no-till treatment rows did not yield desirable cabbage quality. This was not unexpected as the increased competition from the clover under no-till management greatly impacted cabbage growth. In squash trials, kura clover height and biomass was lower than other clover treatments, due to its low growing potential and rhizomatous root structure. Red clover had the tallest height among the clover treatments. White clover and kura height performed similarly due to their similar growing pattern. Weed biomass did decrease throughout the season presumably due to squash vine length and canopy outcompeting late season weeds. Marketable squash yield was reduced in the no till plots for clover treatments due to clover and weed competition. Kura clover treatments produced significantly fewer squash compared to the other clover treatments. Marketable squash harvested from the red clover plots produced the most fruit per plant compared to white clover and kura treatments. The 2024 growing season cover crops and cash crop management have been continued as planned and the data will be provided in the next report period. On the two farmers' fields, the cover crops were not established well due to drought, especially on one site. So the farmer decided to have an adjacent field to redo the work by establishing fields again in 2024. Impact: This project will provide information and knowledge to producers and other stakeholders on sustainable organic vegetable management with lower reliance on manure and tillage. This could potentially increase the number of organic vegetable farms in South Dakota and other areas with similar barriers to organic transitioning. Objective 3 Economic analysis. 45% completed Since the start of the project, economic data has been recorded. This includes the tracking of costs and expenses for purchasing the equipment, seeds, labor, and other input. Data will be transferred to digital format and will be used for economic analysis. One student (Kristina) will keep tracking the remaining data. Another student (Nitish) has been trained by co PI Dr. Wang to learn how to organize data and will analyze the available data soon. Impact: The accomplishment of this objective will provide information for farmers with financial decisions on transitioning to organic farming for vegetable production. Objective 4 Extension and outreach. 75% completed. The team hosted one Organic Field Day in Aug 2024. Tours were given on this research at two annual Southeast Research Farm field days (Sep 2023 and July 2024). Field presentations on field management and soil analysis were given at these events. Besides, four invited talks were given at other outreach events, including the events from other universities. Also, the team produced three videos, three extension publications, and four Booth and farm forum. Impact: The distribution of our research progress and finding, as well as knowledge and techniques on managing organic farms, cover crops, living mulch, and sustainable vegetable production, is important for producers to have a better idea on decision making for their future farm management. Objective 5 Education (lectures, student training, youth education). 70% completed. A course at South Dakota State university (SDSU) HO/PS 447/547 Organic plant production was given by co PI Dr. Nleya in Spring 2024 to introduce the concepts on organic farming. This course also included three guest lectures given by co PI Dr. Lang on the topic of Organic Vegetable Production. A course at SDSU PS792 Soil Health in Agroecosystems was given by PI Dr. Xu in Fall 2023, including a guest lecture given by Dr. Nleya talking about Organic Agriculture. Co PI Dr. Mahal from Texas A&M developed HORT 489 Sustainable Organic Horticulture course. Besides, a virtual short course on vegetable production has been given in Jan 2024. Four graduate students (Nitish Joshi, Connor James, Alexis Barnes, Kristina Harms) and an additional graduate student/technician hired from Southeast Farm (Joslyn Fousert) have been working on the project. Three other students from PI Dr. Xu's lab have assisted in field work or lab training for this project). Students obtained training in field establishment, tillage management, sampling, data analysis, and experience on presentations. Impact: The educational objective of this project will help with educating next generation producers, researchers, scientists, and extension workers who need to learn concepts and updates on organic farming.

Publications

Type: Conference Papers and Presentations Status: Other Year Published: 2024 Citation: Barnes, A., K. Lang, and R. Burrows. Integrating Early Season Clover Cover Crops as a Living Mulch in Broccoli and Organic Winter Squash Production. Marbleseed Organic Farming Conference. February 22, 2024. La Crosse, WI.
Type: Conference Papers and Presentations Status: Other Year Published: 2024 Citation: Lang, K. Horticulture Research Recap and 2024 Plans. SDSU Southeast Research Farm Board Annual Meeting. January 30, 2024. Virtual.
Type: Conference Papers and Presentations Status: Other Year Published: 2023 Citation: 3) Nitish, Xu, S., Lang, K., Nleya, T., Sexton, P., Burrows, R., Wang, T., Mahal, N. Soil health influenced by living mulch in organic vegetable production systems in South Dakota. ASA, CSSA, SSSA annual meeting, October 29-November 1, 2023. St Louis, Missouri.

Progress 09/01/22 to 08/31/23

Outputs
Target Audience:The audience include students, farmers, researchers, and extension personnel who are interested in sustainable agriculture and organic vegetable projection. Research goals, experimental designs, project progress and plans were introduced to audience at Field Day held at Beresford, Southeast Research Farm. Knowledge of organic management has been introduced to students in undergraduate course Environmental Soil Management. Changes/Problems:The selection of vegetable main crop was adjusted to the interest of farmers on the farmers sites. More varieties were planted. The squash plant, which was the initial plan of the year 1 planting, was also included in their fields. What opportunities for training and professional development has the project provided?Two graduate students were trained on field establishment, maintenance and management in organic vegetable projection systems. One graduate student is trained on soil sampling, lab analysis, instrument operation, and data analysis. Farmers got opportunities to speak with our research team and get suggestions on selection of crop species and management techniques. How have the results been disseminated to communities of interest?Since the project is at the early stage of field establishment. We don't have results to share yet. However, we shared the experience on field establishment to the audience. What do you plan to do during the next reporting period to accomplish the goals?Baseline soil analysis results will be accomplished by the next reporting period. The second set of soils will be collected. Agronomy data from Y 1 will be collected. Education and Mentoring will be continued. Another field day will be conducted. Economic data will be kept recorded for future analysis.

Impacts
What was accomplished under these goals? Objective 1. Soil analysis. ?25% accomplished? Baseline soils were collected from both university site and farmers sites. At Southeast Research Farm, soil was collected from 0-60 cm and divided into 4 depths. The soils were weighed to analysis bulk density. The fresh soils were kept at 4oC for analyzing soil moisture and microbial biomass carbon. Part of each soil was kept in freezer at -20oC for microbial community structure analysis. Part of each soil was air dried for carbon and total nitrogen analysis. Soil moisture from samples collected in 2022 in the 2022 initiated trial (T22) ranged from 0.11-0.30. The moisture range of soils from 0-10 cm were 0.23-0.27. The moisture data from this trial in 2023 ranged from 0.21-0.29. Since this trial was established before this grant was funded, bulk density data were not collected at that time. Soil moisture from samples collected in 2023 in the 2023 initiated trial (T23) ranged from 0.18 to 0.28. The moisture from 0-10 cm ranged from 0.18-0.25. The bulk density for the four layers are 1.1, 1.3, 1.3 and 1.3. The ongoing analysis of these soils are total carbon and nitrogen and microbial biomass, which are during the process currently and could be completed analysis by the end of this year. Other soil analysis will be conducted soon after that to ensure data is available to be compared with new soils to be collected next year. Baseline soils from farmers sites were collected at 0-15 cm in 2023 before planting cover crops, and they were directly sent to commercial lab to analyze microbial community structure and soil chemical properties. Data will be analyzed soon after they are received, and to be compared with soils to be collected next year. The sampling depth and analysis methods were selected to benefit farmers in future if they would like to monitor their soil health status. Objective 2 Agronomic assessment. 35% completed From the Southeast Research Farm, clovers were seeded Late April 2023. Unfortunately, due to limited moisture and heavy weed competition, the clover struggled to take off and weeds overcame the project site. Clovers were Re-seeded in Late June but did not establish like we wished. Weed populations were pretty high in the beginning of the season and started to decrease by the July 28th due to squash canopying. In September, weeds were considerable low visually (not statistically) in the in-row plots due to increased moisture and further squash canopying. Farmers should consider weather and soil moisture before proceeding with living mulches. Clovers can outcompete cash crops in no-till systems and struggle to establish if early Spring moisture is not consistent. Frost seeding may be a good option in certain areas. However, some positives, the squash crop was great with 62% of total squash harvested being marketable according to the USDA winter squash standards. 2330 pounds of winter squash was donated at the end of the 2023 field season to Feeding South Dakota. Focusing on the cabbage, we selected 3 varieties with three separate maturity date cabbage. The cabbage seeds were sourced from Johnny's Selected Seed and are all certified organic. The cabbage in the no till treatments have shown signs of stem elongation and reduced growth with a lack of head development. There have also been some differences noted in the observations regarding cabbage looper and white butterfly worm damage. Cabbage loopers and white butterfly worms this year have been a huge issue for the cabbage production. The decision to opt out of the use of row cover was made leading to a more intentional focus on an integrated pest management system (IPM). With this in mind, we decided to utilize the guard rows for beneficial flowers in hopes of drawing in beneficial insects. Crop scouting for the economic threshold levels were also completed for cabbage looper worms and the white butterfly worms.This led to utilizing a few applications of DiPel DF for control which is certified organic and on the OMRI approved list for use in the field. The harvest events that have occurred thus far demonstrated a difference between the Farao and Famosa regarding worm damage on the cabbage heads. The Farao were mostly damaged beyond marketability due to looper damage, while the Famosa thus far are looking far better. Looking at the data once all harvest events are complete will offer a more definitive direction within this area though. On-farm trials were established at Haroldson Farms(HF) and Blue Sky Farms(BSF). Both farms had a variety ofCucurbitaspecies grown within the clover plots. HF had threebiomass sample events, and BSFhadfour biomass sample events. Both on-farm trails had the clover established and were present at the first initial biomass collection. However, because of the lack of moisture and weed competition, the clover population quickly died off. HF mowed three times and BSF mowed once the first week of July after biomass collection to knock down weeds and allow light to reach the clover. Since the cash crops were vining plants the living pathways were not able to be mowed once they started trailing. Farmer's (HF) thoughts - moisture was lacking this year so irrigation will be needed to establish Clover next year. Lay plastic before seeding the clover and oat mix to prevent the 6-12" of soil from being exposed, allowing weeds to grow. Black plastic used for squash was too hot, stressing out the cash crops. (BSF) - Clover and oats were established well with a drill but were out-competed by a lack of moisture and weeds. Break ground on sod to establish clover before weeds can move in. For the 2024 season, we will be attempting to do frost seeding so the clover can be established as soon as conditions are favorable, and the snow melt will provide enough water for a strong tap root to grow. This head start will hopefully allow clover to outgrow any weed pressure as the season progresses. Objective 3 Economic analysis. 15% completed Economic data has been recorded along with the progress of this project. Costs and expenses for purchasing the equipment, seeds, labor, and other inputs were kept tracking, which will be used for economic analysis. The analysis will be conducted at the late stage of the project. Objective 4 Extension and outreach. 40% completed. Two field talks were given at Southeast Research Field Day in July 2023 by students from this project to introduce the goals, objectives, methods, progress of this project, and demonstrate the field set up. Other field day talks and presentations are: Cedar Creek Gardens Field Day ?Aug 2023?, Garden Hour Presentation (Aug 2023)?3rd Annual Specialty Crop Field Day (Sep, 2023), SERF High School Field Day ?Sep 2023?? Dordt University Agroecology Class Tour ?Oct 2023?. Objective 5 Education (lectures, student training, youth education). 25% completed. Lectures were given based on the PI's teaching opportunities. The concept of sustainable agriculture has been introduced in Environmental Soil Management undergraduate course in Spring 2023. The co PI of the project, Dr. Nleya, has given a lecture on Organic Management in Dr. Sutie Xu's graduate course Soil Health in Agroecosystems in Fall 2022. Three graduate students hired from this project (Nitish, Connor James, Alexis Barnes) and an additional graduate student/technician hired from Southeast Farm (Joslyn Fousert) started participating the project. They obtained training on field cover crop and cash crop establishment, tillage management, crop sampling, or soil sampling and analysis, depending on their focus of graduate project. This project will provide information and knowledge to producers and other stakeholders on sustainable organic vegetable management with lower reliance on manure and tillage. This could potentially increase the number of organic vegetable farms in South Dakota and other areas with similar barriers to organic transitioning.

Publications