Source: LINCOLN UNIVERSITY submitted to NRP
IMPACT OF LONG-TERM COVER CROPPED ORGANIC FARMING PRACTICES ON THE DEVELOPMENT OF DISEASE SUPPRESSIVE SOILS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
ACTIVE
Funding Source
OTHER GRANTS
Reporting Frequency
Annual
Accession No.
1028968
Grant No.
2022-51300-37883
Cumulative Award Amt.
$749,331.00
Proposal No.
2022-04046
Multistate No.
(N/A)
Project Start Date
Sep 1, 2022
Project End Date
Aug 31, 2026
Grant Year
2022
Program Code
[113.A]- Organic Agriculture Research & Extension Initiative
Recipient Organization
LINCOLN UNIVERSITY
820 CHESTNUT ST
JEFFERSON CITY,MO 651023537
Performing Department
(N/A)
Non Technical Summary
Current organic systems depend on various management practices such as crop rotation, cover crops, use of composts and other soil amendments to develop healthy soils that are supposedly able to suppress pathogens and plant diseases. While there is extensive information about the individual amendments and practices and their role in soil health and disease suppression, there is very little information about the systemic role of organic farming systems to maintain soil health and suppress diseases. Moreover, the long-term organic management practice might also have a significant impact on these properties. In this project, we propose to fill this gap in knowledge and evaluate a chronosequence of soils maintained under organic farming using cover cropping practices for their ability to preserve or improve soil health and also impart resistance to pathogens and diseases. We expect that the benefits of long-term use of cover crops will create a dynamic and biodiverse habitat for beneficial soil microbial populations within the rhizosphere of such production systems. Diverse lab analysis and field studies information on soil-plant relatinship systems will be collected to develop tools to quantify supporting (nutrient fixation and recycling, soil health), and regulating (disease suppression) functions of organic cover cropped soils. Educational and outreach programs will include providing internship opportunities, training minority undergraduate and graduate student, attendance and presentations at annual meetings, train the trainer workshop, field days, publications, and a presence on the internet and in social media.
Animal Health Component
60%
Research Effort Categories
Basic
20%
Applied
60%
Developmental
20%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
10201992061100%
Knowledge Area
102 - Soil, Plant, Water, Nutrient Relationships;

Subject Of Investigation
0199 - Soil and land, general;

Field Of Science
2061 - Pedology;
Goals / Objectives
Our long-term goal is to utilize an integrated approach for research, education, and extension to develop a deeper understanding of disease suppressive ability imparted by a chronosequence of organic farming systems. This project will generate science-driven knowledge, guidance, and tools to better assess the capability of long-term organic management to impart disease suppressibility. Specific objectives are to:1. Quantitatively measure soil physico-chemical properties, and soil health indicators under cover cropped plots using different spring termination methods (Research objective)2. Generate a complete soil chemical profile using metabolomics approach (Research objective).3. Assess the disease suppression capability of soil maintained under a chronosequence of organic farming practices (Research objective).4. Develop and conduct educational and outreach programs to enhance stakeholderknowledge of innovative organic systems that improve soil health and ecosystem services; provide internship opportunities for high school students; train undergraduate and graduate students (Education and Extension objective).
Project Methods
Objective 1: Quantitatively measure the soil physico-chemical properties and soil health indicators under cover cropped plots using different spring termination methods (Research objective).Treatments: The following cover crop termination treatments and two controls will be evaluated: (1) crimper rolled, (2) occultation (3) flail mowed, (4) sickle bar mowed, (5) rotary mowed (6) black plastic mulch on tilled soil (control 1) and (7) bare tilled soil (control 2). Each treatment will be replicated four times following a randomized block design.Site Preparation, Fertility, Irrigation management: The research site has been cover cropped over the past six years. In early September each year, an area will be disked and tilled as necessary to facilitate a seeding bed for cover crops in treatment plots. Each treatment unit will comprise a 20 feet-long raised bed created with a bed hiller/shaper at 48" width. In control plots for summer squash transplant beds, a mixture of hairy vetch and rye will be broadcasted and harrow-incorporated to simulate standard organic grower practices. In treatment plots, hairy vetch and cereal rye will be planted with a push seeder in September down the length of each bed seeded in alternating rows on 5" centers. The area between the beds will be 72" wide to facilitate tractor mowing, and it will be planted with rye and a biennial clover. These bed alleys will be broadcast-seeded and incorporated through harrowing. Bed alleys will be planted in fall and mowed the following spring and as needed throughout the growing season to reduce competition with the cash crop and ease foot traffic. Soil physical, chemical, and health indicator parameters including microbial diversity and enzymatic activities will be measured under each treatment using appropriate methods.Objective 2: Generate a complete soil chemical profile using metabolomics approach (Research objective).The chemicals in the rhizospheres will be extracted by MeOH and analyzed by ultra-high pressure liquid chromatography coupled with high-resolution mass spectrometry (UPLC-HRMS). The ion chromatograms will be submitted to XCMS platform operated by the Center for Metabolomics at the Scripps Research Institute. The peak detection, peak grouping, spectra extraction, and retention alignment will be processed by XCMS. The spectra will be annotated, and the compounds identified and categorized by integrating the METLIN, the world's largest metabolite database. Multivariate analysis and principal component analysis (PCA) will be performed by XCMS to compare the chemical profiles of the treatments. Each identified compound will be assigned and related to its biological pathway through XCMS biological pathway/network analysis.Objective 3: Assess the disease suppression capability of various soils maintained under a chronosequence of organic farming practices (Research objective). Experiments will be conducted in 2023, 2024, and 2025 to evaluate disease suppersibility of soils manintained under orgaic cover crop management for five, six, and seven years respectively. To accurately measure the effects of organic management, we will devide split plots in three portions, first portion for assessing effects of organic management on reducing tomato soil-borne diseases in 2023, second portion in 2024, and third portion in 2025 (see attached supplemental plot layout). Such field design allows us to assess the impact of a chronosequence of organic farming management on soil's suppressing ability of diseases. The dependent variables for this objective will be disease incidence, disease severity, fruit yield, and fruit weight. We will collect data for all soil-borne diseases detected in susceptible varieties. Disease incidence and severity of root and stem diseases of tomato will be evaluated every two weeks after transplanting. The tomato yield will be assessed at the end of the crop season. The number of fruits and weight of fruits will be recorded. We will analyze the interacting effects of the main plot and split-plots on disease incidence, disease severity, and fruit yield. The statistical analysis will be performed using two-way ANOVA to test whether or not the independent variables have a statistically significant (p<0.05) relationship with the dependent variables.Objective 4. ( Extension and Education) :Lincoln University has served the needs of underserved Missourians since 1866, and its role in education and service to stakeholders throughout the state and the nation has long been recognized. In accordance with the mission of the 1890 Land Grant Extension System, the ultimate goal of Lincoln University Cooperative Extension is "to help diverse audiences with limited resources improve their quality of life through the application of educational and research-based information focused on critical issues and needs". Because our clientele is very diverse to include (but not limited to) beginning, limited resources, and minority farmers, then we use culturally-appropriate approaches to deliver research-based information to our stakeholders. One of the vital aspects of this project is to prepare outstanding future farmers, educators, and researchers in agricultue.This proposal supports the experiential learning of students in organic agriculture. The project director will be working with two certified organic growers in Missouri who have internship programs for high school students.Farm 1: Earth Dance Organic Farm and School https://earthdancefarms.orgFarm 2: Happy Hollow Farm https://www.happyhollowfarm-mo.com/Both farms offer 10-week summer internships to high school students. The program offers apprentices the following:Composting and methods of soil fertility managementCrop planning and rotationsPropagation (both in a greenhouse and direct seeding)Organic pest and disease managementAn introduction to farm equipment use and maintenanceProper harvest and post-harvest handling techniquesSelling and marketing via farmer's markets and through the CSA (community supported Agriculture)How to work effectively as a team player and moreThis project will support internships of two students per farm (for 3 Summers) by means of internship stipend payments. , The involvement of students in hands-on learning activities in the farm will help them to learn and experience using the latest developments in organic farming. The main goal of this project is to prepare the younger generation for a successful transition to the agricultural workforce, which is in alignment with this proposal's goal.

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

Outputs
Target Audience:Organic grower organizations, Small farmers with limited resources, Agronomy faculty, Students majoring in agriculture. Changes/Problems:Extreme heat and drought in the summer of 2023 in central Missouri had a negative effect on our field experiments. What opportunities for training and professional development has the project provided?One graduate student and a post-doctoral fellow were identified and hired. Two minority undergraduate students are hired to assist with research objectives in the field and laboratory analysis of soil samples.? How have the results been disseminated to communities of interest?Two Field days and visits by different community clubs such as Master Gardeners, etc. What do you plan to do during the next reporting period to accomplish the goals?The field experiments will be repeated and better managed to prevent deer and wildlife damage. New organic pesticides will be used to prevent outbreaks of insects.

Impacts
What was accomplished under these goals? Objective 1:In mid-September 2022, the field experiment started at the research plot located at Lincoln University's Busby farm which is a certified organic farm. The plot was divided into two areas; the first area is a long-term cover-cropped area by cereal rye and hairy vetch since 2018, and the second area is the first year for cover crop cultivation. Each area contained six replications of a different cover crop termination method, including the no cover crop bare tilled, cover cropped bare tilled, rotary mowed, and flail mowed. A total of 480 zucchini (Dunja variety), 240 per area were transplanted after cover crop termination during the last week of May 2023. In addition to zucchini, tomato plants were also planted as test crop for investigation of soil disease suppressive capacity. Each area received two different tomato varieties, 60 Luci 2103, a variety less susceptible to soil-borne pathogens, and 60 Skyway F1, a variety more susceptible to soil-borne pathogens. The tomatoes were transplanted into rows allowing for three replicates per cover crop termination method per area. Although plants were irrigated by drip irrigation method, because of severe drought conditions and extreme heat in the central Missouri area during the summer of 2023, we did not have a good yield for Zucchini and tomato plants. Also, it is important to note that almost all the tomatoes harvested were still immature and not yet ripe. In our opinion, the severe drought and hot weather may be the reason for tomatoes not getting ripe. In addition, we encountered problems with insects and wildlife damaging the plants and eating the produce. In general, the results for yield indicated that the area with a history of cover cropping since 2018 produced a significantly higher yield than the area that had just received one year of cover crop. Soil samples were collected in Spring 2023 before cover crop termination and again in early September 2023 and processed. Soil physical, chemical, and health indicator parameters including microbial diversity and enzymatic activities are being measured under each treatment using appropriate methods.Objective 2:Soil samples were collected, and analysis is in progress at the University of Missouri laboratory.Objective 3:. The disease incidence (monocyclic diseases) and disease severity for polycyclic diseases were recorded at weekly intervals in the different treatments under field conditions. For the assessment of disease incidence total number of infected plants was counted among the population irrespective of disease severity. The percent disease incidence was calculated using the following formula, Percent Disease incidence = No. of infected plants X 100 / Total no. of plants assessed.The percentage of disease severity was assessed by recording the percentage of infected tissue over the total crop canopy. The percent disease severity was calculated by using the following formula, Percent Disease Severity = Infected tissue X 100 / Total crop tissue/area.?It was observed that two fungal diseases Alternaria leaf blight caused by (Alternaria solani) and Septoria leaf spot caused by (Septoria lycopersici) were noticed in the trial throughout the cropping season. However, the severity of the disease was low to medium. Damping off caused by (Pythium spp.) and Vascular wilt caused by (Fusarium oxysporumf.sp.lycopersici) were observed in a few plots with low disease incidence during the early and later stages of the crop, respectively. Sun-scorching symptoms were also noticed in almost all the plots after transplanting the seedlings to the main field. In Demo Area-1, Alternaria blight severity varied from a minimum (3.70%) in Bare Tilled Skyway-F1 plots to a maximum of 6.90%) in Control Bare Tilled Luci-2103 plots. In Demo Area-2, minimum disease severity (3.58%) was recorded from Bare Tilled Skyway-F1 treatment to maximum (4.95%) in Rotary Moved Skyway-F1 treatment. There was no significant difference was observed among the treatments, Demo Areas, and varieties due to low disease pressure throughout the cropping season. Maximum Septoria leaf blight severity was observed on Control Bare Tilled Luci-2103 plots and minimum (3.01%) in Bare Tilled Luci-2103 plots. Similarly, in Demo Area-2, maximum disease severity 5.86%) was observed in Control Bare Tilled Luci-2103 plots and minimum (3.22%) Bare Tilled Luci plots. There was no significant difference was recorded between the treatments due to low disease pressure.Damping off disease incidence was observed only in a few plots. The remaining plots were found free from disease. Among the Demo Areas, Area-2 had the maximum disease incidence (5.93%) compared to Area-1 with 0.74% damping off incidence. Demo Area-1 was found free from wilt incidence, while a few plots in Demo Area-2 exhibited the wilt incidence. Only Bare Tilled Luci-2103 plots in Demo Area-2 exhibited 3.70% wilt incidence. Results of damping-off and wilt incidence among the Demo Areas boost our hypothesis of the disease suppressiveness effect of long-term cover cropping.Tomato seedlings exhibited sun scorch injury soon after transplanting to the main field due to high sunlight. However, the seedlings were recovered from injury and symptoms disappeared around three weeks after transplanting.Zucchini crop was affected by different fungal and bacterial diseases during the cropping season. Among the fungal diseases Alternaria blight, bud rot, and damping off, and among the bacterial diseases wilt was a major constraint during the cropping season. In Demo Area-1 Alternaria blight severity among the different treatments varied. Among the Demo Areas, Area-2 exhibited maximum disease severity (9.27%) compared to Demo Area-Damping off disease severity in Demo Area-1 was maximum (3.15%) in Flail Moved plots and minimum (0.19%) in control bare-tilled plots. Similarly, in Demo Area-2 maximum disease incidence (7.41%) was recorded from Flail Moved plots and minimum 0.37%) in control Bare Tilled plots. Among the Demo Areas, Area-2 had a maximum (7.41%) damping-off incidence compared to Demo Area-1 with 3.15% disease incidence.Bud rot disease incidence was observed only during the early stage of flowering. In Demo Area-1 maximum bud rot incidence (2.28%) was recorded in Rotary Moved plots and minimum (1.45%) in Control Bare Tilled plots. In Demo Area-2, maximum disease incidence (3.1%) was recorded from Flail Moved plots and minimum in Rotary Moved plots. The disease incidence level was comparatively higher in Demo Area 2. Disease incidence was noticed during flowering to the final harvest stage of the crop. Wilt incidence was very high during the later stage of the crop, it may be due to infestation of higher populations of cucumber beetle and squash bug. In Demo Area-1 maximum wilt incidence (23.0%) was recorded from Flail Moved plots and minimum (15.33) from Control Bare Tilled plots. Similar results were obtained from Demo Area-2 with a maximum (27%) disease incidence in Flail Moved plots and a minimum (12.33%) in Control Bare Tilled plots. Demo area-2 had more wilt incidence than Demo Area-1.Demo Area 1 exhibited less disease incidence (damping off, bud rot, and wilt) and severity (Alternaria blight) compared to Demo Area 1. These results clearly indicate the positive impact of long-term cover cropping on improving soil health and induction of disease suppressiveness in soil.Objective 4. (Extension and Education) One graduate student and a post-doctoral fellow were identified and hired. Two minority undergraduate students are hired to assist with research objectives in the field and laboratory analysis of soil samples. The outreach activities included field days in June and July 2023 and a visit to the experimental plots by Boys and Girls Club/Master Gardeners in August.

Publications