Duration: 10/01/2024 to 09/30/2029

Administrative Advisor(s):

NIFA Reps:

Non-Technical Summary

Cover crops are a crucial component of sustainable agroecosystems. Their benefits to soil function, primary cash crop protection (weeds, nematodes, etc.), livestock forage, and greenhouse gas emission reduction are well documented. The Southeastern region of the U.S.A., however, is slower than other regions to adopt cover cropping as a management practice.  Therefore, engaging in research to illuminate pathways to success and extension activities to disseminate new discoveries to farmers is needed to increase adoption. The project outlines four objectives that are the focus of the Southern Cover Crops Council’s (SCCC) research and is aligned with the SCCC’s mission to “facilitate and enhance communication and collaboration among producers, extension, researchers, and other agricultural professionals, and transfer information and technologies to promote the successful adoption and integration of cover crops into southern agriculture systems”.

Statement of Issues and Justification

The Need as Indicated by Stakeholders: The issues requiring attention through cover crop research in the Southern region were identified through formal and informal one-on-one and group meetings with farmers, technical advisors, and other agricultural professionals in the region. The Southern Cover Crops Council (SCCC) is a community of farmers, researchers, extension specialists, industry personnel, and non-governmental organizations. The SCCC developed the initial Hatch project to facilitate the participation in multistate research on cover crops of its members who are located at land-grant universities. To this end, the SCCC established a strategy team tasked with identifying research priorities for region-wide research and establishing goals and objectives for the proposed research. The team systematically elicited critical objectives from members of the SCCC who participated via email or teleconference. These individuals provided four sets of critical research objectives, focusing on row crops, specialty crops, winter and summer cover crops, and grazing. Research objectives in row cropping systems concentrated on three primary themes: nutrient management, pest management, and the effects of cover crops on soil moisture. For specialty crops, key considerations were the effects of cover crops on soil and water quality, including erosion control, soil moisture management, and pest management. Winter cover crop objectives included cover crop management (variety selection, planting and termination timing, and residue management), effects on soil health and quality (moisture retention) and obtaining better information regarding the long-term economic and biophysical benefits of cover crop use. Objectives for summer cover crops were similar but typically more specific to a particular crop or cropping system. Grazing management strategies, including rotational grazing using annuals and mixed species, emerged as specific priorities.

The importance of the work, and what the consequences are if it is not done: The significance of this work and the potential ramifications if left unaddressed are paramount. The identified need, as communicated by stakeholders in the Southern region, underscores the critical issues demanding attention in cover crop research. The SCCC played a pivotal role in establishing research priorities and goals. The decision to undertake this work as a multistate effort is strategic and well-founded. The Southern region's diverse climates, topography, and production systems necessitate a collaborative approach to cover crop research. A multistate endeavor not only accommodates subregional differences but also enhances the research's scope, applicability, and overall quality.  The potential impacts of successfully completing this work are far-reaching. Educational materials, databases, and decision support tools tailored to the southern region will emerge, empowering farmers and ranchers. The enhanced communication platforms facilitated by the SCCC, coupled with peer-to-peer knowledge exchange, will further amplify the positive outcomes. The collaborative networks forged through this multistate project are poised to significantly expand the successful implementation of cover crops across the region.

Technical feasibility of the research: A key strength of this multistate project lies in the commitment of SCCC members to offer guidance and oversight through a dedicated SCCC Board standing committee. Leveraging the active involvement of SCCC members in cover crop research within their respective states, the project taps into their knowledge, enriching the existing expertise in cover crops and utilizing the communication and governing protocols established by the SCCC. With voluntary membership reflecting a diverse community of experts, including farmers, extension and outreach specialists, cover crop seed industry staff, and USDA-NRCS personnel, the research benefits from real-world perspectives that play a vital role in shaping its direction.

The advantages for doing the work as a multistate effort: A major goal of the SCCC is to promote natural resource conservation through the use of cover crops that increase farm profitability and environmental stewardship by increasing the knowledge and skills of farmers and ranchers. Coordinated, multistate research is regarded as a key component that will contribute to achieving this goal. The southern region encompasses a range of climates, topography, soil types, and production systems. These differences can influence cover crop adaptability and contribute to the site-specific performance typical with cover crops. The establishment of a multistate project provides a mechanism and framework to build the research and outreach networks that will ensure coordinated research and associated extension provide farmers and ranchers with the knowledge and technology that will lead to favorable outcomes and impacts. A multistate approach will allow the development of recommendations and decision aids that adjust for subregional differences and peculiarities. The multistate collaborations fostered will improve the likelihood of successfully obtaining research funding from grant programs that encourage a multistate approach.

While there may be variations in equipment for planting, irrigation, data collection, and termination across locations—a potential limitation—it also presents an advantage. The diversity in available equipment allows for insights into different approaches employed by farmers in implementing and terminating cover crops. Embracing a multistate approach facilitates the engagement of scientists with complementary expertise, spanning breeding, soil microbiology, and economics. This broadens the research's scope, increasing its extent, applicability, and overall quality of results. In addition to the strengths highlighted, it's crucial to emphasize the proactive approach toward standardizing crop management and data collection and analysis methods across locations. This strategic initiative serves a dual purpose: first, it showcases cover crop management practices that align with local and typical farmer approaches, thereby lowering barriers to adoption. Second, it establishes a foundation for generating robust evidence by promoting consistency in results across various locations and years, reinforcing hypotheses when similarities emerge. This commitment to standardization not only enhances the practicality of implementing cover crops but also strengthens the scientific validity of the research outcomes.

Likely impacts from successfully completing the work: The research will result in increased cover crop options for the southern region and improved knowledge about how, where, and when cover crops should be used to optimize benefits and minimize tradeoffs. Research results will contribute to the development of educational materials and databases, and the creation of new decision tools or modification of existing tools with direct applicability to the southern region. Related extension and outreach will involve improved SCCC platforms for communication with farmers and ranchers and enhanced peer-to-peer knowledge exchange among farmers and ranchers. The integrated networks of farmers, university researchers, USDA ARS researchers, and USDA NRCS personnel and researchers fostered by the multistate project and facilitated by the SCCC will contribute to an expansion in acreage on which cover crops are successfully implemented.

Related, Current and Previous Work

Research about the use of cover crops has been rapidly increasing in the Southern region in response to stakeholder-identified needs for better guidance on management. Research funded for cover crops wholly or in part identified in CRIS includes 91 active projects (many are multistate with multiple institutional entries).  This number increased from only 28 in 2019, representing more total institutional entries than for other regions. It is a clear indication of a high degree of effective collaborative development in the Southeastern Region over the intervening time-period.

 

Cover crops were historically relegated to a secondary emphasis in past research, rather than the focus.  This limited the range of treatments employed and the ability to understand the interactions among cover crops, target crops, weeds, and pests. Component research, such as effects of cover crops on soil nitrogen, carbon cycling, or emission of heat trapping gases continues to advance in the region. However, comprehensive research that focuses explicitly on the crop-cover crop-soil-pest system remains under-developed. Two highly related bodies of research have emerged in the past decade, the role of cover crops in soil health and quality and the complex relationships between cover crops and the management of weeds, pests, and pathogens.

Objectives

1. Evaluate a common set of soil health indices (biological, chemical, and physical) that are applicable (i.e., accessible and affordable to producers) and meaningful across crop and cover crop combinations throughout the region’s diverse set of climate-edaphic conditions to develop a region-wide system of recommended practices.
   
2. Select and evaluate summer and winter cover crop germplasm for regional adaptability and determine the appropriate timing of planting, seeding rates, utilization of cover crop goods (includes grazing), and termination to optimize benefits without adversely affecting cash crop cycles.
   
3. Assess the influence of cover crops on soil properties that affect cash crop outcomes.
   
4. 4. Characterize cover crop efficacy for enhancing cropping system resilience to weeds, pests, and plant pathogens.
   

Methods

Objective 1: Evaluate a common set of soil health indices (biological, chemical, and physical) that are applicable and meaningful across crop and cover crop combinations throughout the region to develop a region-wide system of recommended practices.

Using prior research experience and the cover crop primary literature, participants will examine the appropriateness of soil health indices that are used or proposed for assessing the effectiveness of cover crop utilization across the soils and climatic conditions of the Southeastern region. Identification of appropriate indicators will involve substantial on-farm collaboration and applied and demonstration research.  The resulting indices selected will therefore have relevance to important farmer stakeholders, but also to other stakeholders in the soil health space, including soil and environmental analysis laboratories, USDA-NRCS, and university educators and their students.

 

Objective 2: Select and evaluate summer and winter cover crop germplasm for regional adaptability and determine the appropriate timing of planting, utilization of cover crop goods (includes grazing), and termination to optimize benefits without adversely affecting cash crop cycles.

This objective will include breeding and selection collaborations for new cover crop germplasm with adaptability to the southern region. Additionally, other researchers will evaluate new and existing summer and winter cover crop germplasm in multiple locations in each state to characterize cover crop species, varieties, and germplasm lines in order to assess productivity and adaptability. This objective will also involve the estimation of cover crop nutrient and water requirements in addition to their growth potential. Studies will examine planting and termination dates to determine what dates give optimal results for the region and whether cover crop benefits can be derived from the use of suboptimal dates since . For cover crops that also yield a commercial good such as forage for grazing animals, studies will determine which strategies allow for effectively utilizing the commercial good while still accruing benefits from the cover crop. The data to be collected will be used for developing site-specific recommendations for use of cover crop monocultures and mixtures that provide more predictable cover crop performance and outcomes. Research will be pursued to characterize the social issues related to successes or failures when adopting cover crop technology and develop better models for pathways to success.

 

Objective 3: Assess the influence of cover crops on soil properties that affect cash crop outcomes.

A clearer understanding of how cover crops can influence nutrient and water use efficiency of the cash crops is needed. Given the region’s diverse climate and soil conditions, specific questions might be more relevant in some areas, and those areas will be targeted to address these questions. For example, soil moisture is an issue in some parts of the region (e.g. Texas High Plains for row crops) but less so in others. As a result, cover crops will be evaluated as monocultures and mixtures within cropping systems using different techniques depending on location and questions addressed. In regions where row crops are planted in raised beds, different planting techniques of cover crops will be evaluated.

Similarly, there is a need to develop data-based recommendations for the use of cover crops as catch crops to protect ground and surface waters from nutrient loading. For example, the efficacy of different cover crops as catch crops for scavenging residual nutrients from previous cash crops and their ability to limit leaching and runoff of nutrients to ground and surface waters remains poorly known. Cover crops also differ in their residue decomposition dynamics and nutrient release patterns and capacities, and subsequently the percentage of nutrients from a preceding cover crop that are utilized by succeeding cash crops, which are all influenced by factors such as climate, tillage system, soil type, and soil microorganisms. Leveraging past and current research on this topic, the effects of cover crop types and management strategies on nutrient cycling and soil fertility (e.g., residue decomposition, nutrient availability, soil organic matter, cation exchange capacity) will be evaluated. The long-term effects of cover crop use on soil biology and soil health will also be documented. 

 

Objective 4: Characterize cover crop efficacy for enhancing cropping system resilience to weeds, pests, and plant pathogens.

Intercropping cover crops as living mulches and adding cover crops to crop rotations during the off-season can be utilized for suppression of weeds, pests, and pathogens. Since cover crop species and varieties can vary in their ability to provide such protection, further research is needed to document the utility of regionally adapted cover crops for crop protection. Conversely, there is also need for greater documentation on cover crop susceptibility to pests and disease so that recommendations can be refined, and farmer use of cover crops does not create or exacerbate pest and disease problems. Horticultural crops within the region tend to have a high dependence on pesticide use and may benefit from identifying cover crops that can contribute to cropping systems that are more resilient to weeds, arthropod pests, and pathogens. The following types of studies are anticipated:

1. Assessing within cover crop species host status against plant pathogenic nematodes.
2. Characterizing the effects of cover crop residues on plant-parasitic nematodes.
3. Optimizing cover crop use for managing weeds.
4. Developing recommendations for cover crop and living mulch use for tropical agroecosystems.
5. Evaluating cover crop and living mulch effects on beneficial and pest arthropods.
6. Determining the influence of cover crops on soil-borne disease and soil suppressiveness.

Measurement of Progress and Results

Outputs

• A common set of biological, chemical, and physical measures and indicators adopted for the southern region to evaluate cover crop performance and document the benefits of cover crop use. The measures of benefits and performance of cover crops will take into account agroecosystem functions such as carbon sequestration, nutrient retention, biomass production, weed suppression, and nitrogen fixation. Trade-offs or the net outcome of cover crop use will be important aspects for dissemination via extension and outreach to farmer/grower clientele and the general public.
• New recommendations of cover crop germplasm adapted to the southern region.
• Database of information on cover crops adapted to the southern region including recommended planting and termination dates for different cropping systems and approaches to optimize the harvest of commercial goods from cover crops/retention of the environmental benefits.
• Information to update and expand decision support tools for selecting cover crops based on criteria such as subregion, soil type, cropping system, and required ecosystem services. These tools, such as the Cover Crop Species Selector (https://covercrop-selector.org/) will promote cover crop use throughout the region.
• Documentation of barriers to adoption of cover crops in the southern region and recommendations for pathways to success that minimize barriers.

Outcomes or Projected Impacts

• More farmers using cover crops in the southern region.
• Increased acreage of land planted with cover crops
• Improved nutrient and water use efficiency.
• Reduced need for off-farm inputs such as fertilizer and pesticides leading to improved farm economics.
• Improved environmental conditions related to ecosystem services that accrue from cover crop use.
• Improved ability to relate soil health indices to on-farm outcomes in the region.

Milestones

(2024):Renewal proposal submitted and integration of Hatch S1085 with SCCC research committee achieved. Establish working groups for each objective. Write and submit grant proposals.

(2025):Publish evaluation of soil health indices identified in Objective 1. Pursue funded research on Objectives 1-4. Continue to develop and refine decision support tools. Share progress at SCCC annual meetings, annual reports, and other opportunities as they arise.

(2026):Second year of funded research on Objectives 1-4. Continue to develop and refine decision support tools. Share progress at SCCC annual meetings, annual reports, and other opportunities as they arise.

(2027):Third year of funded research on Objectives 1-4. Continue to develop and refine decision support tools. Share progress at SCCC annual meetings, annual reports, and other opportunities as they arise.

(2028):Publication of peer review and extension articles. Summarize clientele utilization of decision support tools over the intervening period of the project. Determine next research priorities. Write and submit continuing multistate project. Summarize all activities at annual SCCC meeting and through annual reports and other opportunities.

Projected Participation

View Appendix E: Participation

Outreach Plan

For each objective, participants will coordinate and communicate about research activities, data analysis, presentations, and publications using a videoconferencing platform. Additionally, during an annual meeting, investigators will present an oral report as well as provide a written report for collation into an annual report. Multistate outreach and communication through the SCCC will be facilitated by the Outreach and Communication standing committee. Researchers and extension specialists will coordinate to develop/modify SCCC decision support tools. Results will be communicated via the SCCC website and presented at field days, workshops, and scientific meetings. Social media will be used to communicate ongoing research progress, when applicable (e.g., using platforms allowed by each participant’s institution).

Organization/Governance

Current governance includes a Chair, a Chair-elect, and a Secretary. The existing project governance will be brought forward. Each successive year, a secretary will be elected by the SCCC research committee to serve in that role for one year, transitioning the following year to Chair-Elect, and the year after that to Chair. In this way, each officer serves a total of three years through successively elevated roles. The initial Administrative Advisor will be Dr. John Davis of University of Florida IFAS.

Literature Cited

Attachments

Land Grant Participating States/Institutions

Non Land Grant Participating States/Institutions