Resources that Help Sustainable-Organic Vegetable Growers Select, Use, and Evaluate Microbe-containing Crop Stimulants (MCCSs) More Effectively

Project Overview

Project Type: Research and Education
Funds awarded in 2016: $198,842.00
Projected End Date: 01/15/2021
Grant Recipient: Ohio State University
Region: North Central
State: Ohio
Project Coordinator:
Matthew Kleinhenz
The Ohio State University-OARDC

Information Products


  • Vegetables: carrots, cucurbits, greens (leafy), greens (lettuces), tomatoes


  • Crop Production: biological inoculants, organic fertilizers
  • Education and Training: demonstration, extension, farmer to farmer, focus group, mentoring, networking, on-farm/ranch research, participatory research, workshop
  • Production Systems: transitioning to organic

    Proposal abstract:

    Plant-associated microbes can significantly impact crop production. Many microbes are now included as leading components of microbe-containing crop stimulants (MCCSs) advertised to enhance soil and crop health, accelerate soil nutrient cycling, and improve crop quality, among other benefits. Therefore, MCCSs appeal to ever-greater numbers of sustainable-organic farmers (SOFs). The challenge, however, is that MCCSs are numerous, diverse, and often expensive to apply. Also, most MCCS labels offer little help when selecting or using products. Worse, objective, user-oriented, and research-based resources used by SOFs and their advisors rarely include information on MCCSs. SOFs and their advisors would clearly benefit from resources for selecting, using, and evaluating the benefits of MCCSs. For MCCSs, we have: a) assessed use by growers; b) synthesized available information and incorporated it into widely-available, user-friendly, and enthusiastically-received resources; and c) completed pilot on-station and on-farm studies. Evidence points to an urgent need to expand and strengthen this process, thereby preparing SOFs and their advisors to address significant and recurring questions about MCCSs now and going forward. We will partner with SOFs, organizations, MCCS manufacturers, and extension-research colleagues to develop technically rigorous, consensus-based, and user-oriented educational and decision-making resources. We will demonstrate a replicable process for evaluating MCCSs that minimizes guess-work in selecting and using them and evaluating their economic benefits. Experiments will address questions about inoculant-crop-production setting combinations and inoculation timing and rate. Team and grower-chosen MCCSs (single-species, single-genus multi-species, multi-genera) will be applied to butternut squash, carrot, lettuce, spinach, and tomato grown on sustainable-organic farms and at the Ohio Agricultural Research and Development Center. Inoculation timing and rate treatments will be tested in individual experiments during the crop cycle (e.g., before seeding, during transplant production, after transplanting). Similar experiments will be completed in open fields, and under low-, mid- and high tunnels. Microbial colonization and crop development and productivity will be tracked from seeding through harvest; crop yields and MCCS costs will be included in economic models. Farmer experiences with MCCSs will also be documented and summarized. Material, digital, and human networking resources will insure that new research-based information is widely available in user-friendly formats. Overall, we will improve farmers’ immediate capacities to sensibly and reliably integrate MCCSs into their toolboxes while also fostering durable gains in farmers’ on-farm research skills and in resources educators can apply in serving SOFs.

    Project objectives from proposal:

    We will work to limit the very significant challenges SOFs face in making the best use of MCCSs by:
    1) Using crop and financial metrics to comprehensively evaluate MCCSs at The OSU and on farms;
    2) Expanding and strengthening a growing network of farmers, MCCS manufacturers, scientists, educators, and
    consultants engaged in evaluating and reporting on MCCS performance; and
    3) Establishing, sharing, and helping stakeholders implement core components of user-centered guidelines for the
    best practical use of MCCSs on sustainable-organic farms.

    We will achieve two goals by project end.

    First, we will have described the effects of numerous MCCSs – for the
    first time – objectively, for a wide audience, and specifically to address growers’ concerns.

    Second, by establishing teams of trained evaluators and teachers representing the best of farmer and extension-scientist capacities, we will have prepared SOFs and others to select, use, and evaluate these products much more reliably in the future, with special emphasis on cost-effectiveness.

    Our primary research objective is to use crop and financial metrics to comprehensively evaluate MCCSs at The OSU and on farms. Increasing SOF access to high quality, high priority, and ready-to-use information from these evaluations will help them earn greater returns on their investments in MCCSs. Further, a network of farmers, researchers, manufacturers, and others will join in creating, disseminating, and helping stakeholders use MCCSs more reliably. We propose to test six products differing in manufacturer, composition, crop host, and the extent to which we and growers have experimented with/used them.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.