This page provides overviews of several important aspects of organic agriculture production such as roller crimping, weed control, and disease management. These sections can be navigated using the "Jump to a Section" feature below or feel free to scroll through the page.
If you are just getting into organic agriculture, you may find this free Guide for Organic Crop Producers from ATTRA helpful, which is intended to lead farmers through the organic certification process.
Roller crimping is a technique used to terminate cover crops ahead of no-till planting a cash crop. It is a high management system that requires an adaptive management approach. Roller crimping is most commonly adapted to terminating cereal rye cover crop ahead of no-till soybean production in US cropping systems. Visit our full guide to roller crimping here or continue reading below.
Roller crimping may be right for you if you are...
- An experienced no-tiller
- Growing later planted soybeans
- Willing to plant green or into high residue
- Comfortable with cereal rye cover crop potentially setting viable seed (for those raising small grain crops, this is a major risk to be managed or completely avoided)
- A farmer looking to reduce tillage and/or herbicide use
The Purdue Extension Organic Agriculture Program is proud to offer a roller crimper available for lending for any operation. To learn more about our roller crimper, contact Michael O'Donnell.
Quick Guide to Roller Crimping for Organic and Non-Organic Operations
From the New Ag Network's "Organic Weed Control" fact sheet written by Dale Mutch.
Weeds are the No. 1 concern for field crop organic farmers and pose important problems for vegetable and fruit organic farmers. This is because weeds can dramatically reduce crop yield if they are not managed and controlled. Specific weeds may also provide alternative hosts for insects and pathogens, as well as interfere with harvest either by interfering with machinery or through crop contamination. Organic farmers must use multiple tactics to manage weeds because they cannot use synthetic herbicides, and existing organically acceptable herbicides are costly and primarily limited to burndown activity. For more information see the “Integrated Weed Management” books in the reference section.
Know your weeds
As they say, “Know your enemy.” Organic farmers need to pay close attention to what types of weeds are in their fields and how they grow. Know weed life cycles. Are they annual, perennial or biennial weeds? Will the weeds germinate early or mid-summer? How deep in the soil will the seeds germinate? How much seed will the weed produce? Do weeds reproduce vegetatively via rhizomes or stolons? An additional question specific to perennial crops is: Which weeds are problems at time of establishment versus post crop/planting establishment?
Care for your soil
The best line of defense is to build healthy soil. A biologically active and diverse soil will reduce weed populations and help crops grow faster. The faster a crop builds a canopy to fill rows and cover the soil, the less impact weeds will have on the crop. Decreasing weed growth dramatically reduces weed seed production. Healthy soils stimulate weed seed decay and can increase weed seed predation. Healthy soil can be built by using cover crops, choosing good crop rotation, applying compost and other organic soil amendments, maintaining appropriate drainage and reducing compaction. Generally, farmers want to keep weeds out of the field for the first four to six weeks of annual crop growth to maximize crop yield potential.
Commonly used strategies
Here are some of the practices used by organic farmers to reduce weed problems:
- If early weed species such as common lambsquarters or smartweed begin growing, consider allowing these weeds to germinate, then kill them with tillage and delay the crop planting, allowing the crop to get ahead of the weeds.
- Increase seeding rates and narrow planting rows to give the desired crop a competitive advantage over weeds.
- Select varieties that will succeed better under organic farming methods.
- For perennial fruit and most vegetable crops, consider using mulches to “smother” weeds. These could consist of wood chips, plastic or fabric weed cloth, living mulches or, in some cases, hay or straw.
Stale seed beds
- Use tillage as a tool to control weeds. Early tillage for seed bed preparation could be moldboard plowing, chisel plowing, field cultivating, rotovating, offset discing or field cultivation. After planting, try rotary hoeing, cultivating or flaming weeds with heat to control weeds.
- Pull, clip and remove weeds when the crops cannot be cultivated. If necessary, hire labor. Since weeds are prolific seed producers, removing these larger weeds can have a positive impact on the weed seed bank in the soil.
This fact sheet has covered the very basics of organic weed control. To the right are some excellent references that can be of further assistance.
- "Flaming as a Method of Weed Control in Organic Farming Systems." MSU Extension bulletin E-3038. Mutch, D., S.A. Thalmann, T.E. Martin and D.G. Baas. 2008. E. Lansing, Mich. http://web2.msue.msu.edu/bulletins/Bulletins/PDF/E3038.pdf
- "Integrated Weed Management: ‘One Year’s Seeding…’” MSU Extension bulletin E-2931. Davis, A., K. Renner, C. Sprague, L. Dyer and D. Mutch. 2005. E. Lansing, Mich. Michigan State University. http://web2.msue.msu.edu/bulletins/
- “Integrated Weed Management: Fine Tuning the System.” MSU Extension bulletin E-3065. Taylor, E., K. Renner, and C. Sprague. 2008. E. Lansing, Mich. Michigan State University. http://web2.msue.msu.edu/bulletins/
- “Organic Field Crop Handbook.” Second edition. Canadian Organic Growers, Box 6408, Station J, Ottawa, Ontario K2A 3Y6. www.cog.ca
- ATTRA. “Field Crops.” https://attra.ncat.org/ 800-346-9140.
- “Organic Weed Control: Cultural and Mechanical Methods.” Howell, M. and K. Martens. Acres. August 2002, Vol. 32, No. 8. www.acresusa.com 800-355-5313.
- “Organic Weed Management: Organic Field Crop Production and Marketing.” Burton, M., R. Weisz, A. York and M. Hamilton. North Carolina State University.
- “Weed Management in Organic Cropping Systems.” Penn State University Extension. Agronomy Facts 64.http://cropsoil.psu.edu/extension/facts/agfacts64.cfm
- SARE. m a. “Steel in the Field: A Farmer’s Guide to Weed Management Tools.”
A certified organic farm can control plant disease by implementing a variety of approaches. Good cultural management is a cornerstone to organic disease control, and includes good sanitation, crop rotation (when possible), keeping plants healthy, and the use of resistant varieties. Fungicides can be used as well, but for organic production, fungicide use is limited to using sulfur, copper, oils and bicarbonates to control plant disease outbreaks. These fungicides have been used for thousands of years, but are not as effective as synthetic fungicides. As a result, organic growers need to spray more often. This can be quite devastating to a farmer’s financial bottom line. As such it is important as an organic farmer to reduce the incidence of disease, maintain resistant varieties of crops/fruits, and build up plant defenses to lower the need for external inputs to control outbreaks.
Purdue University has conducted work on disease-resistant varieties of vegetables and fruits, which can be found on a variety of different websites within the College of Agriculture but predominantly in the Departments of Botany and Plant Pathology and Horticulture. A few can be found at the following links.
- Disease Susceptibility of Common Apple Cultivars
- Managing Scab-Resistant Apples
- Disease-resistant Annual and Perennial Production
- Disease-resistant Annuals and Perennials in the Landscape
- Managing Pests in Home Fruit Plantings
Oftentimes the most important aspect to dealing with disease in organic systems is in the cultural practices of cultivating and growing a crop. Maintaining a healthy soil creates a healthy plants less susceptible to disease.
Rotating your crops helps to diminish disease populations from building up. The following link gives you numerous practices to think about to reduce diseases from becoming problems; Managing Scab-Resistant Apples. And although you are not allowed in a certified organic farm to use chemical fungicides, there are some that are considered organic and can be used. The following link does a good job of explaining that the first step to disease management is identifying what you have and then determining what is allowed within the organic certification system; Using Organic Fungicides. Many PDF files can be found at the following websites that give you more information on how to manage disease in your crops, whether it is an organic or conventional system.
Insects can truly make or break crop systems. Organic farms are home to a more balanced and sustainable community of beneficial insects than conventional ones, and there are quite a few cultural techniques that can improve within-field habitat to encourage natural pest suppression services. Still, herbivorous pests can be devastating, but they can also be managed effectively using Integrated Pest Management (IPM) strategies that promote regular monitoring, and proper pest identification. This will enable thoughtful choices of pest control tools that are the most affordable, specific, effective, and will reduce damage to the insect predator community. We'll provide several resources here to help implement sustainable organic IPM strategies.
The Vegetable Insects And Their Management website produced by Dr. Rick Foster and Purdue’s Entomology Extension contains photos you can use to identify vegetable pests and the types of damage they inflict for specific crops.
Beneficial Insects: Predators and Parasitoids
Dr. Mary Gardiner at the Ohio State University produced an excellent natural enemy field guide. This guide will help to identify predatory insects, and describe the pests they commonly prey on.
This video by Rick Foster and John Obermeyer at Purdue University demonstrates the effectiveness of beneficial insects in controlling insect pests.
The Z-Trap electronic insect trapping device helps growers detect and classify multiple insect pest species in crop fields so growers and crop advisers can be more strategic with pest management programs. Spensa Technologies Inc., a company based in the Purdue Research Park, is developing the device that is now used in five continents. (Photo provided by Purdue Research Foundation)
- Introduction to Organic Grain Production
Michael O’Donnell, Purdue Extension
February 19, 2020
- Managing Large-Scale Organic Transition and Parallel Production Systems
Megan Wallendal, Wallendal Farms
February 20, 2020
- Organic No-Till Research Update - Part 1 and Part 2
Erin Silva, UW-Madison
February 20, 2020
- Assessing Nitrogen Release from Cover Crops and Manure
Dr. Shalamar Armstrong, Purdue University
February 20, 2020
- Building a Sustainable Organic Row-Crop System and Growing High-Yield Organic Corn
Darren Fehr, ScatterSeed Farm
February 20, 2020
- OGRAIN is an educational framework for developing organic grain production in the upper Midwest. Resources include field days, annual intensives, a mentorship program, and more.
- This manual, published by the University of Minnesota, is intended as a guide for organic and transitioning producers in the Upper Midwest to lower risk in their operations
- OMRI supports organic integrity by developing clear information and guidance about materials so that producers know which products are appropriate for organic operations.
- ATTRA is a program developed and managed by the National Center for Appropriate Technology, which provides information and technical assistance to those involved in sustainable agriculture in the U.S.
- Fieldwatch & Driftwatch provides a secure online mapping tool to enhance communications that promote awareness and stewardship activities between crop producers, beekeepers, and pesticide applicators.