What information can you give me on building and using a roller-crimper for cover crops?

J.M.WashingtonAnswer: Thank you for your recent request for information from ATTRA, the National Sustainable Agriculture Information Service. I am pleased to provide you with information and plans for no-till roller-crimpers for cover crops.The mechanical roller-crimper is a tool that “rolls down” and “crimps” the stalks of cover crops for no-till weed suppression. Mechanical suppression of cover crops for no-till production can be accomplished through various kinds of mow-down and rolling/slicing/crimping techniques. These non-chemical methods of killing cover crops are appealing as an alternative to chemical-kill methods which rely on the use of synthetic herbicides. The roller-crimper is a water-filled heavy round drum with protruding blunt metal blades arranged in horizontal, angled, or spiral patterns. Roller-crimpers are most commonly rear-mounted and pulled behind a tractor or team of draft animals, but they can also be front-mounted on a tractor. When the roller-crimper is pulled or pushed through a high biomass cover crop?such as wheat, rye, oats or oilseed radish?the cover crop is flattened and “crimped” by the heavy drum with metal strips. The purpose of the metal strips is to crimp or crush the stems of the cover crop rather than cutting or chopping the stems; this simultaneously prevents re-sprouting and slows down decomposition of the no-till mulch. No-till crops are seeded or transplanted in the same direction of the flattened and crimped cover crop, which slowly senesces and dies out over the course of several weeks, leaving high residue no-till mulch.The drums are designed to be filled with water for added weight. The amount of water added varies depending on the size of the roller as well as the field conditions it will be used on. In other words, different field conditions will require different amounts of added weight. The timing of the roller-crimper field operation is critical to gain effective kill of the cover crop. Cereal-based cover crops should rolled at the “anthesis” (flowering) stage of growth or later?in the milk or soft dough stages of growth, a period which corresponds to the mid-spring planting season shortly after the last frost-free day. Growers can refer to charts published by the Extension Service on the Feekes or Zadoks scale of crop growth to gain a clear understanding when anthesis, milk, and soft dough stages occurs (1?2). The Rodale Institute, Kutztown, PA, is spearheading research on roller-crimper equipment designs and on-farm trials using roll-down, no-till organic production systems. Research at the Rodale Institute finds that the best results are achieved by placing the roller on the front end of the tractor while a no-till seeder is simultaneously located on the back of the tractor. This enables a “one pass” roll-down/no-till planting system. They have found that in an organic no-till system, they do actually have to till once every 5-6 years to reduce weed populations. The Rodale Research Institute has published several noteworthy articles and updates on their roller-crimper research project, including photos which are all located on their web site: http://www.rodaleinstitute.org/introducing_a_cover_crop_roller. This site also contains AutoCAD drawings of their design. Below you will also find the contact information for Buckeye Tractor Company, located in Ohio. Buckeye Tractor Company manufactured the 3-point hitch for front-mounting the roller-crimper for the Rodale Institute. Thus far I am aware of two equipment manufacturers in the United States that supply roller-crimpers: I & J Mfg. in Pennsylvania, and Bigham Brothers Mfg. Co. in Texas (3-5). These roller-crimpers can be custom-made according to any width a farmer might need, based on tractor or draft animal team size, and field layout. In addition, farmers are using various brands of stalk choppers, roller harrows, cultipackers, bed rollers, and land rollers, either factory-made or custom modified, to accomplish the same function of rolling down cover crops for no-till production. Below is a list of resources on the mechanical roller-crimper equipment used in no-till production, including equipment designs and technical specifications. References:1. Wheat Growth Stages and Associated Management (e.g., Feekes scale) Ohio State University Extension http://ohioline.osu.edu/agf-fact/0126.html2. Growth and Development Guide for Spring Wheat (e.g., Zadoks scale) University of Minnesota Extension http://www.extension.umn.edu/distribution/cropsystems/DC2547.html3. Buckeye Tractor Co. P.O. Box 97, 11313 Slabtown Road Columbus Grove, Ohio 45830 419-659-2162 800-526-6791Toll-Free 419-659-2082 Fax buctraco@bright.net http://www.buctraco.com 4. I & J Manufacturing 5302 Amish Road Gap, PA 17527 717-442-9451 717-442-8305 Fax www.croproller.com5. Bigham Brothers, Inc. P.O. Box 3338 Lubbock, Texas 79452 806-745-0384 800-692-4449 Toll-Free 806-745-1082 Fax http://www.bighambrothers.comFurther Resources:1. Bowman, Greg. Date Unknown. Plans for No-Till Roller. Kutztown, PA: The Rodale Institute. Retrieved April 30, 2010. http://www.rodaleinstitute.org/notill_plans This site contains blueprints for building the roller-crimper that was designed at the Rodale Institute.2. Michigan State University Roller /Crimper Research website http://www.covercrops.msu.edu/crimper/about.html The Kellogg Biological Station (KBS) roller/crimper was crafted by station technicians with metal from a salvage yard. It is a 10-foot long, hollow cylinder designed with a small plug on the surface to allow the addition of water for higher or lower weight operations depending on field conditions. The R/C weighs 1500 pounds empty and roughly 2300 pounds when full. Like the Rodale model, the KBS R/C has fins extending down the length of its surface designed to crimp the covers as they are rolled. Site contains schematic illustrations. 3. The Knife Roller (Crimper): An Alternative Kill Method for Cover CropsSoil Quality – Agronomy Technical Note No. 13http://soils.usda.gov/sqi/management/files/sq_atn_13.pdfThis 4-page PDF, an NRCS Technical Note, is of particular interest because it has a technical description of the roller equipment.”Knife rollers are hollow steel drums, generally 2 to 3 feet in diameter and no wider than 6? feet, that adjust to soil surface irregularities. More than one can be pulled side-by-side to achieve greater operating width. Approximately 10 blunt knives are along the length of the drum. These knives are 3 to 4 inches tall and are spaced 7 to 8 inches apart (Derpsch et al., 1991; Grooms, 2002). The blunt knives do not cut or chop the stems of the cover crops but crimp or crush them. The drums generally weigh over 800 pounds when empty and can weigh in excess of 1,700 pounds when filled with water. The water is helpful as the height and amount of biomass increase.”4. New Roller Crimper Concepts for Mechanical Termination of Cover Crops in Conservation Agriculture. 2009. By T.S. Kornecki, A.J. Price, R.L. Raper and F.J. Arriaga. Renewable Agriculture and Food Systems: 24(3); 165-173.http://afrsweb.usda.gov/SP2UserFiles/Place/64200500/csr/ResearchPubs/kornecki/kornecki_09b.pdf Modified Abstract: Rollers crimpers have been used in conservation agriculture to terminate cover crops; however, excessive vibration generated by the original straight-bar roller design has delayed adoption of this technology in the United States. To avoid excessive vibration, producers generally reduce operating speeds that increase the time needed to perform the field operation. The objectives of this research were to identify roller crimper designs that terminated rye cover crops consistently, resulted in soil moisture conservation after use, and minimized vibrations when operated in the field. New roller designs generate less vibration than the original design and can be used safely at higher operating speeds.