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Put a crimp in green manure

No matter if a farm is organic or traditional, a grower can probably use another idea for improving the amount of nitrogen available to the crop. University of Manitoba researchers are considering a piece of equipment that can improve nutrition and reduce the need for tillage.

The crimper was built from Rodale Institute plans. Photos courtesy of the University of Manitoba.

Called a “crimper/roller,” the process involves rolling the crop to crimp the stems, essentially killing the plant and creating green manure. The next crop is seeded into the dying crop, reaping the benefits of the green manure and reduced soil disturbance. “This is not new technology because it is used in the tropics, but it is new to Canada,” says Dr. Martin Entz, a plant scientist in the university’s Faculty of Agricultural and Food Sciences. “We built our roller in Manitoba from plans supplied by the Rodale Institute in Pennsylvania.”

A master’s student working with Dr. Entz joined the research in its second year and she reports the roller worked well at the university’s research farms in Carman, Manitoba, and Oxbow, Saskatchewan. According to Iris Vaisman, the team is still learning how to use the roller, but already she sees application in conventional tillage systems as well as reduced tillage. “We’re learning if this equipment can be used effectively and how,” Vaisman says. “In the no-till system it appeared wheat seeded into peas and oats that were rolled using the roller/crimper was delayed. However, it seemed to catch up later in the season.”

It is still early in the testing process and the team is not ready to offer recommendations on use. “By crimping the stems of the plants you are trying to kill the residue anchored in the soil,” Dr. Entz explains. “You don’t want to cut the stems, you just want to crack them at 20 cm increments so the plant will die but remain lying on the surface.”    The new crop is then easily seeded into the crimped crop.

The crimper kills the crop but leaves the residue on the soil surface.

Dr. Entz explains the effectiveness of the equipment is in the design. He says the blades are a chevron shape on a roller that hits the ground at different intervals. “It’s all designed to accomplish crimping to kill the plant and allow the cell nutrition in the plant to leach into the soil.”

Currently there is no commercial production of this equipment, but designs enabling growers to build their own crimper are available from the Rodale Institute website (www.rodaleinstitute.org/notill_plans).Dr. Entz says the university’s research version cost around $8,000 to build, but a larger 20-foot version could cost as much as $30,000 to construct. If a grower is already considering a move to tillage reduction and is planning the purchase of new equipment, this might be a viable option. “This process could fit into a conventional tillage system, particularly if green manure is being grown,” continues Vaisman. “This could provide an option over tilling the green manure into the soil. When a crop is rolled in this manner, a ground cover remains that helps to maintain soil moisture.”

Dr. Entz says the crimper also can assist in weed control because the cover can replace the tillage normally used to reduce annual weeds. “This is a new way to look at weed control because the mulch created from the crimping process smothers the weeds,” he explains.

Both Vaisman and Dr. Entz say that research will continue to refine the way the equipment is used and to prove its benefits. “This equipment is still experimental in Canada,” Dr. Entz admits, “but with the rising cost of fuel, this might be a viable option for many reasons in all tillage systems.”

As work continues in Canada, organic growers in United States continue to post photos and testimonials on the value of crimper/rollers on the Rodale Institute website. Dr. Entz believes it is a tool that Canadian growers will soon embrace as well, particularly if the early positive research results are proven to be the real deal.