VAN WERT, Ohio — Oilseed radish, a type of mustard plant originally developed for oil production, is finding another use in Ohio as a cover crop.
Alan Sundermeier, an Ohio State University Extension specialist in Wood County, said that the plant — similar to sugar beets or turnips — is showing potential as a cover crop to help maintain soil quality, increase fertility and provide a myriad of other benefits during the non-growing season. Sundermeier and other Extension specialists are testing the feasibility of oilseed radish as a cover crop in northwest Ohio and the results, so far, have been positive.
"Oilseed radish has a small seed, so it needs very little moisture — about 1/10th of an inch of rain. We planted the plant at the end of July last year and the stuff never stopped growing," said Sundermeier. Researchers conducted test trials for three years, planting at the end of July after wheat harvest. Canada, and other states such as Michigan, are also testing oilseed radish as a cover crop.
In addition to its rapid growth under dry conditions, other benefits of oilseed radish include: a thick, deep taproot that can break up compacted soils; its lack of winter survival that negates the need for herbicide applications in the spring; and the speculation that it contains allelochemicals, chemicals released during decomposition that help control soil-borne pests and weeds.
Oilseed radish is just one option for growers who are looking to plant cover crops after the harvest of corn, wheat or soybeans. Other types of cover crops include legumes (clover, hairy vetch, winter pea) and grasses (rye, oats, wheat).
"Cover crops are not something that a grower is intending to harvest to add value off the field," said Sundermeier. "Cover crops are meant to benefit the soil by improving water filtration, adding organic matter, improving weed control and encouraging beneficial insects."
For all of the benefits cover crops afford, they do have their drawbacks, noted Sundermeier. Adding another planting does take more management and more time; a cover crop can turn into a weed if not properly managed in the spring; and most cover crops need plenty of moisture to get started.
"It's all about picking the right cover crop for your area and your situation," said Sundermeier. For example, oilseed radish thrives in heavy clay soils, hairy vetch can be a good source of seed, and wheat can add off-field value.
For more information on cover crops, refer to Ohio State University Extension's Fact Sheet AGF-142-99, "Cover Crop Fundamentals," on Ohioline at http://ohioline.osu.edu.