By CELESTE BAUMGARTNER
Ohio Correspondent

ANNA, Ohio — Tony Luthman planted 39 acres of oilseed radishes on his farm, hoping they will ease the way for the spring corn crop.
“Brassicas (radishes are part of the Brassica family) in general are beneficial in that they do help loosen up the soil because of that root structure,” said Roger Bender, Ohio State University agricultural agent in Shelby County. “Because of their nature, when they grow they store nutrients in that root structure.”

In addition to recycling soil nutrients the radishes will suppress weeds and pathogens, produce large amounts of biomass, reduce soil erosion and break up soil compaction, according to an OSU fact sheet cited by Bender.

The soil in Luthman’s area is comprised of tough clay soil and the field in which he planted the radishes has highly erodible ratings, Luthman said.

“These radishes looked like they would be something that could break up possible compaction layers or loosen the soil,” said Luthman, who planted the radishes in wheat stubble. “This is the first year that I have used them; the way they look right now, I’ll continue.”

He planted the radishes on Aug. 12. It was dry and stayed that way for a while; he figured he had about an 80 percent stand.
Yet by early October, after some rain, the radishes had about 18 inches of lush, leafy top growth and the roots were going 6-10 inches down in the ground, he said.

“We had sprayed the weeds that were coming up in the wheat stubble beforehand,” Luthman said. “We put down three tons of chicken manure before we sowed the seeds.”

Applying poultry or liquid manure before planting the radish seeds is the best way to ensure maximum growth, especially if that is followed by sufficient rainfall, Bender said.

Luthman planted 8-10 pounds of seed to the acre with a Great Plains drill. He chose the oilseed radishes over forage because the forage radishes tend to have more top growth.

He was more interested in preserving the nutrients in the soil.
“The radishes scavenge nutrients – especially nitrogen – and hold them for the next crop,” Luthman said. “That was another reason we did it.”

“It wouldn’t make any sense to do it for wheat because you wouldn’t keep it over the winter, or for soybeans because they’re a legume (which manufactures its own nitrogen),” Bender said. “But it makes sense for corn.”

Three days below 20 degrees are said to kill the radishes, Luthman said. “They’ll deteriorate by next spring and we’re hoping to go in and no-till corn into this field next spring,” he added.

The radishes are edible and are used in some Asian dishes. Luthman tasted one and said it had a little more “bite” than a typical garden radish.

Also, the radishes work best after a wheat crop because they can be planted early; they grow fast but not overnight, and an early frost could kill tender plants, Bender said.

For more information refer to www.ohioline.osu.edu online; click on “Fact Sheets,” then “Sustainable Agriculture Series.”