(AP) -- White radishes are taking root on Tony Luthman's farm, the start of what he hopes will create a welcome mat for the corn he plants in the spring.
With taproots that can grow several feet deep, the carrot-shaped tillage or forage radishes bore holes into the ground, loosening the soil. The radishes capture, store and then release nutrients back into the soil, so they also can reduce the need for fertilizer in the spring.
"Some of our ground around here is kind of a tight clay," Luthman said as he displayed radishes on a bench at his western Ohio farm. "I'm hoping that's where these will come in."

Planting tillage radishes began to take hold a few years ago and appears to be growing in popularity. Researchers recently identified the radishes as a good way to prepare soil for planting, as their main roots are larger than the roots of other fall cover crops such as rye and clover.

The radishes are especially attractive to no-till farmers, who plant without plowing or otherwise turning the soil to enrich it, retain moisture and reduce erosion. For farmers who till, the radishes can reduce how deep they must plow.
The radishes have large green leaves and a long white taproot. They are edible and are used in some Asian dishes, but U.S. farmers use them to soften the soil and don't harvest them. The radishes die in the winter, decay and disappear by spring.
Andy Clark, an agronomist with the U.S. Department of Agriculture, said the radishes appear to break up compacted soil, keep weeds under control, and release nutrients.
"But most researchers and many extension people would say we could still used a little more research," said Clark, who is with the USDA's Sustainable Agriculture Research and Education program. "All of the story is not in yet."
Radish seed sales have doubled in each of the past five years at Steve Groff SEEDS LLC, based in Holtwood, Pa. CEO Steve Groff now sells enough seeds to plant nearly 100,000 acres.
At Mid-Wood Inc. in Bowling Green, Ohio, sales of seeds for radishes and other cover crops have grown over four years from 750 pounds to 12,000 pounds. Radish seeds account for up to 50 percent of the sales.