February 2011
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Cover Crops Boost Yields for Giles County Farmer


Giles County farmer Bart McCormick turns to cover crops to boost his yields.


Radishes Promise Greener Way to Farm

Cover crops are nothing new. In fact, Zollie McCormick first learned about their benefits during the 1930s from his local chapter of the Future Farmers of America (FFA).

His FFA instructor in Colbert County encouraged students to use vetch and other cover crops as a means of soil conservation.

Zollie moved his family to Tennessee in 1963 and began farming full-time in 1965. Now age 86, Zollie still farms near Elkton, TN.

Zollie’s son, Bart, recalled when the old way of thinking about things began to come to light.


Larry Dickey examines an oilseed radish planted on the farm of Bart McCormick in Giles County, TN. Dickey works as an outside salesman for the Giles County Co-op in Pulaski. The crop of oilseed radishes could be mistaken for a field of turnip greens. This radish is actually a member of the mustard family.

"In the early 1980s, farming was tough," Bart said. "My dad started showing us the benefits of cover crops—how they enhanced your ability to produce."

At first, the notion was met with resistance, as is the usually case. Cover crops can be difficult to remove from fields. Producers must commit labor and resources normally reserved for cash crops to getting cover crops out of the fields.

The problem had an "easy" solution. No-till cover crops provide all the benefits without the added difficulties and expenses of removing them from the fields.

Cost-effective Way to Boost Yields

This year, Bart said the mean-cost for him to put in cover crops on virtually his entire farm of 4,000 acres was $32 per acre. That cost included seed, labor, fuel and machinery. While not all of his cover crops are no-till, much of them are.

Bart, 52, recalled a few years back when he didn’t use a chopper on the combine harvesting soybeans. The spreader dispersed the chaff in clumps in the field. When it came time that fall to harvest the corn planted behind those soybeans, a large difference was evident in the yield.

"It was phenomenal how much better the corn was that was planted through a clump of residue than it was on the bare ground," Bart said. "Little things over the years convince you this absolutely has an effect."

In 2009, Bart bought seed and had the drill ready to go. He had intentions of planting his entire 4,000 acre farm in various cover crops.

"That was the year we shelled corn in the rain," Bart recalled. "We were only able to plant about 80 acres in cover that year."

On April 7, 2010, Bart planted corn following a no-till cover crop on that same 80 acres. Once harvested, that corn yielded 195 bushels per acre. The yield for his corn not planted behind a cover crop was around 130 bushels per acre.

Bart decided right then that cover crops were the way to go. He began looking at covers outside of his usual plantings of rye and vetch.

This year, all but a couple dozen acres are planted with cover crops. Those not planted needed tile and drainage work done.

Oilseed radishes promise to improve soil quality.


Oilseed Radish: Nutrient Scavenger

After much research, Bart decided to supplement his cover crop pool with Daikon oilseed radishes.

"The radishes are a nutrient scavenger, they will scavenge nitrogen from as much as six feet deep," said Bart. "Not only nitrogen, but other nutrients as well."

Besides the added nutrients, cover crops can also reduce soil temperature by as much as 20 degrees, said Bart.

The benefits are numerous. Cover crops help create an ecosystem.

Some of the benefits are subterranean insects, microbes and an increase in organic matter.

"It’s an inexpensive way to get Mother Nature to work with you," Bart said. "We do believe in it."

As most producers know, getting a cover crop out of the field is the main deterrent to planting one. Freezing temperatures of about 20o will kill the radishes, making way for cash crops to be planted.


The Daikon variety of oilseed radish produces a root that can reach a foot in length. This root can help draw nutrients from deep in the soil and deposit them into a nutrient-rich zone where they can be absorbed by cash crops.

According to a publication (SAG-5-08) by Ohio State University, the "oilseed radish is a unique cover crop farmers are planting to improve their soil quality for economic crop production. It has the ability to recycle soil nutrients, suppress weeds and pathogens, break up compaction, reduce soil erosion and produce large amounts of biomass."

Bart and his wife, Stacy, farm with his brother, Terry, and nephew, James, near Wales.

They employ 10 to 15 workers, depending on the season.

His farm depends of the Giles County (TN) Co-op for chemicals, seed corn and fertilizer.

Celena Cole Lann is the branch manager of the Giles County Co-op in Pulaski, TN. Larry Dickey works as an outside salesman.

More Information

For more information about oilseed radishes, visit: ohioline.osu.edu/sag-fact/pdf/Oilseed_Radish.pdf

Additional questions can be answered by contacting your local Extension agent.

Susie Sims is a freelance writer from Haleyville.