Tillage radishes extend forage grazing
Livestock producers searching for ways to increase fall forage and suppress weeds may want to try planting tillage radishes.
“This is a fun crop,” said Kelly Nelson during the recent Missouri Livestock Symposium. Nelson was impressed with the amount of forage aboveground and the soil aeration belowground that the radish provided. “I see tremendous potential with this crop,” he added, “but planting date makes the difference.”
In 2011, he designed a trial to look at how tillage radishes performed with different planting dates, tillage methods and grazing practices. He found that early planting caused more fall tonnage and less spring weeds.
Nelson planted tillage radishes starting Sept. 1, 2011, at the University of Missouri Greenley Research Center near Novelty. His last planting date was Sept. 26, 2011.
Top ground yields for the Sept. 1 planting date were 2 tons per acre. Belowground, tuber yield was also 2 tons per acre. “That is dry weight,” Nelson explained. “Take that times 10 to get its fresh weight.”
By Sept. 26, top ground forage yield was one-third of a ton per acre and tuber yield was one-tenth of a ton per acre.
“The key is to get out and plant [tillage radishes] early,” he said. “That will help maximize your forage production and give you time to graze.”
Nelson repeated the study in 2012 and started earlier — in August. The plots saw similar yield results, showing that earlier radishes (planted Aug. 1) had greater top-side and tuber growth.
Nelson used no-till and conventional-till practices in his field trial, and saw no difference in yield. “I think it will depend on your situation as to what works best in your operation,” he said. “The good news is that tillage radishes seem to work in both.”
However, for crop farmers, Nelson said there may be an added “tillage” benefit in the spring. Last May, he headed out to plant corn in a no-till plot where radishes were planted the prior fall. “I see why they call it tillage radishes,” he said. “It looked like I tilled the ground. It looked like I ran a field cultivator across the ground.”
Nelson found radishes do a good job of preparing the soil for the next growing season, reducing the need for tillage, and for chemicals for weed control.
From the early planting date of Sept. 1, there was a 77% reduction in weeds in fields planted with radishes, compared to the control fields without radishes. That compared to the just 5% reduction seen with the Sept. 26 planting dates.
He found the same weed-suppression rates in grazed and non-grazed trials. “Tillage radishes are very aggressive and competitive up front,” Nelson explained. The radishes grew early and inhibited other weed growth around them. Ultimately, Nelson found weed suppression was an “added benefit” to tillage radishes.
RADICAL RADISHES: Kelly Nelson, an MU research agronomist, is finding soil, weed and forage benefits in tillage radishes in northern Missouri.
EARLY GROWTH: Tillage radishes planted in early August 2012 saw the greatest aboveground forage growth, as well as belowground tuber growth. Feed and soil benefits both decreased when planted later in the season.
This article published in the January, 2013 editionof MISSOURI RURALIST.