Oregon grass seed growers made their way to Kentucky to participate in a field day showcasing how using annual ryegrass as a cover crop can increase corn and soybean yields in the Southeast and Midwest.

The focus of the Soil Building Field Day, which was held March 13 at Paschall Ag Operations in Murray, Ky., was on the ability of annual ryegrass to break up fragipan, a cement-like layer of soil that inhibits yields on 50 million acres of farmland in large swaths of the Southeast and the Midwest.

Lloyd Murdock, professor emeritus at the University of Kentucky, has been working on breaking up fragipan since 2012, when he assembled a team to address the issue. The team has determined that using annual ryegrass as a cover crop, either alone or in mixes, offers growers their best chance to penetrate and break up the layer, which sits 2 to 3 feet below soil surfaces and can span 2 to 3 feet in width. The layer, which is impenetrable for corn and soybean roots, as well as water and nutrients, can dramatically lower crop yields, particularly in dry years.

Murdock’s team has found that the roots of annual ryegrass, grown extensively as a seed crop in Oregon’s Willamette Valley, penetrate the fragipan, and the species’ root exudates, or chemicals released by the roots, dissolve the soil layer.

The idea of using annual ryegrass to break up fragipan actually dates to the early 2000s when the late Mike Plumer, long-time extension agent at the University of Illinois, suggested southern Illinois farmer Junior Upton try it on his farm. The practice eventually led to dramatic yield improvements on Upton’s farm, which at the time was beset by fragipan. Over time, Upton went from averaging corn yields 15 bushels below the county average to 30 bushels above it.

Murdock took the next step in the evolution of the practice by studying the effects of annual ryegrass on fragipan in the lab, in the greenhouse and in grower fields.

The Soil Building Field Day on March 13 was the second field day that Murdock and his team have conducted showcasing annual ryegrass. The team put on a similar field day in 2018 at the Princeton Research and Extension Center in Princeton, Kent.

The field day, which was subtitled ‘How to Gain 2 Feet of Soil by Dissolving the Fragipan’, included presentations from researchers and growers, who provided testimonials on the benefits they have gained from using annual ryegrass as a cover crop, as well as field demonstrations conducted in two soil pits, one in a field that had been under an annual ryegrass cover crop regime for nine years and one, 150 feet apart, that had never been under annual ryegrass.

The Oregon Ryegrass Growers Seed Commission, as well as Saddle Butte Ag, a forage and cover crop seed producer in Tangent, were among the sponsors of the event. The Oregon contingent that attended the event said they felt it went well.

“I was really impressed with the difference between the two soil pits,” said KC Coon, chair of the Oregon Ryegrass Growers Seed Commission and a seed grower from Brownsville. “It is amazing to see how much better the soil quality was in the pit under the annual ryegrass than in the pit where it had never been used.”

“I liked the fact that it wasn’t a super polished event,” said Orin Nusbaum, a member of the commission and a grower from Monroe. “It was very farmer friendly and included a lot of real-world testimonials from folks that have used annual ryegrass.”

“That went great,” said Bryan Ostlund, administrator of the Ryegrass Commission. “It had good attendance, probably the better part of 100, and it is interesting to see the level of interest and just how this story has kind of evolved. It seems like it is just finally getting a foothold down there.”