Filling Some Legacy Shoes in Cover Crop Research

As a youngster, John Pike watched Mike Plumer excavate a small pit in a cornfield not far from his own family farm in southern Illinois. Plumer, at the time, was an Extension agent at the University of Illinois.  “He was there to demonstrate how the fragipan soil common to southern Illinois prevents healthy root growth and negatively impacts crop yields,” John said. “The pit clearly showed corn roots hitting the fragipan but not penetrating it.”

At the time, Plumer hadn’t discovered how annual ryegrass, used as a cover crop, gradually breaks down fragipan and allows deeper root growth. “But even then, before he made that connection, his curiosity and deep conviction in conservation tillage made a big impression on me,” John added.

That field day demonstration stuck with John as he later attended college and followed in Plumer’s footsteps at the U of Illinois, becoming an Extension agent and later a research agronomist for the Department of Crop Sciences, in charge of research station operations in the southern part of the state. “It was such a pleasure to have the opportunity to know Mike as a friend and to work with him professionally, before and after his retirement,” he said.

John’s career with the university focused on soil fertility, nutrient management, and water quality. Cover crop research became a significant part of that work. When the university shut down four of its research stations, John started his own ag consultancy as a research agronomist. And that, he said, led to “a more flexible and comprehensive range of work,” a lot of which involves working closely with researchers from other universities.

“Universities have historically been a major source of innovation for the ag industry,” John continued. “But with cover crop discoveries, it was largely the reverse, with innovation coming from the field and gradually informing the universities to backfill with research that quantified the benefits.”

He went on to explain why. “Research involving cover crops is not always best suited to the small plot design used on most university farms. Further, as it relates to cover crop research specifically, the typical 3-year funding cycle common to many research programs is not long enough to capture the cumulative impacts of a cover crop system.  The use of annual ryegrass as a cover crop in fragipan soils is an example. While short-term benefits become evident quickly, like erosion control and nitrogen recycling, the impacts of ryegrass on fragipan soils are realized only over a longer timeframe; the effect of annual ryegrass on fragipan becomes pronounced between the third and fifth years, when corn crops show significant gains in rooting depth and yield.  So, funding a 3-year research program might discount the true potential and lose out on some of the most remarkable impacts.” 

Given that the cover crop revolution didn’t start on university farms, it’s more understandable why some professors and Extension researchers were reluctant to sign on as early cover crop advocates. In fact, some actively campaigned against annual ryegrass because they feared the cover crop would create more headaches than benefits.   

The reticence of university researchers, however, did not deter farmers like Junior Upton (Springerton, Illinois) and independent thinkers like Mike Plumer. Their on-farm discoveries of annual ryegrass’ benefits in the mid-1990s won early support from Oregon ryegrass seed growers as well as their Ryegrass Commission. A decade of replicated field trials helped determine which annual ryegrass varieties were the most winter hardy and which management practices were most effective for control of cover crops with herbicides. The trials also attracted media attention and thus increased university interest.

“Farmers change their crop management practices only when the economic benefits can be demonstrated,” said John, who has continued to farm his own acres as well. “Telling them about soil health is secondary to economics. So, when they hear from their neighbor or find out for themselves that cover crops can save you money or boost your profits, they pay attention. Annual ryegrass does that by reducing erosion and compaction, while boosting yields, improving water infiltration, and many other things.”

So as Mike Plumer retired, and passed away shortly thereafter, John has tried to continue some of Mike’s projects and maintain relationships with many of his long-time farmer/collaborators.  “I like to think I’m helping to keep the ball rolling,” he explained, “but it’ll take many more people like me to move the ball as far down the field as Mike did.  I’m just glad to make sure his efforts and interests are continued, as we shared the same interests.”

The Ryegrass Commission has hired John to further Plumer’s work, with Junior Upton and many of the other growers Plumer attracted to cover crop usage. One of those happy customers, Illinois farmer Marc Bremer,  has been using annual ryegrass in rotation between cash crops and grazing cattle for 15 years. On grazed pastures, he’s seen corn yields increase to 230 bushels/acre and beans to 80 bu/ac. John’s research will create data on the further reduction of fragipan on that farm over the next five years, comparing grazed and un-grazed fields using annual ryegrass to other acreage tilled in the old “conventional” way without cover crops.  

In addition, John will be following up with the University of Kentucky, as researcher Lloyd Murdoch heads into retirement. John will further Murdoch’s work and provide crucial location assistance to Dr. Claire Phillips, a scientist working with USDA’s Agricultural Research Service in Ames, Iowa. “I’ll be monitoring their test sites in southern Illinois,” John said, “including acreage owned by Junior Upton.” “We’re placing field sensors to track hydrology in soils affected by fragipan and gathering data on soils freed from compaction by using annual ryegrass,” he explained.

“Water management is critical in our region and, really, in most parts of the world as well.  Reducing runoff, soil erosion and related nutrient loss is a major factor in the efficiency of our mostly unirrigated row-cropping systems,” John added. “Employing annual ryegrass as a component of cover crop programs helps to keep soil in place, improve water infiltration rates and significantly increases the rooting depth limited by fragipan soils.  “This USDA-ARS led research has national implications,” he said, “and will help to further quantify the impact of annual ryegrass on fragipan soils and its relationship to the soil’s ability to hold more available moisture.”