Tag Archives: fragipan

Annual Ryegrass – the Germ Seed of Cover Crop Adoption in the US Part 18

The Next Generation of Innovators in Agriculture

“There is no known abatement of fragipan,” said Dr. Phillips Phillips, a researcher with the USDA’s Agriculture Research Service (ARS) in Ames, Iowa. “Until now, that is,” she added. “Annual ryegrass is a good one, because the chemicals in ryegrass roots break down fragipan.”

Phillips and the congressionally-funded ARS are delving deeper into the mystery of why annual ryegrass has this effect on fragipan. She said there are 50 million acres of agricultural crop land impacted by fragipan in the U.S. alone. “And fragipans are a problem around the globe,” she added.

Phillips and colleagues have proposed work to follow that of Lloyd Murdock, who for the past decade has been documenting and testing the effect of annual ryegrass on fragipan in laboratory settings and in the field. Murdock’s research at the University of Kentucky found that a chemical exudate from ryegrass roots is the reason. Specifically, the chemical excretion from annual ryegrass roots systematically changes the chemistry and make-up of that compacted soil, effectively reducing the presence of fragipan. In the following graph, taken from Murdock’s study, you can see how annual ryegrass reduced the depth of fragipan and increased the depth of healthy soil in five locations in two Midwestern states.

Phillips is leading a five-year study on annual ryegrass’ effects and how to augment them. “A key part of our research will quantify how annual ryegrass, used as a cover crop, affects the amount and availability of water in the field,” she said. “By reducing fragipan, we may be improving drainage and thus expanding the window for planting in the springtime,” Phillips added. “And we think that reducing fragipan will make more soil water available during the summer too, by increasing root depth. We want to measure how much more available soil water is present, and whether the crop can put on more leaf area and experience less water stress.”

John Pike, a former University of Illinois ag research manager, will be monitoring the study in Illinois, funded by the Oregon Ryegrass Seed Growers Commission.

“Mike Plumer and other pioneers showed that annual ryegrass can be really useful in Southern Illinois, Missouri, and Kentucky,” Phillips said. “As our weather continues to change, ryegrass could increasingly be seen as a ‘climate adaption tool.’ Specifically,” she explained, “in the Midwest we’re having more rain in the spring, and the rain events are bigger. I hope annual ryegrass’ ability to reduce fragipan will allow more water to be absorbed into the field instead of running off. So, even with more rain, farmers will be able to get into the field in a timely fashion, simply because the water will infiltrate more quickly rather than pooling or creating erosion.”

“Additionally,” Phillips continued, “the month of July in the Midwest is becoming hotter and dryer than in the past. July is when the corn most needs moisture. Annual ryegrass, by helping to create deeper soils may be able to make up for that reduced precipitation.”

Phillips’s colleague, Dr. Dan Olk, will lead complementary studies on how annual ryegrass chemically degrades fragipan. Olk, a biochemist, is an expert on humic products, which are derived from young coal deposits and are thought to enhance plant growth. Hypothetically, humic products used in conjunction with annual ryegrass may have a compounding effect on the decay of fragipan and enhancement of crop health. Phillips and Olk will look at samples of fragipan soil collected from Kentucky and Illinois in different stages of degradation. “We want to find out how the chemistry of fragipan changes at different stages of breaking down, and whether humic products change the rate of fragipan disintegration,” Phillips said.

While Phillips is focused on the science and field work, John Pike will also be sharing the educational aspects of the work with a variety of audience, from field day demonstrations to trade shows. Phillips acknowledged the importance of a team approach to this and other projects. “I’m very thankful to those who are partnering with us in our efforts, like John Pike, the Oregon Ryegrass Commission, and Oregon seed growers, who continue their on the ground support for this work.” She also acknowledged Ryan Hayes, an ARS colleague who works on plant breeding at Oregon State University, where she worked before moving to Iowa in 2020.

Some worry about how the adoption of cover cropping and regenerative agriculture will keep expanding, as a generation of cover crop pioneers like Mike Plumer and Lloyd Murdock retire. It is refreshing to see the next generation of growers and scientists, like Phillips, stepping in to develop the place-specific knowledge necessary to make cover cropping work in a challenging environment where it can have the most benefit.

Annual Ryegrass – the Germ Seed of Cover Crop Adoption in the US – Part 17

 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.” 

The Germ Seed of Cover Cropping in the US – Part 14

The Chemical in Ryegrass that Crumbles Fragipan

The hunch that annual ryegrass use was breaking down the fragipan at Junior Upton’s farm in Illinois was like music to Lloyd Murdock’s ears. The University of Kentucky (UK) research team had begun to experiment with different chemicals in the greenhouse and field where he worked at the University of Kentucky’s Princeton farm and in the lab on the main campus.

While they waited for results on field plots of annual ryegrass they planted that year, the UK research team began working with the plant in controlled lab and greenhouse environments. They created extracts made from annual ryegrass roots, as well as from the foliage. “Naturally cemented fragipan clods were placed in a solution of annual ryegrass extract. Thirty days later the size and distribution of the remaining aggregates were determined. As the binding agent in the fragipan is dissolved by the chemical, the fragipan clod begins to fall apart. The greater the dissolution of the binding agent, the smaller the remaining aggregates.  Ag related chemicals were also tested but it was annual ryegrass that demonstrated the most significant ability to dissolve the cementing agents biding the fragipan particles,” he said.

Lloyd also made numerous trips to visit Junior’s farm in those years, to authenticate what they were experiencing there, and to apply what was being gleaned. “We’ve known, for example, that some plants do not exert much pressure at the root tip. Annual ryegrass roots tips, on the other hand, exert a high amount of pressure,” Lloyd said. “So those roots will seek out a crack or weak spot in the fragipan and break through there. It doesn’t take many roots getting through to make a difference. And when corn roots follow those same channels the following year, they’re getting access to nutrition and moisture below the fragipan,” he added. The combination of plant chemistry and root pressure has a dramatic effect on fragipan.

The UK team did replicated trials in five Kentucky and Indiana sites. Below, Table 1 shows, in controlled studies, annual ryegrass reduced the thickness of fragipan significantly at each site, allowing more soil depth for crops.

Dave Fischer is a beef producer from Indiana, and it is his Debois County farm mentioned in the table above. Fisher has planted annual ryegrass on his farm for the past eight years. “When I visited his farm last year, I found that he had lowered the fragipan depth by 14 inches and had annual ryegrass roots 29 inches deep,” Lloyd said.

“Those results floored me,” said Fisher in a video on the project. “But at the same time, I had noticed that these fields seemed to not dry out as fast compared to what they used to and to neighboring fields. We were hanging in there a lot longer during drought periods,” he said. “I would plant it just because of the forage, but the addition of breaking up the fragipan has just been super.”

“I’m more excited about this research than any other project I’ve worked on in my 45 years at the University of Kentucky,” Lloyd said in a University news article, “because it can help so many people. It is something that farmers can work into their operations now to increase their yields.”

As he prepared to retire once again, Lloyd said he has been grateful for the Oregon Commission, and others, whose support was crucial for the UK team’s work on annual ryegrass research. “And it looks like others who have noticed our work are picking up where we’ve left off,” he said with a smile. “Claire Phillips, who received her PhD from Oregon State University and has been a soil scientist for the USDA in Iowa for six years, as well as Dr. Dan Olk and Dr. Dana Dinnes are interested in continuing the work we began. And, likewise, John Pike, an agronomist at Southern Illinois University, has also expressed interest in helping to further the research of fragipan and to continue promoting the use of annual ryegrass as a cover crop.”

The Germ Seed of Cover Cropping in the US – Part 13

Annual Ryegrass…When “Breaking Up is Hard to Do”

An “aha” moment began this 14-part series, and it’s fitting we end it with another aha moment!

Dr. Lloyd Murdock has spent many of his productive years at the University of Kentucky as a soils and crop specialist. The link in the previous sentence summarizes a decades long effort that has earned Lloyd a well-deserved reputation as one of America’s “pioneers of no-till agriculture.”

“I had retired in 2012,” Lloyd recalled, “but specifically returned part time the following year to focus research on how to eliminate, or at least reduce, a deep layer of cemented soil called fragipan. Of course, during his career, Lloyd was aware of the seemingly intractable fragipan problem. “But with all the other things I was involved with, I didn’t have enough time. So, when I returned in 2013, I involved a soil chemist, soil pedologist and another agronomist and we set about doing lab, greenhouse and field testing on how to break up that cemented layer.” The breakthrough project is described in a lengthy report published last year by the University of Kentucky.

Fragipan soils are present in almost a third of the US, running from east Texas northeast into New York and parts of New England. In Kentucky alone, it hampers agriculture on 2.7 million acres. Fragipan is almost like bedrock in places, beginning anywhere from 18 to 32 inches below the soil surface. The layer becomes cement-like because of an iron-associated aluminosilicate that binds soil together tightly and restricts water penetration and root growth. Crops grown on these soils have limited soil depth, below which crop roots cannot go. Furthermore, in wet weather, fragipan prevents proper drainage. Topsoil gets saturated and squeezes out oxygen, increases the loss of nitrogen, delays planting, and increases the chances of even more soil compaction with any new tractor traffic.

In the 40 years he was researching and teaching the benefits of no-till, Lloyd said he recalled how people were addressing fragipan. “I was involved in early experiments injecting lime or other chemicals into the pan on 30-inch centers, hoping to break it down,” he said. “I was aware of field trials at other universities using deep mechanical rippers to break up the fragipan.  But in a short time, the soil would reconfigure and harden once again. It was quite expensive and none of it proved effective.”

Then in 2014, through the Oregon Ryegrass Commission, Lloyd was introduced to Mike Plumer, another pioneer in conservation agriculture who had been working on contract to the Commission since the early 2000s. It was he who had begun to quantify the value of annual ryegrass as a cover crop. Inadvertently, at Ralph “Junior” Upton’s farm in southern Illinois, they stumbled on the discovery of annual ryegrass’ deep roots. And in the process, they saw how ryegrass roots seemed to be growing into the fragipan on Junior’s compacted acreage.

“Everything happened by accident,” Junior said. “When I started, I only had about 5 inches of topsoil before I would hit the fragipan. I was trying to get through dry weather. I got a grant and started studying no-till and cover crops. Then a representative of Oregon Ryegrass Commission asked me to try annual ryegrass as a cover crop.”

“They’d stumbled onto something really big,” Lloyd said. “Thankfully, Mike and Junior kept good records on their annual ryegrass work. They found that after a few years, the corn production on the acres Junior planted annual ryegrass began to outproduce fields without it. When they started tracking progress on those fields in the early 2000s, he and Mike determined that Junior’s acreage was producing 10 to 20 bushels per acre less than the average in that county. Today, those same acres are producing 40 bushels per acre more than the county average.

New Look: Annual Ryegrass Impact on Fragipan

The short part of this long story is about three things:

  • the impact of compacted soil on crop productivity
  • how to break up compacted soil (fragipan, hardpan) with annual ryegrass
  • how annual ryegrass helps to increase yield of corn and soybeans

Twenty years ago, researchers working with farmers in Illinois found that annual ryegrass roots break up fragipan during winter months, when ryegrass roots permeate compaction and change its composition.

A short demonstration of the results of continuous use of annual ryegrass on compacted soil gradually eliminates compaction and allows cash crops much deeper soil, where added nutrients and moisture are found.

Watch this video and see how annual ryegrass can boost productivity and profits on your farm.

Annual Ryegrass Eliminates the Effect of Fragipan

Fragipan, that compacted soil preventing crop root penetration, covers an estimated 50 million acres of farmland in the eastern US.

Tillage, even deep ripping, didn’t begin to contend with the deeper compaction and layers of fragipan.

Then in the late 1990s, as the idea of no-till agriculture began to gain more attention, an Illinois farmer began to experiment with annual ryegrass to begin to contend with erosion on his hilly acreage.

Junior Upton, Jr. began with a test plot of annual ryegrass. Working with soil agronomist Mike Plumer (U. of Ill. Extension), they believed that annual ryegrass would grow well in low pH soil (like fragipan) and build organic matter because of the vast mat of roots thrown out by annual ryegrass.

He planted the grass seed after harvesting corn and then eliminated the crop a few weeks before planing corn again in the spring.  In a Farm Journal  story a few months ago, by Chris Bennett, he quoted Mike Plumer about that experience with Upton. “In just the first year of use, we saw (annual ryegrass) roots 24″ to 28″,” said Plumer. “The second year was 30″. After four years rooting, (the annual ryegrass root measurement) was at 60″ to 70″,” Plumer added. In normal fragipan, soybean roots often only reach 12″, but after five years of annual ryegrass, Plumer recorded soybean roots at 36”.

The article goes on to say that after killing the annual ryegrass, the roots decay and leave a network of channels for corn or soybeans to occupy. With continuous no-till, the channels created by annual ryegrass allow corn and soybean roots to push deeper each year.

Another discovery: As root depth increases, yields also expand, as Plumer explained . “On Junior’s farm, we’ve got some fields 16 years in the making. His corn yields, before we started, were at a five-year average of 85 bu. per acre, but after six (additional) years (with annual ryegrass cover cropping), he was over 150 bu. per acre. After 10 years, he was over 200 bu. per acre, and it is all documented,” Plumer says.

And the miracle of annual ryegrass continued. As the depth of corn and soybean roots grew, Upton and Plumer measured a remarkable increase in soil nutrients being pulled from deeper soil up to service the crop. “The ryegrass went so deep and picked up phosphorus and potassium. We were doubling and tripling the phosphorus and potassium tests without making applications,” Plumer added.