Tag Archives: improve organic matter in soil

Annual Ryegrass – At the Root of it All

The Dust Bowl crippled the Great Plains states in the 1930s and 40s because of poor soil management in the decades before that.

The mistakes made were partly because of economics – farmers were rewarded for expanding their acreage in order to satisfy the demand for corn and wheat to supply troops in World War I. But the mistakes were also due to the fact that most farmers did not understand the effect of plowing under the native prairie grasses to make room for cash crops. And, after World War II, the popular thing was to make use of the bountiful supply of anhydrous ammonia (high in nitrogen) for supplying the nutrients lost to oxidation and erosion.

Annual ryegrass is akin to those native prairie grasses in at least one respect: they all have very deep roots. And, as you know, it is the roots that protect the soil surface from erosion. Modern agricultural methods include cover cropping, which prevents nutrients from eroding off the property. No more waste of topsoil; less need for adding nutrient inputs to bolster anemic soil.

Corn roots in ARG 6-06 Starkey

The other key factor with annual ryegrass’ deep roots is that they seek moisture and nutrients in deeper soil. Roots grow to depths of 6 feet in some places. The benefit is that roots from ryegrass create channels for the corn and soybeans to follow. Once the cover crop is killed in the spring, the roots die and add to the organic matter in the soil, in addition to creating pathways for new rooting crops and infiltration of snow melt and rain.

The annual ryegrass website has tons of good information about growing this cover crop. There are videos, too, and you need only click here. Finally, No-Till Farmer magazine has an article that talks more about the benefits of annual ryegrass.


Old Ways Fade as Cover Crops Gain Favor

Iowa isn’t known as an early adopter with cover crops. But according to an article in Farm Journal recently, more than half of the acres in production in that state are leased. So, while farmers themselves may choose to do what’s best for the soil, owners may be reluctant to invest.

Nonetheless, the article went on to say that about 25 percent of Iowa farmers claimed to be using cover crops, though most said the acres committed to the conservation tillage measure were small…usually less than 100 acres.


That’s great news, because it suggests that owners are beginning to see that investment in conservation tillage brings dividends. According to the article:

Researchers say that landowners could benefit economically from farmer adoption of conservation agriculture, which can reduce in varying degrees the use of fertilizer, pesticides, fuel, equipment and labor. Crop insurance provides another potential opportunity in light of evidence that conservation agriculture can increase crop resilience to weather threats such as droughts or floods.

In the article, reference was made to a 2010 study by the University of Illinois (another latecomer to the value of cover crops) that concluded that the jury is still out on whether cover crops increase yields for corn and soybean crops (we believe it is conclusive that they do). But the study did say that cover crops significantly increase the amount of organic matter in the soil, which indicates soil health.

…it does increase the amount of sequestered soil organic carbon. Soil organic carbon stock gains were 30% higher for no-till, 10% higher for chisel plowed and 18% higher for moldboard-plowed plots.

“This suggests that soil organic carbon stock losses from tillage, water erosion and some disturbance or mixing during no-till planting, aeration, nitrogen injection in corn years and mineralization were less than the soil organic carbon gain from the cover-crop treatment,” says U of I soil scientist Ken Olson.

Cover Crops Benefit Soil Microbiology, including Fungus

Soil is alive…literally…and it hosts hundreds of thousands of different living organisms: insects,worms, microorganisms, bacteria, etc. Tilling in the old fashioned way strips life from the soil. Cover crops restore soil health and these different life forms are part of that important balance. Farmers realize that when the soil is happy, crops grown in the soil tend to thrive. Your soil, kind of like a dependent child, needs constant nurturing and healthy practices to grow strong and productive.

Part of that rich mix of life in the soil include Mycorrhizal Fungus. The fungi send out rootlike extensions (hyphae) which take up water and soil nutrients.  Plants produce sugars (polysaccharides) in their leaves and send them to the roots. Together, this symbiotic relationship produces a protein (glomalin) which captures and groups particles of organic matter, plant cells, bacteria and other fungi together. The soil takes on a crumbly texture, which creates the lightness and porosity that allows better drainage. Glomalin is a key part of important substances in promoting and stabilizing soil aggregates. It also aids in plant uptake of water and nutrients.

Glomalin - plant roots and mycorrhizal fungus



Illinois Makes Strides in Conservation Tillage and Cover Crops

The American Farmland Trust says this about the Midwest’s heritage in agriculture:

With flat prairies, plentiful water, and rich, deep soils, the Midwest is one of the most intensely farmed regions in the world. We depend on it for many of our grocery staples – from corn and soybeans to wheat and meat.

But the Midwest’s abundance of fertile farmland has sometimes led us to take it for granted. We’re rapidly paving over some of the most productive soils and farmland in the world.

At the same time, tons of prime topsoil washes away – and we can’t afford to lose it. In the Midwest, we need to save the land – not just by the acre but also by the inch.

Illinois, 2nd in the nation in production of corn and soybeans, has been somewhat late to the table on soil conservation methods. Cover crop pioneer Mike Plumer worked for decades for Illinois’ major ag university as an Extension educator and agronomist. Despite his untiring advocacy for no-till and cover crops, his university seemed indifferent and even adversarial to his claim that conservation practices were the future of agriculture. Adverse to change, some believe that quality soil will continue without fail, and what dips in productivity one experiences, you can augment with chemistry.

Another Midwest pioneer in cover crop practices, Dan Towery, hails from Indiana, but his work has taken him far afield, and also in close-by partnership with Plumer. His current involvement in a NRCS and SERE project in Illinois, however, spells good news for the day when Illinois will hit its stride with its neighbors, advocating soil conservation, better soil management and improved water quality..

A sign of things on the move in Illinois is the information available from the NRCS office. CLICK here for a look.

And, through NRCS and EQIP, funding is available this year for Illinois growers interested in doing more to save the quality of their soil through conservation measures, like cover crops. CLICK here for an application, courtesy of the Illinois Council on Best Management Practices.


Field Day for Cover Crops in Illinois

MO-Matt-Volkman-NRCS-ARG-field-shot.jpgA cover crop field day has been scheduled at two locations in Illinois’ Coe Township, convened by the Rock Island Soil & Water Conservation District.(See below for specifics)

According to an article in the Dispatch-Argus paper in Moline, IL, cover crops continue to prove their value, both in building soil health and improving profits for growers. Here’s a segment of the article (if you want to read the whole thing, click here)

Cover crops lengthen the growing season of live plant material with many winter annual species like winter wheat, cereal rye and annual ryegrass maintaining live root systems under the soil surface during the winter months providing food for soil microbes to stay active.  Currently, idle crop fields become biological deserts in which soil microbes reduce in population with limited food resources.  Some covers like cereal rye and annual ryegrass also provide biological weed control in crop fields during the early portion of the growing season.  This helps reduce the amount of pesticides that need to be used.”

“Those benefits include reduced soil erosion, enhancement of soil biology through increased microbial activity and the development of higher organic levels, improved water quality from reduced run-off along with the capture of un-used phosphorus and nitrogen making those nutrients available for the next cropping season.”

Location of the field days:

Wed. Nov 5th – DePauw farm, located at 122nd Ave N, in Port Byron, IL.

Thurs. Nov. 6th. – the Anderson Farm located ½ mile east of Sherrard High School or west of the junction of 176th Ave W and 63rd St. W.

For more information and reservations call the Rock Island SWCD office at (309) 764-1486 ext. 3.

Annual Ryegrass Roots – What’s Going on There?

Pioneering cover crop use in the 1990s, University of Illinois Extension educator Mike Plumer discovered something that surprised everybody. Annual ryegrass has a root structure that grows to depths of more than five feet over winter, while the top growth is pretty much dormant.

One of annual ryegrass’ most compelling features is that deep rooting system, because it breaks up compaction of all kinds, and in doing so, it also helps bring nutrients deeper in the soil profile up to the surface. This not only helps crops thrive, it also reduces the amount of nutrient inputs needed.

So, it’s unclear why Cornell and Michigan State universities still have printed information about annual ryegrass stating that annual ryegrass has “a shallow” rooting system.

In fact, the plant DOES have a shallow root mass, which makes  it valuable for preventing erosion. But what they don’t say is that annual ryegrass roots also grow to depths of five feet. And this is equally important, for reasons stated above.

In sum, the combined root mass of annual ryegrass also provide another benefit: helping to build organic matter in depleted soils. Once the plant is terminated, in springtime just before planting corn or soybeans, all that root matter decays and becomes the basis for a healthy population of microorganisms and a more friable soil.


soil pit2


(In the photo above, growers are inspecting deep channels created by annual ryegrass roots, which allow corn roots more penetration into the soil following those same channels. Thus, corn plants can better tolerate dry weather because they can reach deeper into soil for needed moisture.)

Plumer said that because of long-term tillage practices, plus tiling fields for drainage and not planting cover crops, Midwest soils have lost half or more of their organic matter. The good news is that for every additional percentage point of organic matter you can add back into the soil, you’re adding back about 1000 pounds of nitrogen per acre!

Annual ryegrass and other cover crops help to raise the organic level back up, though it takes years of consistent cover crop use to make up for the decades of less productive management methods including heavy tillage.

Cover Crops and Grazing in Your Future?

A Pennsylvania Extension educator has shown that intensive grazing on cropland low in organic matter can rebuild the soil quickly – in a matter of a few years in some cases. The cover crop and grazing practice also led to a “drastic increase in cation exchange capacity and water holding capacity of the soil,” according to the author, Sjoerd Duiker. (Read the article by clicking here).

Cation exchange capacity (CEC) refers to the soil’s capability to store and then provide certain nutrients, like calcium and magnesium, to crops grown on the soil. While soil types tend to dictate a CEC range, building soil organic matter greatly increases the capacity for cation exchange. That, in turn, determines the productivity of the soil and how much fertilizer you need to add.

Duiker said he sees potential for increased profitably by bringing grazing animals back on the croplands in the US. Crop and livestock experts he talked to advised combining nighttime-grazing and daytime stall feeding to allow for continued high milk production (75 lbs/day).

In terms of cover crop varieties used, Duiker mentioned annual ryegrass mixed with triticale for fall and spring forage and other crops like tillering corn, sudangrass, sorghum-sudangrass hybrids and forage soybeans, cowpeas, brassicas and sunnhemp for the rest of the year. He said that perennials are “tremendous soil builders and the annuals add benefits such as meeting forage needs during the summer slump when the weather is hot and dry as well as in late fall, and are a break crop between an old and new perennial pasture stands.”

Return on Investment from Cover Crops – 266 % – say Indiana Farmers

No-Till Farmer magazine just published a great article that quantifies the benefits of cover cropping. In this case “quantifying” means translating more than a decade of field data into dollars saved.

The article (click here) looks at data collected by two Indiana family farmers as well as the NRCS. The pair presented the data at this year’s Iowa Cover Crops Conference. Look at the following charts. The first contains the costs for cover crops – seed and planting: about $26/ac.

The second chart looks at the benefits: fertilizer saved, corn yield increase, soybean yield increase (less disease), drought tolerance (a 10 year average), increase in organic matter and erosion reduction. Ken Rulon, one of the farmers, said that the “return on investment” has been 266 percent, with a net benefit/acre planted at $69.17. Even if he had gotten only half the benefits, it would still be profitable, he said.

Annual Ryegrass Roots…”Go Dig!”

“My cover crop wasn’t green this spring!” Don Wirth’s answer to what sounded to him like a complaint was, “Go dig!”

His point: when annual ryegrass is established in the fall, it quickly sends roots down below a foot, even in fields that haven’t had a cover crop before. (In successive years, annual ryegrass roots can send roots to deeper than 40 inches, even when there’s only a couple of inches of top growth!) It is those roots that help prevent erosion. But that’s only the beginning. Deep rooting breaks up compaction, improves permeability. That’s still only the beginning. The biggest benefit is that cover crops improve soil biology, including a healthy population of earthworms and microorganisms. When that happens, crops thrive, production increases and costs for inputs go down.

A few years ago, he visited a Midwest farm in the spring, where no cover crop was evident on the surface. And yet, walking across the field, Don was able to point out where the annual ryegrass had grown the year before. It was as if a line had been drawn on the land. Cover crops had already begun to change the biology of the soil beneath. “I’m guessing that the field had very low organic matter content, so the addition of even a year’s worth of cover crop will make a significant difference in how the soil looks and feels,” he said.

Wirth, an Oregon grass seed farmer said there is a lot of reliable information now about the value of cover crops. But he heartily suggests that farmers be more informed about the health of their soil. He recommends reading Gary Zimmer’s book Biological Farmer, written in 2000. Here’s a short excerpt from the book’s description:

Biological farming does not mean less production; it means eliminating obstacles to healthy, efficient production. It is a safe and sustainable system designed to keep production up.
varner arg michigan 4-08 (2)

Wirth also suggests becoming more in touch with improving your soil’s health. He said starting with an inexpensive Solvita test (about $150) will give you some basics.

The test uses a couple of soil probes loaded with a certain kind of gel that reacts to soil chemistry. Among other things, the Solvita measures carbon dioxide emissions…mostly due to microbial respiration. The level of microbial activity indicates the amount of active organic matter that is being broken down and the amount of nutrients being released.

Measuring year after year will give you a chart of the growth in soil biology and organic matter. Overlay that on a record of crop yields and you’d have pretty convincing evidence about the connection between cover crops,
soil health and profits.





Annual Ryegrass Helps Soil Microbiology Helps Soil Health

“Many times during a drought, plants are not as much water stressed as they are nutrient stressed,” said USDA soil microbiologist Kris Nichols.

Cover crops feed a whole web of soil organisms…much more than mere crop residue. Those organisms seek carbon and they get it from live plants like corn.

Nichols said that the microbes, in exchange for carbon, give up nutrients and water which they get from the soil.

Mycorrhizal fungi are an example Nichols uses to explain the value added that microbiology brings to crops. The little critters are threadlike, much smaller in width than plant roots, and have more access to more soil than plants.

Cover crops like annual ryegrass are conducive to production of healthy mycorrhizae population and create a symbiotic relationship helping the fungi, the soil and the plants. “Plants growing in soils rich with mycorrhizae take advantage of the fungi to help them obtain nutrients from the soil,” she added.

“They accomplish this using much less water, as well,” Nelson continued. The soil structure, rich with microorganisms, is more conducive to water retention, as she explains, “Organisms help form soil aggregates, which allows for better water absorption because there is more pore space in the soil for water as well as an exchange of gas.”