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Nitrogen and Carbon – Two More Benefits of Annual Ryegrass

In the last blog post, we addressed the myth of annual ryegrass being hard to manage. Follow good control procedures and it is not an issue whatsoever.

Two other assets of annual ryegrass: it creates a savings in expenditures for nitrogen during the season, and it adds considerably to the organic matter in your soil, thus boosts your carbon uptake in the soil as well.

First thing: nitrogen is a key to production. In years past, when cultivation was more popular, nitrogen was increasingly important and expensive. Now, with annual ryegrass as a cover crop, you can actually plan on reducing your nitrogen input. Why? Because annual ryegrass sequesters available nitrogen in the soil during it’s growth. Then, when it’s terminated in the spring, the residue gives up the stored nitrogen, often just in time for the new crop of corn. In many cases, having annual ryegrass decaying in the field means reducing or eliminating the nitrogen boost in June.

Secondly, as the annual ryegrass roots decay (after the cover crop is terminated in early spring), the result is more organic matter, which means more carbon sequestered in the soil, plus more food for a health soil biology.

Finally, when the roots decay, it leaves the earth more pliable, easier for rain to infiltrate, and easier for corn roots to follow. Because annual ryegrass roots grow to depths of five feet and more, it allows corn roots to access that same depth, beyond compaction and into more nutrients like P and K.

It’s amazing that cover cropping, despite it’s proven benefits, is still practiced so infrequently. While it’s great to learn that in some states, 10 percent or more of farmers are using cover crops, it’s discouraging that upwards of 90 percent are still relying on older ways: deep ripping of depleted soils and adding more fertilizer than would be needed if cover crops were utilized.

Understanding the Nitrogen Advantage of Annual Ryegrass

Let’s review the facts about nitrogen, in the context of growing corn in the Midwest, and the connection to ryegrass as a cover crop.

One, corn needs a lot of nitrogen, and if corn is planted year after year in the same field, you will need to add nitrogen to bring the corn to harvest.

You already know that no-till will help stabilize the soil and help it regain its natural health. However, unless you plant a cover crop, you will continue to have to add a lot of nitrogen to feed the corn.

Secondly, it’s known that annual ryegrass “sequesters” nitrogen. As it grows, annual ryegrass absorbs available nitrogen from the soil and then sequesters, or stores, the nutrient in the foliage. When the cover crop is terminated in the spring, all that residual, stored up nitrogen is released. Annual ryegrass, because of its leaf structure, decays quickly in the spring, thus making its nitrogen available to the new corn as it begins to mature in late spring.

Lots of study has been done in the past 10 years about how much nitrogen is absorbed by annual ryegrass, and how much it can contribute back to the corn plants when the grass decays.

At best, the nitrogen that annual ryegrass adds back to the field substantially reduces the need to supplement nitrogen during the year. And, at a minimum, annual ryegrass reduces the costs associated with planting and managing a cover crop.

In an experiment studying annual ryegrass, Farm Journal Field Agronomist Ken Ferrie recorded per-acre costs for annual ryegrass and then calculated the value of the residual nitrogen left over in the spring, when corn was planted. the following graphic box indicates the costs/acre for seed, machinery, herbicide and application costs for terminating the ryegrass.

At the bottom of the graphic box, Ferrie estimates that the amount of nitrogen added back to the soil from annual ryegrass was $75/acre. That is an average and some will experience less, especially if you are just adding cover crops to your management repertoire. However, some farmers have experienced better than $75/acre return of nitrogen from their annual ryegrass cover crop.

So, according to Ferrie, “after subtracting the value of the nitrogen saved, the total cost of the cover crop was $5.75 per acre.” Not bad, especially when you then factor in the added benefits of cover crops: improved soil structure, increased organic matter, increased water infiltration, controlled erosion and recycling additional nutrients, like Phosphorus (P) and Potassium (K). This “recycling” occurs due to annual ryegrass’s deep roots, which helps corn to develop deeper roots to access P and K from deeper soil structure.

Phosphorus is a major component in plant DNA and RNA. Phosphorus is important in root development, crop maturity and seed production. Potassium is required so than more than 80 enzymes in the plant can be activated. K is also important for a plant’s ability to withstand extremes temperatures, drought and pests. Potassium also increases water use efficiency.

Finally, those who plant cover crops consistently experience higher corn yields, which translates into a profit to the pocket as well as to the continued health of farm acreage.

Ryegrass and other Cover Crops – Benefits the Purse and the Earth

You have undoubtedly read, or experienced, the following effects by stopping cultivation, adopting no-till agriculture practices and then planting cover crops, such as annual ryegrass.

Saving on fuel costs by reducing the trips over the field
Reducing or eliminating soil compaction and fragipan layers
Preventing soil erosion
Conserving soil moisture
Protecting water quality
Fixing atmospheric nitrogen while reducing the need for nitrogen fertilizer
Reducing the need for herbicides and pesticides
Improving organic matter, soil porosity and water infiltration
Increasing the population of healthy microorganisms and earthworms
Increasing yields by enhancing soil health

In the last year, another benefit has come to light, based on the collaborative work of two men working on opposite sides of the Atlantic ocean. They claim that cover crops help to mitigate the effects of climate change.

Professor Jason Kaye (Penn. State) and Miguel Quemada (Technical University of Madrid) looked at the following things:

Cover crops lower greenhouse gases by increasing soil carbon sequestration and, thus, the use of less fertilizer
Cover crop vegetation also lowers the proportion of energy from sunlight that is reflected off farm fields.

This last point, according to Professor Kaye, “may mitigate 12 to 46 grams of carbon per square meter per year over a 100-year time horizon.” Click here to read a longer description of the article. Or, click here for the academic study itself.

More Buzz about the Value of Cover Crops

“The good news is, soil will improve every year you grow a cover crop,” said Dan Towery, a crop consultant, and owner of Ag Conservation Solutions, living in West Lafayette, Ind.. “How soon you see measurable yield improvement depends on field history and what limiting factors, such as weather, are present in a year. For example, soils that are low in organic matter will benefit faster from cover crops.”

His comments are part of a longer article in the Farm Journal online. Click here to view the whole article.

Ken Ferrie is also interviewed for the article. Ferrie, Farm Journal’s Field Agronomist said “It might take many years to make big changes in soil health, but in some situations, you might see improvement (earlier than that.). For example, he cited a study in which annual ryegrass as a cover crop improved carbon content, bulk density and water infiltration IN THE FIRST YEAR!.

“As with any new practice, you’ll be eager to determine whether cover crops are having an impact,” Ferrie says. “Your soil physical provides a benchmark so you can follow up later and see if soil health is improving.”

Another farmer and rancher, Gabe Brown, talked about the benefits of cover crops in North Dakota. “You should use covers to address your resource concerns,” advises Brown. For the past two decades, he’s used cover crops to increase diversity, build organic matter, and improve water infiltration and the water-holding capacity of his soils.

“We look at each field separately and determine what the resource concern of each field is,” he says.

But make sure you choose a cover crop with a lot of forethought and advice from others with experience. Otherwise, you may be inviting failure or added problems. “Cover crops take more management, not less,” said Mike Plumer, who died last Christmas after dedicating 50 years to soil health and farmer education. “Farmers have to learn how cover crops react on their own fields.”

Plumer advised producers to start small with cover crops – perhaps a 20 acre plot or so, before “before incorporating on the entire farm.”

Annual Ryegrass Plugging Through another Winter

While the temperatures plunge and the snow whirls, annual ryegrass top growth has been dormant for months. But under the freeze, the annual ryegrass roots continue to flourish, adding depth, girth and mass to a system that builds healthy soil in numerous ways.

The depth of rooting alone is a benefit, because it opens channels in the soil profile. Those channels, next spring and summer, will allow corn roots to seek deeper veins of nutrition and moisture. Even in a dry year, corn that goes deep will continue to thrive. And, with any normal precipitation, those root channels will help the soil absorb the rainfall rather than allowing it to run off.

Annual ryegrass has an appetite for nitrogen, too, so it becomes a storehouse of nitrogen when it grows. Then, in the spring, after it is killed with herbicide (before planting corn or beans), the nitrogen stored in the residue becomes a fertilizer for the hungry corn plants. And the massive root structure of annual ryegrass, when it is killed, that mass degrades and decomposes, increasing the carbon content and organic matter in the soil, giving worms and microbiological organisms a food source.

Because of annual ryegrass’ nature to sequester nitrogen, it’s place in the crop rotation allows you to lighten up considerably on nitrogen inputs.

For more information about annual ryegrass, why it’s beneficial and how to manage it successfully as a cover crop, you can check out this free four-page management guide. Or you can click here to view a series of YouTube videos on the subject.

How Hardy is Annual Ryegrass as a Cover Crop?

In the chart below, you can see color-coded bands that pertain to climatic zones. In the accompanying guide to growing ideal cover crops, the Pioneer and DuPont agronomists determined that annual ryegrass was not recommended for use above Indiana, except in Michigan surrounded by lakes Huron and Michigan.

Plant Hardiness Zone Map

But here’s the catch. If the extreme temperature and wind chills hit annual ryegrass uncovered, it can certainly kill it off, or knock it back significantly. What is key to know, however, is that if the plant has snow cover to protect it from the icy blast, it can survive winter perfectly well.

In southern Canada, Ontario and Quebec specifically, lots of farmers use annual ryegrass each year. Their usual snowfall almost guarantees a healthy winter for annual ryegrass. Farmers in Minnesota and North Dakota also find annual ryegrass a viable cover crop even with their harsh winters, again, because of adequate snowfall.

In the report’s other graphic, showing the attributes of different cover crops, it shows annual ryegrass as ideal for a variety of reasons, namely for scavenging nitrogen, busting up compaction, preventing erosion and building organic matter. Click here for more information on growing and managing annual ryegrass as a cover crop.

Annual Ryegrass Video Series – for beginners and intermediate cover crop users

The experts said it back in 1998, that no-till and cover crops were a winning combination for corn and soybean growers. Ten years later, a series of videos were done to introduce the idea and bring basic understanding of the what and how of cover crops. Back in 2005, the idea that a cover crop could sink winter roots down to 50 inches or more was revolutionary in the ag industry. Today, the practice is becoming widespread in the Midwest. The videos stand up to the test of time, and continue to be a solid source of information.

In the first video segment, you can get a glimpse of the main characteristics of annual ryegrass, and a couple of its major benefits.

Root depth: “Better than a deep ripper, in terms of its ability to break up compaction,” said Dan Towery, of Ag Conservation Solutions, an Indiana consultant on soil health.”Far deeper than other cover crops,” said Mike Plumer a former university agronomist and pioneer in cover crop development in the Midwest.

Nitrogen scavenger: those who use livestock manure in the field benefit by having the nutrient stay in the field.
“Annual ryegrass is a great nitrogen scavenger,” said another cover crop pioneer in Indiana, Dan DeSutter, …keeping it in the field instead of sending it down the tile lines in the spring with runoff.”

If the videos are of some interest, perhaps you would also like more information about the science and the management of annual ryegrass. If so, click here for a free brochure. Or, click here for a library of information on the annual ryegrass website.

Annual Ryegrass Has Important Benefits

Farm Progress published a management guide for growing cover crops…it’s available FREE online. Click here. (You will be asked to fill out the information they want – name, email address – before emailing it to you free.)

Cover Crops: Best Management Practices

Here’s part of what the report says about annual ryegrass:

Today, farmers often hear about annual ryegrass and cereal rye grain as popular cover crop choices. It’s important to know the differences of each of these cover crops. Annual ryegrass is a versatile cover crop choice that will protect the soil, reduce soybean cyst nematode populations and hold nitrogen through the winter. Annual ryegrass – which is often referred to as “ryegrass” – has about 33% more roots than cereal rye and provides higher quality feed than cereal rye grain. Annual ryegrass is lighter than cereal rye grain and farmers and custom applicators using high clearance, drills, spreaders for dry fertilizer and airplanes can seed more acres before having to refill than if they choose cereal rye. Annual ryegrass needs to be seeded in August into early and mid-September, depending on location and the weather, while cereal rye grain can be seeded later in the fall, often into October. That, of course, also depends on the weather and location.

If you regularly plant cover crops, it’s probably a safe bet you’ve planted by now. If you’re considering planting a cover crop for the first time, looking at Farm Progress’ Management Guide is a good start. You can also find tons of detailed information about growing and managing annual ryegrass by clicking on this link, which will take you to the annual ryegrass website.

Or, click here to look at videos that discuss various aspects of managing annual ryegrass.

New Midwest Incentives for Cover Crops

Among other things, Dan Towery manages the Indiana part of the Soil Health Partnership, a network of innovative farmers in eight Midwest states. Dan has been a consultant for the Oregon Grass Seed Growers Commission that promotes use of annual ryegrass as a cover crop for more than a decade. He has been a steady voice for conservation agriculture since he graduated from Western Illinois University.

Dan was a staff agronomist for the Conservation Technology Information Center and was state agronomist in Indiana before joining the staff of the Natural Resources Conservation Service (NRCS). In recent years, Dan’s been tireless making connections – both one on one with Midwest growers – as well as nationally and in other countries, with leaders of industry, policy and conservation. That work created a natural space for him on the board of the International Soil & Water Conservation Society board for 6 years. He was selected as its president in 2012 and 2013.

This past growing season, the Soil Health Partnership conducted more than 40 field days in eight states, attended by more than 1500 farmers, eager to learn from each other the details of managing cover crops. The field days covered subjects like cover crops and other soil improvement methods, as well as equipment, nutrient management and other topics. The initiative, sponsored by the National Corn Growers Association has also gained tremendous support of a dazzling variety of groups including Monsanto, NRCS, the United Soybean Board, the Walton Family Foundation, the Midwest Row Crop Collaborative, the Environmental Defense Fund and the Nature Conservancy.

In September, largely because of its effective promotion of conservation tillage in the Midwest, the Soil Health Partnership learned that it won a $1 million Conservation Innovation Grant from the U.S. Department of Agriculture. The grant funding will help to quantify the gains being made by farmers using cover crops and other conservation strategies, according to a news release from the organization.

Farmers enrolled in the SHP program will be invited to participate in the carbon reduction incentive system, in which growers are paid by corporations to sequester carbon in their soil, according to the article.

“This is a great opportunity for farmers to continue being a part of the solution to carbon sequestration, and gain financial incentives for carbon-smart ag practices like growing cover crops and using minimum tillage,” said Nick Goeser, NCGA director of soil health and sustainability and director of the SHP. “We hope to provide businesses with a quantifiable method to reduce their carbon footprint by increasing these on-the-ground conservation practices.”

Cover Crops in the Midwest Saves Lives in the Gulf

Agricultural runoff has dramatically altered life in the shallow waters of the Gulf of Mexico. Hypoxia, in essence the cutting off of oxygen, has choked off aquatic life in the Gulf. Continued practices will essentially kill off life, and the massive fishing industry will die with it. In the photo below, you can see the massive amount of farmland drained by the Mississippi River system into the Gulf.

Image result for hypoxia in the gulf photos

Cover crops can significantly reduce the amount of runoff, particularly nitrate, into the streams and rivers that supply the Gulf from the Mississippi River. In fact, in a study conducted by Eileen Kladivko (Purdue Univ.), Tom Kaspar (USDA-Iowa) and others, they estimate that the adoption of cover crops more uniformly by farmers, in just five Midwest states, can reduce the amount of nitrates by an estimated 20%. These five states (Ohio, Indiana, Illinois, Iowa and Michigan) are responsible for almost HALF of the nitrate loading in the Gulf.

Here’s a link to the study (click here)

The study looked only at cereal rye as a possible cover crop. Use of annual ryegrass has benifits over cereal rye.

It has deeper roots, which means deeper nutrients and moisture for corn and soybeans. Deeper roots also means less compaction
Annual ryegrass is a scavenger of nitrogen. In addition to saving on inputs of fertilizer, annual ryegrass stores nitrogen and then yields it to the corn in the spring, when the grass is killed.

Check out the other differences between annual ryegrass and cereal rye in this publication. Among other things, cereal rye can tie up nitrogen too long, thus requiring added inputs for corn growth. And, cereal rye can grow too much on the surface (6 -7 feet) and thus make it difficult to plant into in the spring. Annual ryegrass, on the other hand, releases nitrogen in time for the corn to use efficiently. And it’s root mass creates more biomass in the soil, thus creating more food for worms and microbes, more organic matter and healthier soil.

Ryegrass Cover Crop

A Cover Crop that Builds Soil and Boosts Production