Cover crops add grazing option

Cover crops can keep the soil covered between growing cash crops in a field. Cover crops increase soil organic matter, improve water quality and reduce erosion during some of the most vulnerable times of the year. But cover crops can also be grown to extend the grazing season and reduce the need for stored forages, or free up pastures to increase rest periods or make more hay. There are many different strategies of how farmers are doing this.

Wade Dooley, farming near Albion in central Iowa, grazed winter wheat and winter rye last fall and spring. He seeded 20 acres of winter rye following corn silage, seeding the rye in mid-September. And 30 acres of winter wheat were broadcast-seeded with a highboy into standing soybeans at the leaf yellowing stage — also in mid-September.

Key Points

• Cover crops can extend grazing season and reduce the need for stored forages.

• Practice benefits water and soil quality, pays for itself, and can even make money.

• Cover crops such as rye can also be harvested and stored as forage.


In November, 65 head of cow-calf pairs (1,200- to 1,500-pound cows) and four bulls were put into the rye, plus 70 additional acres of cornstalks. The calves were weaned, and the bulls were removed after Thanksgiving. The rye and cornstalks were grazed for one month with corn silage, but no additional feed was provided. The cows were then moved into the winter wheat, and half a day later it snowed. The cows were fed hay and corn silage in this field the remainder of winter.

Graze wheat, rye in spring

As soon as the snow melted, the wheat (which had been insulated under the snow), started growing and the cows started grazing it. They grazed the wheat until the rye was 6 inches tall. They then moved to the rye and adjoining 70 acres of cornstalks with no cover crop, until the rye had been eaten down.

Dooley then moved the cows back to the winter wheat field to allow the rye to grow back again. He rotated the cows back and forth between the rye and the wheat three times a month for two months, after which the rye regrowth no longer seemed to be palatable to the cows. The winter rye field was planted to soybeans and the winter wheat field was planted to corn.

Here’s the exciting part: For the first time, Dooley had extra hay this spring. That’s because he fed no hay in the fall and reduced hay feeding in spring when the cows were grazing cover crops.

During the spring grazing, he fed the cows the same as he normally would: corn silage and hay as needed. But he moved to every-other-day corn silage feeding earlier than he normally would have, as the cows did not seem as hungry. They also ate considerably less hay than usual. The only difference was he added the cover crop as a feed source.

Practice pays off in several ways

Dooley says this conservation practice benefits water quality and soil health, pays for itself and can even make money. It saves on feed costs, keeps cows cleaner during mud season (with no bedding cost) and spreads out the manure nutrients with no labor or fuel needed.

Another advantage, Dooley notes, is fields with cover crops held up under the weight of a manure spreader, while the spreader sank in wet fields with no cover crops, forming huge ruts.

This could be a function of two things: The plants were actively taking up water, leaving the soil drier, and the living plants and roots provided better soil structure to support weight. This could help dry out the soil for planting in wet springs, but it could also become a problem in areas and years when water is scarce.

What about fall grazing?

Another farmer who grazes winter rye is George Schaefer, who farms with his brother Steve at Kalona in southeast Iowa. In the past they have drilled rye following corn harvest, but last fall they had the rye aerial-seeded into standing corn as part of a Practical Farmers of Iowa and Iowa Learning Farm research project, comparing side-by-side treatments of a winter rye cover crop and no cover crop.

If the rye gets significant fall growth, they will graze it in the fall along with cornstalks. In the spring they graze the rye when it gets about a foot tall (assuming the field is in a location that can be grazed). This spring they grazed rye for about a month.

The Schaefers warn that if you are replacing spring pasture with rye grazing, some of the pastures should be hayed for the grass to not get overly mature by the time you get to grazing it in your rotation. This was especially a problem this spring with all the moisture their farm received (18 inches in June), as the mature grass, which did not get mowed, got trampled on the ground, retarding regrowth. This is also an advantage, though, to either make more hay in the spring or give pastures more rest.

Prepare fields for planting

The brothers also say any cover crop fields that get grazed must be tilled before planting corn or soybeans, as the field will have hoof marks that make it difficult to get a good no-till stand. On the Schaefers’ organic fields, this is especially true, as grazing the cover crops would delay the time until boot stage, when they would be able to shred the cover crop before organic no-till beans.

Cover crops such as rye can also be harvested and stored as forage if fencing is lacking or the location makes the field unsuitable for grazing. The brothers did this on some fields this year. Ideally, the rye should be harvested in the flag leaf to flowering stage, but waiting for this stage in the spring could delay planting of the main cash crop, such as corn or beans. Perhaps planting a shorter-season corn following harvest of the rye forage would work, says George.

Dietzel is a grazing management specialist for Practical Farmers of Iowa.

Interim DNR director selected

Iowa Gov. Chet Culver has appointed Pat Boddy interim director of the Iowa Department of Natural Resources. She served as deputy director the past two years and succeeds Richard Leopold, who recently resigned to take a job with the U.S. Fish and Wildlife Service in Minneapolis.

Boddy is a licensed engineer and a former director of the Polk County Conservation Board. She has an undergraduate degree in journalism, an undergraduate degree in ag engineering and a master’s degree in water resources from Iowa State University.

Leopold will become Midwest assistant regional director for science applications for the U.S. Fish and Wildlife Service. He had been head of the Iowa DNR since January 2007. Leopold previously headed the nonprofit Iowa Environmental Council. Appointed in 2007 by Gov. Chet Culver to head DNR, Leopold pushed for tighter controls on agricultural pollution. He was widely supported by environmental groups, but was less popular with farm interests, such as the Iowa Farm Bureau.

Iowa Citizens for Community Improvement considered Leopold too soft on farm interests. “He did not stand up to Farm Bureau and other corporate ag groups,” says Hugh Espey, ICCI director. “More often than not, he sided with industry over the interests of everyday people and the environment.”


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EXTEND GRAZING: A conservation practice that pays, fall-seeded cover crops can be grazed in spring to reduce the need for feeding hay and it frees up pastures to increase rest periods or make more hay, says Wade Dooley.

This article published in the September, 2010 edition of WALLACES FARMER.

All rights reserved. Copyright Farm Progress Cos. 2010.