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EDITORIALS

Producers weigh in on benefits of fall cover crop grazing

Iowa Beef Center
Many research and demonstration projects have focused on using cover crops for spring grazing or spring harvest, but few have focused on the use of cover crops for fall feed.

Establishing cover crops following grain production is a proven tool to protect soil, reduce erosion, improve water quality, and enhance soil quality. Many research and demonstration projects have focused on using cover crops for spring grazing or spring harvest, but few have focused on the use of cover crops for fall feed.

As part of a demonstration project funded by a North Central Risk Management Extension Education grant, Iowa State University Extension specialists conducted interviews with producers across Iowa who had used fall grazing for at least two years. The cooperating producers were asked about a variety of topics, including their individual farming operations, cover crop species selection, seeding methods and rates, and animal health concerns.

ISU Extension beef specialist Denise Schwab was part of the team conducting the interviews. She said the results from those real-world experiences form the basis of a new publication, “Farmer Experiences with Fall Grazing Cover Crops” now available as a free download from the Iowa State extension store.

“Variable late summer, fall and winter weather is a factor in the challenge of both research and on-farm success with fall grazing,” she said.  “However, extending the fall grazing season with cover crops can significantly reduce stored feed costs even if it is only for a few weeks.”

Highlights from the report include:

Managing multiple enterprises

There are many advantages of cover crops including reduced soil erosion, improved soil tilth, water infiltration rates, retention, and cycling, reduced weed pressure, disease break in short rotations, and nitrogen capture and recycling. Farmers often point out that cover crops are difficult to justify economically because there appears to be no immediate economic benefit to the grain producer for seeding cover crops. However, cover crops do have immediate economic value when incorporated with a ruminant livestock system.

Costs and benefits

Several cooperators commented on the economic benefit to the cow herd by reduced feed cost, although no direct economic benefit to the agronomic budget. Research has shown that cropping practices become more financially attractive when livestock production can be gained from the system, including the development of Iowa State University partial budgets for corn and beans following cover crops based on input from producers’ actual experiences.

Species selection

Appropriate species selection is important to insure fall growth for grazing. Cover crop species selection should involve considering the animal’s nutritional needs, timing of seeding, when grazing will occur (fall or spring), and limitations by pesticide label restrictions.

Spring cereal grains and winter cereal grains were the most popular cover crop species used by cooperators, which is consistent with a survey by Iowa Learning Farms looking at what cover crop species farmers are planting.

Pesticide labels

Project cooperators acknowledged the importance of reading pesticide labels prior to planting any cover crops, especially herbicide labels when grazing or harvesting cover crops for feed. One of the primary reasons for label restrictions on cover crops is that herbicide residues may prevent establishment of cover crops. A second major concern with herbicides prior to cover crops is the lack of research to establish safe residue tolerance for grazing the cover crops.

Seeding methods

Interseeding, aerial seeding, drilling, and broadcasting are common cover crop seeding methods. Seventy percent of the cooperators drilled their cover crops after harvest, almost half aerially seeded, and one quarter broadcasted their cover crop seed. Note that almost half cooperators reported using more than one seeding method depending on the weather, previous crop, and if they intended to graze it or not.

Extending the fall grazing season with cover crops can significantly reduce stored feed costs even if it is only for a few weeks.

Seeding rates

Seeding rates used by cooperators varied depending upon seeding methods and species planted. In general, cooperators said they used higher seeding rates if they broadcasted or aerial seeded the cover crop, and they used lower seeding rates if they drilled the cover crop.Cooperators’ cost of cover crop establishment (seed plus seeding method) ranged from $20-45 per acre.

Grazing management

Four cooperators rotationally grazed the cover crops and stover in an effort to control the diet and improve utilization of the lower quality corn stover, while 14 cooperators continuously grazed the covers. However, several indicated they move from field to field, so are essentially rotationally grazing by field. All included crop residue along with the cover crop, so it is difficult to determine what part of the ration is due to the cover crop versus the crop residue.

Animal health concerns

While there have been reported cases of animal health concerns when grazing cover crops, none of these cooperators reported any animal health concerns while grazing. Additionally, no cooperators reported concerns or issues with nitrate or sulfur toxicity; however, that is a possible concern when grazing cover crops.

Summary

Establishing cover crops in Iowa to ensure adequate growth for grazing in the fall is feasible but not a sure bet every year. Despite the challenges related to early seeding and warm growing weather, fall grazing of cover crops can be an economical source of feed for beef cattle. Even in years when there is not enough forage for grazing in the fall, there may still be the opportunity to graze or mechanically harvest feed in the spring depending on the cover crop species utilized.

Six cooperators in the project encouraged first-time cover crop grazers to start small but “just do it.” While fall grazing may not be a success every year, in the long run Iowa cooperators feel it has been beneficial to their farming and livestock enterprises. Cooperators also encouraged new users to not give up if the first year doesn’t work well.

This publication is a compilation of the producer comments and research that supports their practices. The 20 cooperators who were part of this project ranged from having two to 30 years of experience seeding cover crops with an average of 10 years of experience per producer. The cooperators averaged almost 400 acres of cover crops seeded annually.