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Grazing Cover Crops

COVER CROP TRAINING MODULE

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Developed by

Joe LaRose, University of Missouri

Reviewed by

Dr. Harley Naumann and Dr. Ashley Conway (both U of MO), Alan Weber (producer who grazes cover crops) and Dr. Rob Myers (U of MO)

Funded by

Walton Family Foundation

These training modules are being made available by free use of other educators through University of Missouri and the Midwest Cover Crops Council, which participated in the WFF project supporting development of these modules and provided many of the technical reviewers.

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Why Consider Grazing Cover Crops?

Row crop farmers

Recoup cost of cover crops
Enhance soil health and fertility
Justify diversifying rotations

Livestock owners

Save cost on feed when it is most expensive (winter, late summer slump)
Increase herd size
High quality forage
Rest perennial pastures
Calving area

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Grazing vs. Harvesting Cover Crops

Harvesting cover crops for stored forage such as hay or baleage can be profitable

However

Removes nutrients

Less soil protection

Reduces food for soil microbes

No fertilization from grazing livestock

University of Vermont

UGA Extension

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Getting started grazing cover crops

Basics: fencing, water, compaction, management

Maximize grazing potential: choosing cover crops and increasing their growing time

Redesigning cropping system: use cover crops to fill gaps in forage production and to diversify crop rotation

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Basics: common concerns

Fencing

Fear: Expense

Fact: Electric fencing can be very affordable. Many farmers grazing cover crops do not need permanent exterior fencing

Fear: Electric fencing is a hassle

Fact: Can quickly be put up and taken down with step in posts

University of Maryland Extension

Fencing is often the number one reason that farmers do not want to graze cover crops. Traditional barbwire fences are expensive (4 strand is ~$5000 per mile), require a lot of maintenance, and are hard to remove. Electric fencing is better on all three fronts, (~$1600 per mile). Perimeter fencing can be high tensile, which is still cheaper and easier than barbwire, or it can be single or double strand electric polywire. Farmers with livestock, especially sheep and cattle, trained to electric fencing can use one-wire interior fencing may be able to use one-wire perimeter fencing as well.

Electric fencing also allows for strip grazing stockpiled forage in the winter, which means farmers don’t have to haul hay to livestock as often, if at all.

Prices from https://prod.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs144p2_010636.pdf

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Basics: common concerns

Fencing
Water

Fear: Requires numerous expensive watering systems

Fact: Portable water tanks are affordable and simple to use.

Fear: Winter water problems

Fact: Continuous flow systems are a well-established solution to winter water. Also, cattle can walk up to a mile back to water in cool temperatures

University of Kentucky

NRCS

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Basics: common concerns

Fencing
Water
Compaction

Grazing cover crops can decrease compaction overall by increasing soil aggregation.
Shallow compaction from hoof traffic has little to no impact on corn and soybean yields
Rotate livestock
Use sacrifice lots during wet periods

Grazing cover crops appears to decrease overall compaction through better soil aggregation that arises from manure and plant root response to grazing. That said, cover crops are not an excuse to implement a poor grazing system. Overstocking, continuous grazing, lack of sacrifice lots, and inefficient watering systems will lead to compaction in cover cropped fields just as they do in pastures.

To prevent compaction:

Practice rotational grazing. Allowing time for the plants and soil to rest and recover from grazing is important.
Keep of fields during wet periods. If its is very muddy, livestock can make a mess and cause compaction. Livestock should be moved to a designated sacrifice lot: an area that a farmer is ok with being torn up during wet periods.

Figure from:

https://www.iowalearningfarms.org/files/page/files/Cover%20Crops%20and%20Soil%20Compaction.pdf

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Basics: management

Practice rotational grazing if possible

To graze regrowth in spring, keep above 3 inches in winter so plants have the energy to grow quickly in the spring

Kable Thurlow, MSU

The specific management techniques for grazing cover crops will be different for every farmer depending on the cover crop, geography, time, and type of livestock. There are some basic tips that apply in most scenarios

Rotate livestock both to maximize forage utilization and protect the soil. Rotational grazing encompasses infrequent paddock changes every few months to intensive management, in which livestock are moved frequently, even multiple times a day. Moving livestock frequently through cover crops can seem intimidating and like a lot of work, but temporary electric fencing is can actually take less time than hauling hay.
Do not overgraze if you want to get multiple grazing events out of the cover crop. For winter cover crops, farmers should leave at least 3 inches of forage to allow the plants to overwinter and bounce back well in the spring

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Maximize grazing potential

Managing cover crops for grazing

Seeding rate

Increased 1.5-2X for small grains, legumes a small amount
No change for brassicas

Fertility

Typically not worth investment

Ryan et al. 2011

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Maximize grazing potential

Managing cover crops for grazing

Seeding rate
Fertility
Extend season

Fly on cover crop
Interseed (V6-V7 most common timing)
Earlier maturing cash crops
Corn silage, popcorn
Plant green

Cereal rye interseeded into corn.

Anna Cates, University of Minnesota Extension

A longer growing season means more biomass for cover crops. There are a number of ways to extend the cover crop growing season.

Flying on cover crop seed. Commonly done in corn and soybeans once they begin changing color in early fall. More light penetrates the canopy and cover crops can get a head start. Getting a rain soon after aerial seeding is important.
Interseeding is a practice still being perfected. Cover crops are seeded at the V6 or V7 stage of corn (before canopy closure) aerially, broadcast, or with modified high-boys. Cover crops have some time to get started before canopy closure, then start growing again in the fall when the canopy opens up again.
Planting green allows for later termination and more spring cover crop biomass. Cash crops are planted into standing, green cover crop. The cover is terminated with a roller-crimper or herbicide and the cash crop emerges through the residue.
Early maturing cash crops: Some farmers use earlier-maturing varieties of cash crops as a way of managing risk. Eking out an extra bushel or two while worrying about winter weather and not having time to establish a cover crop is stressful. Planting varieties that mature a few weeks earlier gives cover crops more time to get established for grazing. The extra biomass on the cover crop may justify the potential (small) yield loss.
Alternative crops may have shorter growing seasons that allow for more a longer cover crop season. Silage corn and popcorn are two examples.

Image: https://fyi.extension.wisc.edu/sustag/2013/02/19/building-a-better-system-with-no-till-and-cover-crops/

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Maximize grazing potential

Managing cover crops for grazing

Picking cover crop species and variety

Nutritive Value

Yield

Regrazing potential

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Maximize grazing potential

Managing cover crops for grazing
Picking cover crop species
Mixes

Reduces risk

Cover crop failure
Toxicity

Better animal nutrition
Soil health

Lindquist, MSU Extension

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Grasses

Rob Kallenbach, University of Missouri

	Average daily gain	Total Gain
Small grain	lb/day	lb/acre
Wheat	1.8	180
Cereal Rye	1.6	336
Annual ryegrass	1.8	511

The most common and forgiving cover crops can provide valuable forage

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Grass options: cool-season

Cereal rye- Reliable, easy to establish

Winter wheat- Keeps palatability later in spring

Triticale- similar to cereal rye and winter wheat

Barley- Low lignin content

Oats- Good fall growth, does not overwinter

Edwin Remsberg- SARE

Annual ryegrass- Retains green tissue most of the winter

Rapid fall growth
Stockpiles well

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Grass options: warm-season

Corn- Very palatable, more cold tolerant than other warm-season grasses. Inexpensive. No prussic acid

Sorghum- drought and heat tolerant. Lots of biomass, but not regrazable. Can be stockpiled.

Sorghum-sudangrass- Palatable, can graze multiple times. Stockpile potential.

Pearl millet- Can be regrazed. High protein but does not stockpile well. No prussic acid.

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Brassicas

Some species can produce 3 or more tons/acre

Some can grow after frost and overwinter

Tubers can be grazed

High in protein, best if combined with a grass or even hay. <2lb per acre seeding rate

Rob Kallenbach

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Brassica options

Forage radish- fast developing

Turnips- leaves and tuber consumed

Canola- overwinters, can be regrazed

Kale- very cold-hardy, retains quality late into winter

Edwin Remsberg, SARE

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Legumes

Excellent nutritive value

Do not tolerate heavy grazing well

Slow fall growth

Potential for bloat if they make up too much of some livestock’s diet

Rob Kallenbach

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Legume options: clovers

Crimson clover- some varieties are more winter hardy than others

Red clover- can be harder to terminate, but very winter hardy

White clover- can tolerate heavy grazing

Berseem clover- as good quality as alfalfa, but not winter-hardy

Balansa clover- cold hardy and heat tolerant. Hollow stems make better quality at maturity

Edwin Remsberg SARE

MS State Extension

Crimson Clover

Balansa Clover

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Legume options: other cool-seasons

Austrian winter pea- consider white flowered varieties with less hard seed

Hairy Vetch – can be toxic to cattle and horses, especially black angus. Keep at <10% of stand

Common vetch- tolerates grazing fairly well

Medics- only fair forage value. May have antibiotic and antifungal effects

NRCS

Hairy vetch

Austrian winter pea

NRCS

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Legume options: warm-season

Sunn hemp- fast growing (~6ft by 60 days). Will regrow if lightly grazed
Soybeans- originally a forage crop.
Cowpeas- reliable, heat-adapted legume. Can regrow after grazing if planted early
Mung bean- similar to cowpea, but faster growing and more drought tolerant

LSU AgCenter

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Other broadleaf options

Broadleafs: Best used in mixes

Sunflower- produces lots of biomass in short season
Okra- contains high levels of vitamins
Flax- low fertility needs and hardy, but not very palatable. Best in a mix
Buckwheat- fast emerging and growing. Can cause photosensitivity if it makes up >30% of forage
Safflower- Very palatable until maturity. Use spineless varieties

Rob Myers

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Toxins: nitrates

Grasses, brassicas, and legumes can accumulate dangererous levels of nitrates during and after period of plant stress

Use cover crop mixtures with plants from different families
Avoid grazing 5 days after drought ends or after frost
Manage grazing to allow to keep animals consuming upper plant parts (nitrates tend to accumulates in grass stems)

Dennis Hancock, UGA Extension

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Toxins: prussic acid

Sorghum-related grasses accumulate prussic acid in leaves during drought and after a non-killing freeze

Wait until 18-24 inches to graze, includes regrowth

Avoid grazing for 5 days after frost

Keep animals off drought stressed plants

Include non-sorghum species in mix

University of Minnesota Extension

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Redesigning cropping systems

Profit- income from livestock can more than replace lost crop revenue from lower value crops

Revenue Diversification- reduces risk and income variability

Synergy- livestock health can benefit from grazing high quality cover crop forage. Soil health improves faster with animals in the system = better and/or more consistent crop yields

Livestock and row crop operations are much less integrated today than in the past largely due to economic forces and industrialized agriculture.

Cover crops provide an opportunity to integrate livestock and row crop operations. Doing so can lead to higher, less variable profits and a more sustainable farming enterprise. But maximizing the profitability of an integrated livestock and row crop system requires redesigning cash crop rotations and forage systems. Key factors to focus on are:

Profit over yield:

Risk management and stability: Farm income diversification, in this case livestock and row crop income, can reduce the risk of major losses since livestock and commodity prices tend to be negatively correlated

Synergy- using cover crops to integrate livestock and row-crops not just adds the profits of one to the other, it can improve the profits of each. Livestock grazing on lush cover crops can be healthier and more productive than in a traditional system that relies on stored forage for part of the year. Commodity crop yields can also increase from the soil health benefits that livestock manure and grazing action provides.

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Redesigning cropping systems

Use cover crops to fill forage gaps in perennial systems

summer slump: warm-season cover crops after a small grain or winter pea

winter- stockpiled warm-season covers and/or cool season cover crops

UGA Extension Bulletin 1351

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Redesigning cropping systems

Adding small grains to corn/soybean rotation

Creates opportunity to graze warm-season cover crops

Can fill summer forage gap

Alleviate fescue toxicosis

Sorghum-sudan grass and sunnhemp

Rob Myers

Mix after wheat

Joe LaRose

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Grazing economics

Factors that influence grazing economics:

Infrastructure costs (fencing, water)
Type of livestock operation
Cover crop seed costs
Establishment costs
Cover crop growth
Cost-share

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Economics examples

SARE Cover Crop Economics

Calculated a $49.23 per acre annual return from grazing cover crops

Assumptions:

Cereal rye generates 1500 lbs. dry matter/acre
50% of rye biomass is lost from hoof action & selective grazing
750 lbs./acre of rye replaces 1093 lbs./acre of hay when 78% of hay is utilized and hay is 88% dry weight
Hay is valued at $80/ton
Savings of $5.50 per acre for reduced machinery, fuel, and labor costs from not hauling hay
Portable electric fencing and water are available

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Economics examples

Practical Farmers of Iowa

Cereal rye, wheat, or triticale seeded in early September produced 0.07-0.47 tons/per

Hay replacement = $6.22 - $41.78 per acre

Winter covers following rye or wheat, planted early August, produced 1.76-3.74 tons/acre

Hay replacement: $156.44 - $332.44 per acre

Mixes of grasses and brassicas produced between 0.19-3.81 tons/acre

Hay replacement = $8.00 - $338.67 per acre

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Economics examples

Pasture Project

North Dakota- steers grazed for 31 days on cool season covers interseeded into corn at V6. Net profit was $185.85 per acre.

Minnesota- stockers grazed cover crop following winter wheat. Net profit $153 per acre.

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Leases

There are many ways of doing cover crop leases, but there are some common factors to consider:

Cost of cover crop seed and establishment

Fencing- clarify ownership and maintenance

Forage yield and value

Grazing time

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Rental rate example

Fee per acre
Fee per lb of gain (performance)
Animal Unit Month (AUM) method

Sedivec and Meehan, 2019. R1823 Determining Pasture Rental Rates. https://www.ag.ndsu.edu/publications/livestock/determining-pasture-rental-rates#section-13

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Overlooked benefits: calving

Healthier winter/spring calves on cover crops

“Cleaner”, less mud and disease

Nutrition: high quality forage available for lactating cows

Jason Johnson, USDA-NRCS, Iowa

David Cope

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Overlooked benefits: wildlife

Less slug and vole problems by removing some plant residue

Wildlife

Birds can benefit from more varied plant heights that result from grazing
Dung beetles and other beneficial insects

Nick Sloff

Anne Fischer, NRCS

MU Extension

Dung beetle: NRCS Anne Fischer

Bird- University of Missouri

An unexpected benefit of grazing cover crops might be helping with two of the major pests of no-tilled cover crop fields: slugs and voles.

Slugs thrive in moist conditions protected by lots of plant residue, which often happens in no-tilled fields with a thick cover crop. Grazing reduces the residue that slugs live in
Voles are more common with lots of canopy cover from a good cover crop stand. Grazing cover crops in the spring would eliminate some of the canopy cover, exposing voles to predators.

Wildlife

Dung beetles and any of the numerous invertebrates that help recycle nutrients in livestock waste will definitely benefit from grazing cover crops.
Some bird and insect species may also benefit from the more complex and varied vegetation structure that happens after grazing, assuming the cover crop is not grazed to the ground.

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Summary

Grazing cover crops can be profitable for row crop operations and livestock operations

Often perceived to be more complicated than it is

Beneficial for soil health if proper grazing techniques are used

Create opportunity to diversify cropping systems and fill gaps in forage availability