Ag Connection
Your link to the Universities for ag extension and research information


Volume 5, Number 5
May 1999
 

 

This Month in Ag Connection

Amber Waves of Bromesedge
Birdsfoot Trefoil Update
Rules of Thumb for Managed Grazing
Watson's Thoughts on Balage
Grazing Videos Available
Alfalfa Management — A 12-Month Calendar

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Amber Waves of Bromesedge

Many pastures in late winter and early spring have an amber wave, but it is not grain — it's bromesedge. Bromesedge, or broomsedge as it is commonly called, is not a sedge but is a member of the grass family. The vegetative portion grows close to the ground and produces curly, light green leaves. When the plant goes reproductive, it produces a golden stem that was often cut, bound and used as a broom. While it appears to have been productive in the reproductive stage, its actual forage quality is low. Nutritive value for grazing animals is practically zero.

Understanding the cause or causes of the encroachment of broomsedge will aid in the treatment and control of the broomsedge problem. A pasture is an ecosystem dominated by desirable grasses and legumes with a few trees and shrubs. The balance of this system is determined by abiotic and biotic factors. Abiotic factors include available water, light, nutrients, temperature and fire. Biotic factors include grazing pressure, disease, and insects.

Managing a pasture ecosystem requires balancing both abiotic and biotic factors. If these factors fall out of balance, desirable forage species are lost and replaced by less or undesirable ones such as broomsedge.

Invasion by broomsedge can mainly be attributed to two of the above factors: low nutrient levels in the soil (soil fertility), and excessive grazing pressure. Broomsedge tends to thrive in soils with a low pH (< 5.5) and low levels of phosphorus (< 30 lbs./acre). At these soil fertility levels, desirable forage species will not survive under grazing and haying pressure. As a desirable forage plant dies, it leaves a void in the canopy, allowing additional light to penetrate the canopy and setting up an environment suitable for the germination and propagation of broomsedge.

Close grazing adds to the problem. Grazing animals avoid eating broomsedge. This means desired grasses and legumes are being nipped off every seven or eight days. This shifts the environmental factors in favor of the broomsedge. Allow this scenario of intense grazing pressure and low soil fertility to go on for several years and we have the broomsedge explosion that we now see.

How do we fix the problem?

Don't go in search of a silver bullet — in this case chemical control. Broomsedge is not competitive in a well-managed pasture. Begin with a simple soil test.
Look at pH and phosphorus levels in particular, but do not ignore other nutrients. If lime and phosphorus are required and you have a limited soil fertility budget, begin with lime.
Work the phosphorus level up. Phosphorus is extremely important for maintaining legumes in the pasture. It is also used in making of the "energy currency" of plants (moving energy throughout the plant). Poultry litter is a good source of phosphorus as well as organic nitrogen. If it is available in your area, it might be worth exploring. Use caution when pricing poultry litter. Price it on a ‘cost of nutrient’ basis. What might appear to be cheap fertilizer may be high if the concentration of nutrients is low.
Evaluate your grazing strategy. If all your pasture grasses underneath that golden canopy of broomsedge are maintained at a height of less than 4 inches, seriously look at the reasons why and what can be done to enhance plant competition.
Does burning help? Fire does improve the forage quality of a pasture. Regrowth after a burn will be higher quality than what was burned. However, continued use of fire in cool season pastures will eventually reduce the desired grasses. Broomsedge is a warm season grass and is not damaged by early spring fires.
Does mowing help? Probably not, due to the growth habit of broomsedge. By the time it gets high enough to mow it has reached the reproductive stage. Hence mowing probably aids in seed distribution.
What about herbicides? Any herbicide that would have activity on broomsedge would also damage the desirable forages. A selective application (spot spraying, weed wiping) that targets the broomsedge, but is not applied to the desirable forages, may be possible.
Be patient. It will take some time to gain control of broomsedge. Over the long run, changes to your management program will be rewarded by increased forage productivity and grazing days.

Author: James Rogers, Livestock Specialist



For more information, see UMC Guide
G4640 — Birdsfoot Trefoil
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Birdsfoot Trefoil Update

A USDA researcher at the University of Missouri made everyone proud a couple of years ago by introducing a major new improvement to a great forage. It was "Steadfast" birdsfoot trefoil. Now this long-lived perennial legume had even more long-lived characteristics.

Paul Beuselink combined attributes from current trefoil varieties with a type of trefoil from Morocco. The Moroccan trefoil had rhizomes. This gave Steadfast the ability to spread by its roots as well as seed. Plantings of this rhizomonous birdsfoot trefoil will be able to sustain and increase stands. Another advantage should be Steadfast's ability to survive intense grazing. This was a factor in the selections from Morocco where intense overgrazing is the normal situation.

This may start to sound like a good news, bad news joke. Unfortunately, plans by Peterson Seed Company of Savage, Minnesota to begin commercial distribution of Steadfast seed in 1999 have been delayed until the year 2000. (Maybe it is a Y2K problem.)

Beuselink's advice is not to wait. There are several excellent varieties available now. Three forage varieties are Norcen, AU-Dewey, and Dawn. They all have the characteristics that makes birdsfoot trefoil a great forage — like nitrogen fixation, no bloating risk, and high levels of nutrients in its leaves and palatable stems. Norcen is a semi-erect variety with good yields and excellent winter hardiness. More adapted to southern conditions, AU-Dewey is also a semi-erect variety that grows well in Missouri. Dawn, another semi-erect variety has fine stems, good yielding abilities, excellent fall growth and tolerates grazing well.

One simple management tool is giving these birdsfoot trefoils a rest period at the end of the grazing season for flowering and reseeding. This allows the stands to increase or sustain themselves without the benefit of rhizomes. Two erect hay types are Maitland and Viking.

Author: Jim Jarman, Agronomy Specialist 




Grazing Video's AvailableGrazing Videos Available

Interested in learning more about intensive grazing? Ten videos are now available for loan through your local Extension Center. These tapes were produced by the UMC Forage Systems Research Center. 

Tapes now available include:

  • Optimizing Plant Growth
  • Meeting Nutritional Needs of Livestock on Pasture
  • Designing a Manageable System
  • Extending the Grazing Season
  • Forages for Summer Grazing
  • Soil Nutrient Management in Pastures
  • Water Systems Development for Grazing Systems
  • Appropriate Supplementation on Pasture
  • Matching Livestock and Forage Production Cycles
  • Fencing Systems for Grazing Management

Tapes range in length from 10 to 20 minutes, and can be checked out or may be viewed at the extension center. Contact your University of Missouri Extension Center for more information.

 

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Rules of Thumb for Managed Grazing

Animal performance on pasture is determined by voluntary forage intake. Intake is determined by forage availability and quality. Managed grazing strikes a compromise between these two factors.

Length of paddock rest affects plant health, vigor, regrowth, and the subsequent quality and availability of forage.

Grazing height affects intake, regrowth, total production, plant vigor, root system, soil erosion, water efficiency, and wildlife.

Stocking density affects the length of the grazing period, forage utilization, and manure distribution.

Rest Periods:

Cool Season Grasses:

14 - 16 days during fast growth (spring months)
30 - 40 days during slow growth (summer months)
20 - 30 days during the fall months

Legumes:

24 - 32 days throughout the grazing season

Warm Season Grasses:

14 - 21 days during early fast growth
21 - 28 days during normal growing conditions
35 - 45 days during slower growth conditions
45 - 60 days during adverse weather (drought)

Native Warm Season Grasses:

30 - 45 days during normal growing conditions
45 - 60 days during adverse weather

Grazing Periods:
The faster the growth the shorter the grazing period:

3 - 5 days maximum in spring
5 - 9 days maximum during early summer
9 - 12 days in late summer
5 - 9 days during fall

For optimal animal performance:

Dairy cattle - move 1 - 2 times per day
Stocker cattle - move every 1 - 2 days
Cow/Calf - move every 2 - 5 days

Author: Parman R. Green, Farm Management Specialist, Source: "Management Intensive Grazing


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Watson's Thoughts on Balage

Balage is an excellent method of harvesting forages and can help you save forage quality, especially under inclement weather conditions.

Advantages

Virtually all forages can be harvested as balage
Legume or legume-grass mixtures are excellent sources for this method
Harvest at optimal stage of maturity regardless of weather
Easier to attain 50% dry matter compared to 18% dry matter
Reduces field leaf loss and provides more available nutrients for feeding
Provides a nutritious palatable feed and requires no additional processing
Provides a consistent forage for the feeding period
Yields can be increased
Spoilage and feeding losses can be reduced

Disadvantages

Increased weight of the bales due to moisture content
Plastic wrapped bales must remain sealed to prevent spoilage
Feeding in bunks or rings is recommended to reduce waste
Off farm market is limited
Transportation cost is increased
Additional equipment is required for wrapping and handling
Plastic must be disposed of
Costs may be higher than other methods of harvesting

Author: Dale G Watson, Livestock Specialist/Commercial AG Beef




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Alfalfa Management — A 12 Month Calendar

General —

  • Always soil test several months before seeding.
  • Work lime into soil at least 6 months prior to seeding if pH is less than 5.5.
  • Stand densities below 3 plants per square foot are considered uneconomical to maintain and need to be renovated.

January — Do not use your alfalfa field for winter grazing. Soil test every 3-4 years for topdress recommendations. Begin planning your marketing strategy. Resources include the Missouri Department of Agriculture Hay Directory which you can call at 1-800-877-4HAYor access on the Internet at http://agebb.missouri.edu/haylst.

February — Topdress according to soil test since each ton of alfalfa removes 10 lbs./acre of phosphate and 45 lbs./acre potash. Add 1 pound of boron per acre each year. If your alfalfa stand is getting thin, five pounds of medium red clover can be seeded.

March — Plant alfalfa (15 lbs./acre) alone or alfalfa (12-15 lbs./acre) plus orchardgrass (2-3 lbs./acre). Use only certified well-adapted seed. Be sure to use alfalfa seed inoculant.

April — Make pure seeding of alfalfa using Balan or Eptam herbicide. Scout for alfalfa weevil and use early grazing or spray for control if needed. Observe fields for bud development to estimate the time of first cutting. Best compromise for yield and quality is to begin harvest at 1/10 bloom.

May — Top-dress after first cutting, if not done in February. Watch for additional weevil damage and variegated cutworms.

June — Cut alfalfa for second time, 30-35 days after first cutting. Watch for leafhopper damage.

July — Graze if regrowth is insufficient to justify cutting for hay. Chance of bloat is very slight if alfalfa is dry and starting to bloom.

August — Plant alfalfa (15 lbs./acre) or alfalfa (12-15 lbs./acre) plus orchardgrass (2-3 lbs./acre) from August 15 to September 15. Seeding depth should only be 1/4" to ". No herbicide needed for tilled seedbeds. Scout and control grasshoppers as needed.

September — Make last regular cutting no later than September 15 or yield and stand will be reduced for later years. Add fertilizer if hay yields exceeded fertilizer used during the year. Plant red clover or orchardgrass if stand is thinning.

October — Do not cut or graze or harvest in any way.

November — Make dormant cutting or graze after heavy frost or freeze.

December — Spray for winter annual weeds using any of the labeled products such as Gramoxone, Sencor/Lexone, Sinbar or Velpar. Spraying can double returns. Always read and follow label directions.

Author: Oscar Ingram, Agronomy Specialist, Webster County

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University of Missouri ExtensionAg Connection - May 1999
http://outreach.missouri.edu/agconnection/newsletters/is-99-05.htm -- Revised: April 20, 2004
daydr
@missouri.edu