What About Dragging Pastures?
By: Jim Gerrish, Forage Systems Research Center
-- Linneus, MO
BOARD OF DIRECTORS: Greg Kerr-President, Fiver Falls; Doug Bastian-Vice President, Madison; Dan Undersander-Exec Secretary-Treasurer,
Madison; Ken Barnett Wausau; Tom Braun Reedsville, Darell Christensen Brownsville, Robert Eder New London; Matt Hanson Jefferson, Jake Kaderly Monticello, Randy Knapp Chippewa Falls, Ken Risler Mondovi, Scott Schultz Loyal, Paul Sedlacek Cadott; Ex-officio: Dennis
Cosgrove River Falls and Keith
Kelling Madison.
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elcome to the Summer 1999 Forager. Our second mild winter in a row has meant very little winterkill in
Wisconsin. Another early spring is resulting in good first crop yields across
the state. An extended period of rain has pushed first crop cutting back in
some areas of the state, however, so quality may be less than desired.
The PEAQ system for
determining alfalfa quality and timing of first cutting was used in Wisconsin a
great deal this spring. Changes in the
PEAQ equation have resulted in improved correlations between PEAQ predictions
of quality and NIR results. More information on the PEAQ system may be found on
the UW-Forage home page at www.uwex.edu/ces/forage.
Make plans now to attend the Wisconsin Forage
Council Forage Expo September 8 in Manitowoc County. A good show is being
planned, and we hope to see you there.
(See insert for more information.)
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UPCOMING EVENTS |
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September 8, 1999 |
WFC Forage Expo – Manitowoc, WI |
January 25 & 26, 2000 |
WFC Symposium & Annual Meeting – Wisconsin Dells, WI |
July 2000 |
American Forage & Grassland Council Annual Meeting –Madison, WI |
IN THIS ISSUE
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Page
2 |
A
New Use For Alfalfa |
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Pages
3 & 4 |
What
About Dragging Pastures? |
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Page
4 |
New
Director at USDA Dairy Forage Research Center |
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Page
5 |
Managing
Hail Damaged Alfalfa and Red Clover |
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Page
6 |
Wisconsin
Forage Council Advertising |
Buildup of phosphorus (P) in the environment and the
resulting degradation of water resources is of mounting concern. High P levels
in lakes and streams cause increased growth of aquatic plant life such as
algae, which reduces the quality of these waters for wildlife and recreation.
Much of the increase in P levels are a result of human activities including
livestock production. P is abundant in the grain-based rations of poultry and
swine. Because much of the P in grain is present in insoluble compounds called
phytates, monogastric animals such as these are able to absorb only about
one-third of the total P present in their rations. As a consequence, rations
must be supplemented with inorganic forms of P such as dicalcium phosphate in
order to meet animal nutritional requirements. This practice involves additional
cost, and results in excessive P being added to the environment.
Research has shown that the addition of an enzyme
known as phytase to rations of monogastric animals can nearly double the amount
of P derived from grain. This can reduce or eliminate the need for P supplementation,
and reduce the P content of the feces by up to 50 percent.
The phytase enzyme is produced by a fungi, and is obtained through fermentation in large vats. Currently, the cost of phytase supplementation is higher than the cost of conventional P supplementation with dicalcium phosphate. In order to reduce the cost of phytase supplementation, a team of researchers at the USDA Dairy Forage Research Center have produced transgenic lines of alfalfa which are capable of producing the phytase enzyme. Several of these lines were recently evaluated for their ability to produce phytase in the field. Using a value of $3.00/ton for inorganic P supplementation, the value of the phytase produced by these lines was $1500 to $1890 /acre depending on the extraction method. Further work showed that use of this extract in chick and weanling pig rations resulted in gains which were equal to or greater than those obtained from P supplementation, or from use of commercial phytase extracts.
The use of transgenic alfalfa lines to produce
phytase enzymes has potential both to reduce the cost of P supplementation, and
to reduce environmental problems associated with swine and poultry production.
It may also represent the beginning of many new uses of alfalfa as a “plant
bioreactor” for producing many different compounds.
References:
Koegel,
R.G, et.al. Phytase Feed Supplements from Transgenic Alfalfa. U.S. Dairy Forage
Research Center 1998 Research Summaries.
Koegel,
R.G, et.al. Feeding Trials Involving
Transgenic Alfalfa Phytase. U.S. Dairy Forage Research Center 1998
Research Summaries.
What About Dragging Pastures?
By: Jim Gerrish, Forage Systems Research Center
-- Linneus, MO
One of the questions that I commonly hear at
producer meetings is: "Does it do any good to drag pastures?" My
usual answer is the universal extension answer for all questions, "It
depends!" and that is usually followed by my question, "What are you
trying to accomplish?" Someday
when you have a lot of time on your hands, think about all of the things you do
during a day, and ask yourself what you are trying to accomplish with each
task. The result may be a little scary.
What are we trying to accomplish with dragging
pastures? The most common goal is to spread manure piles to accelerate manure
decomposition and enhance nutrient cycling. Covering seed or disturbing a
thatch layer are other common objectives. Dispersing manure piles may also lead
to more uniform grazing. On some farms, dragging pastures is a tool to transfer
funds to dependent children in a tax deductible manner.
Does dragging to scatter manure piles actually
enhance nutrient cycling? For all practical purposes, no research exists to answer
this question. From high school chemistry or building a campfire, we know
intuitively that as particle size decreases, rate of reaction increases. Thus,
if manure piles are reduced to manure fragments, they will decompose more
quickly. The smaller particles also have greater surface area contact with the
reactive surface (ie. the soil). I believe it is a pretty safe assumption that
nutrient cycling is accelerated following dragging.
The next question is, is the rate of increase in
nutrient cycling economically meaningful? I really haven't a clue whether it is
or not. Some other aspects of dragging pastures may have economic relevance.
The chain or flex type harrow is a very useful tool for bringing overseeded
legumes or grass into better contact with the soil. The greater likelihood of
the overseeded crop establishing is probably worth the cost of dragging. Manure
dispersal comes as an added benefit.
Spotty grazing is very often the result of livestock
avoiding manure piles. Scattering those piles can lead to more uniform regrowth
and less selective grazing. To completely avoid manure-induced spot grazing is
virtually impossible with any class of livestock which are in a production
mode. Dragging pastures after every grazing period to avoid spot grazing is
probably not economically feasible.
Timing of dragging can be fairly critical. Autumn
dragging to break piles up going into the winter can result in much more even
growth on pastures which do not receive nitrogen fertilizer. Nutrients
contained in the manure are likely to be back into the soil solution for early
spring growth if autumn harrowed. Manure piles that have dried a few months
tend to shatter and scatter very nicely this time of the year. It also ensures
that legume seeds contained in dung piles are more likely to come into soil
contact in the spring.
Spring harrowing can either accelerate or slow
pasture growth rate in the spring. Harrowing prior to or at green-up frequently
accelerates pasture growth by disturbing the thatch layer and allowing the soil
to warm up more quickly. We have measured three to five degree differences in
soil temperature in side by side harrowed and unharrowed strips in early
spring. But, if harrowing is delayed too long after early green-up, growth rate
can actually be slowed due to damage to tender young plant growth. Delaying dragging
too long in the spring can also result in destroying legume seedling growing on
dung piles.
Some concern has been expressed that dragging pastures
may increase the likelihood of spreading infection of intestinal parasites to
grazing animals. While this may be a concern in some environments, it is
generally not considered to be a problem in the Midwest and Upper South. Manure
in dragged pastures dry out very quickly during most of the year (May to October)
in Missouri. Exposing more manure surface area to the sterilizing effects of
solar radiation kills most parasites. Simply drying the manure out reduces the
likelihood of some survival for some organisms. In cooler, cloudy climates,
parasite persistence is much more of a problem. Parasite re-infection due to
dragging is also more likely to occur with horses than with cattle due to the
very severe overgrazing habits of set stocked horses.
We have kicked the piles around and thought about
some of the benefits of dragging pastures. It is very difficult to say whether
or not the benefits of dragging are worth the cost of doing it. In terms of economic
importance, I would rate the benefits in the following order: reduced spot
grazing (enhanced utilization rate is the economic benefit); improved seed/soil
contact (the economic benefit is improved pasture productivity; and accelerated
manure decomposition (the economic benefit is reduced fertilizer input).
On March 1, 1999, Dr. Neal Martin became director of the USDA Dairy Forage Research Center in Prairie du Sac, WI. Dr. Martin replaces Dr. Larry Satter who served as director for 11 years, and returned to full-time research in 1997, and Dr. Dick Smith who served as interim director in 1998. Dr. Martin comes to Wisconsin from the University of Minnesota where he served as Extension Forage Agronomist for many years. He was instrumental in starting the Minnesota Forage and Grassland Council, and has been involved in many areas of forage research, including efforts aimed at improving NIRS forage testing procedures.
Those of us involved in forage research and
extension in Wisconsin have enjoyed an excellent working relationship with Neal
during his years in Minnesota, and look forward to working more closely with
him now that he has come to Wisconsin.
Hail damage of alfalfa and red clover occurs in
varying degrees of severity ranging from some terminal bud and leaf damage, to
completely defoliated plants. Stands may also be lodged by accompanying wind
and rain.
Alfalfa and red clover grow from the terminal (highest) portions of the plant. If these are damaged, growth is stopped on that stem. Thus, loss occurs from physical removal (loss) of forage and from terminated growth, requiring the plant to begin new shoots (stems) for growth.
Yield losses from any percentage defoliation will be
in relation to the total undamaged yield potential. Data collected at
UW-Marshfield Research Agricultural Station by Dan Wiersma suggests
that forage losses for hail damage to first cutting
will be approximately 35 lb dry matter per acre for each percentage defoliation
occurring with two weeks of harvest for both alfalfa and red clover.
This occurred on stands where the undamaged yield
was 2.25 t/a. Hail damage losses for later cuttings are the same for alfalfa,
and 23 lb dry matter for each percent defoliation of red clover occurring
within two weeks of harvest. Actual losses are lower for second or third
harvests since undamaged yield will be typically lower for these cuttings.
Forage quality losses also occur since the top and
highest quality portions of the plant are removed when hail defoliates a plant.
However, these losses are small.
Hail damage occurring earlier than two weeks before
harvest will generally be to plants short enough so that the crown is exposed
to some light. These plants will put out new shoots and produce a hay crop,
though somewhat delayed.
When harvesting lodged alfalfa or red clover, our
experience has been that disc mowers will pick up more forage than sickle bar
mowers. Harvesting against the direction the forage is leaning will allow more
to be harvested. With both mower types, tilt the cutter bar or discs forward to
increase forage picked up. When using a sickle bar mower, one can additionally
move the reel forward and down and increase reel speed to help pick up downed
forage.
Recommendations
are:
1.
If
alfalfa or red clover is within two weeks of harvest and lodged, wait 3 to 4
days to allow stand to recover and harvest.
2.
If
alfalfa or red clover is within two weeks of harvest but less than 50% of terminal
buds are damaged, allow stands to mature to normal harvest schedule and
harvest. Yield will be reduced, but undamaged buds will continue to grow and
produce additional yield.
3.
If
alfalfa or red clover is within two weeks of harvest but greater than 50% of
terminal buds damaged, harvest immediately because little additional growth
will occur (to the extent that terminal buds have been destroyed) except that
coming from new stems, which could be a part of the next regrowth.
4.
If
alfalfa or red clover is not within two weeks of harvest (stand generally 12
inches or less tall), wait for stand to re-grow from new shoots and harvest
when forage is at normal harvest height and quality.
Do you have a forage-related service, forage equipment or forage (hay,
haylage or straw) you would like to advertise for sale? If you do, the Wisconsin Forage Council is offering, as a service
to our members only, the opportunity for you to advertise in The Forager. For a small fee of $5.00 for each issue you to plan to advertise
in, you can place your ad in up-coming issues of The Forager.
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