| June
8, 2006: As an all grass, no-grain dairy, we pay
close attention to our grazing. Our experience with transitioning
from management intensive grazing (MIG) to Holistic Management
planned grazing on Cimarron Farm has been rewarding. I am
confident that planned grazing gives us the best results possible,
and things just keep getting better. Some benefits that should
be noted up front include:
- Everybody on the farm enjoys taking a few days during
the cold of winter to contribute to a plan that they can
see and work with through the whole season.
- The cattle end up where they are supposed to be, when
they are supposed to be there. Thinking through the year
beforehand often opens up new possibilities that we hadn’t
considered previously.
- We don’t “run out of grass” or commit
what Andre Voisin termed “untoward acceleration”
during slow growth periods, as we have planned moves based
on slow growth. (“Untoward acceleration” is
the situation where each successive grazing period provides
less forage, and the recovery period is thus successively
shortened until most plants in most paddocks are overgrazed
and there is no feed left.)
- Animal performance keeps improving, and recovery periods
keep decreasing.
- Grazing planning is a great way to “enter the mind
of the land”….we approach it like a game of
biological chess in which everyone wins.
The basic ecological principles outlined in Holistic Management
have also led us to experiment with some grazing and soil-building
strategies that differ from management-intensive grazing convention
in these parts. The results have been encouraging and are
the main subject of this article.
I will qualify what follows by noting that we are located
in non-brittle Vermont, we are running cows (about 70 mature
cows and 40 young stock, this year) and this farm was rotationally
grazed for 20 years prior to planning our grazing. I write
in the spirit of experimentation. We have made changes in
management that have yielded positive results. We are still
monitoring!
Grazing tall improves forage, topsoil
and growth rates
The standard advice in management intensive grazing circles
is to graze 4- to 8-inch (100-200 mm) pastures down to 1-3
inches (25-75 mm). Reasons offered include even re-growth,
high digestibility, high protein for high milk and meat production,
avoidance of pokey stems causing pink-eye, higher clover content
due to less light competition and better water cycling due
to less leaf transpiration.
This strategy comes with built-in problems. Our challenge
in lush pasture grazing is to provide enough energy to balance
the very high levels of “protein,” including non-protein
nitrogen. When stock are forced to eat short, lush, high-protein
pasture, the microbes in the gut still need to get energy
from somewhere, so amino acids, proteins, etc., are deaminized
to get at the energy stored in underlying carbon bonds (i.e.
protein is turned into energy). Energy is freed up, but the
cost is ammonia which is toxic to the animal, and which the
liver and kidneys are forced to deal with. It takes a lot
of energy to run those filters. Additionally, oxygen in the
blood is replaced by ammonia, in effect leading to oxygen
starvation.
Mark Bader, of Free Choice Enterprises, was the first to
alert us to the fact that by grazing very lush pasture, we
were creating alkalosis in the herd. The smell of ammonia
in the milking parlor was very strong, and the manure was
similar to green paint.
Classic pasture dynamics writer Andre Voisin also warned
about the dangers of non-protein nitrogen in Grass
Productivity. Nutritionist Jerry Brunetti of Agri-Dynamics
helps grass farmers manage for forage that minimizes “funny
protein.”
To counter the negative effects of low fiber and alkalosis
that result from grazing such immature pasture, most producers
around here feed supplemental hay, silage and grain during
the grazing season. Having chosen to pursue the all-pasture
path, we determined to figure out how to better meet the nutritional
needs of the stock entirely in the pasture. This led us to
experiment with “grazing tall.” (We should note
that we do feed free-choice minerals, as well as supplement
apple-cider vinegar at the rate of 2-3 oz/head/day in the
drinking water.) For more information on the benefits of cider
vinegar as a supplement for livestock, see D.C. Jarvis’
book Folk
Medicine.
The increased grass production and enhanced soil biology
benefits of the “grazing tall” strategy, though
not called this, are laid out in the chapter on energy flow
in Holistic
Management by Allan Savory. In practice, we let pasture
grow up to about early boot stage (at least 12 inches tall,
usually taller), graze at high stock density, and leave a
well trampled, high residual (say 4 to 7 inches). We still
generally achieve 55 ADA (animal days per acre per grazing
cycle), but the harvested forage is shifted higher up on the
plant.
This practice keeps growth in the steepest part of the sigmoid
curve (that characterizes the varying growth stages of grass
during the season) rather than repeatedly knocking the grass
back to the bottom, shallow slope of the S-curve. Grazing
tall leaves lots of leaf area to kick-start re-growth through
aboveground energy reserves and photosynthesis.
Our maximum recovery period dropped from 60 days to 45 days
in one year when we began grazing tall. Other factors, such
as spring management, also figured into this.
Roots go deeper, moisture retained
Grazing tall results in much more developed root systems,
deepening the topsoil-building zone and enhancing mineral
cycling. Carbon is deposited deep in the soil both through
root prune-off after grazing, as well as through nightly carbon
exudates from the plant into the rhizosphere.
The greater depth of root development is a plus during dry
spells, as roots can tap deep water in soils. It also leaves
a nice mulch layer that seems to reduce soil drying/evaporation,
so water cycling is generally enhanced.
Malcolm Beck points out that the dense litter that results
from trampled residual also leads to high levels of CO2 from
litter decay in the pasture tangle, which localizes and accelerates
carbon cycling and keeps leaf stomata closed longer and more
often, thus reducing transpiration. This makes sense to us,
and our experience confirms it. (Find more on Beck’s
reasoning at: www.malcolmbeck.com/articles/carboncycle.htm.)
Grazing higher on the sigmoid curve is where we find the
best energy/protein ratio, and it accounts for some of our
better animal performance. With our cooler weather here in
the Northeast, we have fewer problems with lignification than
grass farmers in warmer climes.
Allowing the animals to graze the top portions of the plant
and leave the bottoms also increases the energy levels in
the grazed forage. As the cows happily graze the tops of the
pasture plants, I suspect they are telling us that glucose
levels are highest in the upper portions of the plant, where
photosynthesis is actively occurring.
Grazing at high density (we aim for stock density of between
400-800 animals/acre or 1,000-2,000 animals/ha) tramples most
everything down, and results in even re-growth, not at all
clumpy, even when the grass we turn the animals into is over-mature.
It means a lot of moves in the course of a day, but that is
the best part of our job.
High stock density is not generally used in management intensive
grazing, but we have found it to pay off. Clipping pastures
to deal with “clumpiness” is becoming a dim memory.
Fall management key to spring and summer
growth
Jim Howell’s article on Llewellyn Manske's research
into rangeland ecology at North Dakota State University was
an eye-opener for us (click
here for Howell's article). The realization that the secondary
tillers generated in the fall by a grass plant become lead
tillers in the spring leads us to be cautious with fall/winter
grazing and leave the residual or re-growth, where possible,
so these little tillers stay intact.
Dr. Manske’s research is rich. Like eating an artichoke,
we just keep finding good stuff as we peel away the layers.
Dr. Manske points out that light defoliation after third leaf
development (and well before seedhead formation) in the spring
results in high level of carbon exudates from roots that stimulate
soil life in the rhizosphere, enhancing mineral cycling and
energy flow and promoting accelerated plant growth through
the season. This is very exciting stuff to us and complements
Christine Jones’ illuminating writings on the same subject
(see www.carboncoalition.com.au).
Manske's research shows at least a 40-percent increase in
growing season grassland yield when cool season perennials’
lead tillers are lightly defoliated after third-and-a-half
leaf stage in the spring. That's a lot of extra grass. In
addition to the carbon exudates, grazing after third-leaf-plus,
and before seedhead formation increases tillering.
Ever more so, I am realizing that we have to abandon the
high-production mindset and attend fully to the needs of the
plants and soil dwellers before production and performance
can really begin to climb.
Re-thinking early grazing to create the
wedge
Management intensive grazing recommendations that I have
encountered actually encourage the opposite of the above information.
The MIG advice is to get your animals on pasture way too early,
so forage doesn't get ahead of you, and to set up a “grazing
wedge” that results in properly staggered forage volumes
through your paddocks. For a more detailed explanation, see:
http://agebb.missouri.edu/dairy/grazing/wedge/index.htm.
In translation on many farms, this means that animals hit
the ground very early in the season. Many farmers graze through
every paddock before any substantial growth even occurs, or
start grazing when grass has just “achieved a definite
green color”, and by the time they get to the last paddocks
on the farm they are hitting the grass at a reasonable height.
This knocks back that pesky spring flush of grass and sets
up a grazing wedge, but at a tremendous cost; many plants
in many paddocks are overgrazed at the beginning of the season.
Remember, overgrazing occurs when we stay too long, come
back too soon, or graze too soon after dormancy. If a plant
is grazed that is growing from carbohydrate reserves, rather
than from active photosynthesis, it has been overgrazed.
If the “graze really early” advice is combined
with the advice to graze down to 1-3 inch residual throughout
the rest of the season, the effect is that we bite off the
babies' heads, expecting them to grow into healthy adults,
and then keep them doing arithmetic, rather than multiplication,
for the rest of the season (i.e., they are maintained at the
low, shallow section of the sigmoid curve).
Just waiting longer to turn the animals out in the spring,
though, can lead to the troubles of a big winter hay bill,
low nutritional levels late in the cows’ pregnancy (we
calve in the spring), no grazing wedge and many acres of low-value,
over-mature feed. There are many creative ways to address
this.
One way we have stumbled onto grew from thinking through
step five in the Holistic Management grazing planning aid
memoir: note and address unfavorable grazing patterns. What
we are working with now is setting up our grazing wedge the
fall before by allowing substantial re-growth in some paddocks,
higher residual in others, and a normal graze-down on last
graze in still others. This staggers the carbohydrate reserves
(and the survival of fall tillers) that plants have going
into winter within various paddocks. Spring growth responds
consistently —lots of carbohydrates means early, robust
spring growth.
Since this is all recorded on our last growing season plan,
it is easy to make the following growing season plan with
reference to the record. The result is that we are not forced
to overgraze any plants, we get that necessary grazing wedge,
and we increase overall grass production through the season
on the order of 40 percent and more. From our experience with
this, the gain in grass production manifests itself in increased
plant vigor and growth rates, and even higher plant density.
Winter grazing: a work in progress
Winter grazing has an effect on all of this, but it can
still be accounted for with the grazing plan.
We have not been wildly successful with our winter grazing
yet. We are usually on the bedded pack in the barn by the
end of November. Admittedly, we have been struggling to overcome
the common, profitability-impairing attitude that afflicts
many northeastern graziers: “We can’t winter graze
because…too much snow, delicate cows, diesel is still
cheap, we like supporting feed suppliers, we love making hay…etc.”
This doesn't mean winter grazing, and attendant planning,
is not a good idea. We just haven't done much with it yet.
I suspect that when we do, that's when we’ll need a
shovel to deal with the cash flow. (Winter feed and bedding
are our biggest expenses.)
In the recent past our land was overstocked, in that we grazed
much of our summer growth and bought in a lot of hay for the
winter. I suspect that this common strategy for dairy graziers
will not hold up well in the face of decreasing oil supplies.
Toward matching our stocking rate to the carrying capacity
of the farm, we have de-stocked and now carry about 1 animal
to 1.8 acres. We expect that the land will be able to carry
more animals as we build soil health, but we are growing into
it.
Beginning this summer, we plan to experiment with some winter
grazing work. We have the advantage of a new Keyline Flood
Flow irrigation system, which will enable us to have optimal
moisture/ temperature conditions for growing experimental
forage varieties we will be planting this year.
We will be reseeding with improved perennials this year,
with herbal ley ingredients tossed in for good measure, due
to earth work related to the Keyline irrigation system. Experimenting
with varieties that hold up well to winter grazing will be
part of that.
We will also experiment with planting turnips and kale into
close-grazed pasture this year. We expect a beautiful crop
of kale for the cows to graze through the snow once the ground
freezes. In effect, a forage like kale extends the growing
season, and we end up harvesting sunlight through mid-December.
Brassicas also hold their sugar better than perennial grasses
once it gets cold….another contribution to more effective
harvest of solar energy and animal performance. One drawback
worth noting is that brassicas are not effective soil builders
(the fungal associations responsible for the production of
glomalin are not present with brassicas root systems).
The cost benefits of brassicas are substantial, and the energy
input is minimal—especially with zero-tillage (and zero
herbicide) seeding. We have been assured by a few other farmers
that brassicas can be planted successfully into standing pasture
with herd effect, which we achieve daily by strip-grazing
with very small breaks.
Along these lines, it has been illuminating to read Newman
Turner’s Fertility
Pastures (Faber & Faber, 1940). His tried-and-true
strategies for out-wintering dairy cows match and pre-date
our ideas by more than 50 years.
We aim to minimize the energy/money/time investment in stored
forage. Beyond winter grazing, we will be experimenting with
buckraking mowed pastures into vacuum silage clamps early
in the season, when dry hay is hard to make. Later in the
season, we will make loose hay-stacks. Our equipment costs
for transitioning from round bale and wrapping equipment to
old hay loaders, buck rakes and so on has been very affordable…most
equipment has been found in hedgerows and old barns.
We’re early in the development of these ideas, but
we’ll keep folks up to date on progress. 
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