-: Yeah, good afternoon.
Somebody said, "Hello" earlier, and there were
a few people that responded, so that was good.
(laughing)
So, yeah, my good colleagues in the back,
they said, "How did you get 30 minutes?"
And I can't tell you exactly how.
Now, Richard, I guess has told us,
but they weren't sure if it was a
curse or an award.
And they didn't say whether they're cursed
or rewarded with me talking for 30 minutes.
We'll get into it.
Some of you have seen this slide before, I'm certain.
And of course with our theme
of the opportunities and challenges
associated with growth,
Dr. Green has mentioned, and others many times
that a budding challenge and an opportunity
is to see the beef industry grow.
Especially the cow,
especially the cow herd.
So not only the feeding industry with feed yards,
feed lots, but also actually see the cow herd grow
in Nebraska.
And this type of slide is often referred to then,
is Nebraska is uniquely set
to see a growth in the cow herd
and the feeding industry,
because of these integration that's occuring
in terms of corn production or grains in general.
With that grain used in all sorts of rations,
both in feed yards as well as supplemental feed.
And then we have the bio refineries,
which of course produce a bi-product
that's used in feeding livestock,
especially cattle in feed yards and on pasture.
And then of course 50% or more of the state
is in grasslands and ranchlands,
high quality fords production.
So the integration of these things can be seen
as growing the base
for growing a cow herd.
And then, intertwined in all this
is that obviously with growing a lot of corn
there's a lot of stock residue
and someone recently did a survey
of corn fields in Nebraska
and reported that as little as 20-25%
of the stock fields in Nebraska that are
available for dormant season growing
are actually being grazed.
So, that leaves a lot of potential for growth
in terms of dormant season roughage.
And of course not all of this roughage
and stock fields would be grazed.
Lot of it is baled and then fed in pens
or dry lots during the dormant season
to cows or growing animals.
And then Roger reported earlier
on cover crops, and then using those cover crops
as a feed resource or forage
for growing animals or for cows
during the dormant season,
especially in that early fall to early dormant season
period or early winter period.
So, what we're seeing is that with this integration
we're getting more and more roughages, forages
available for grazing or feeding livestock
during the dormant season,
but we're not seeing much relative to the growing season.
And so with this increase in availability and use
of roughages and forages during
the dormant season with increased
stocking rates or increased cattle numbers
that may result
then what happens to our forage resources,
to our grazing lands during the growing season.
Or what typically look at as the grazing season,
from sometime in May to sometime in October.
And of course many of you have seen these figures, too,
maps from an article published in
2011, I believe,
or 2013 that shows the increase conversion of grasslands
to croplands that occurred in the late,
around 2006-2011.
So, not only are we seeing increased cattle numbers
potentially, but also fewer acres of grasslands
to support that during the growing season.
So, what can we do if we do increase the cow herd?
Because of that increased forage availability,
roughage availability during the winter?
So, we are going to look at increased stocking rate,
and simply overgraze during the growing season,
or do we look at increased forage production?
With the grasslands that we have, do we provide inputs
that then increase forage production?
Or do we look at increased harvest efficiency?
Harvesting a higher percent of what's available.
And of course, especially in eastern Nebraska,
on some sub-humid grasslands,
there is opportunity to increase production
because grass breeders continue to produce more,
develop grass varieties
that have increased production potential.
So we can use them.
And such inputs as fertilization has long been documented
will increase forage production.
And then on these eastern Nebraska pastures,
we can look at increased efficiency of use
of what's available,
so we can look at higher stocking rates
because we have simple plant communities
very often dominated by grass like
smooth brome grass.
Those grasses grow rapidly following
defoliation, because there is good soil moisture,
good nutrient availability,
and these are plant types that can tolerate stresses,
especially tolerate high defoliation levels.
So with more efficient use of these grasslands
we can increase the percent that can be defoliated
or grazed during that growing season.
'Course we've moved further west into semi-arid rangelands
like in central and western Nebraska.
These higher stocking rates more efficient use
become much more challenging
because we're dealing with more complex
plant communities and ecological sites.
These are plants that are less responsive to inputs
and then you've got complex plants communities,
so each plant species responds differently
to those inputs.
And overall this system is less tolerant to grazing.
So increasing efficiency, harvest efficiency
and ranglands, semi-arid rangelands
may be more of issue.
But let's just focus on eastern Nebraska pasture
and irrigated pasture, and sub-irrigated pastures
like we have along the Platte River, or in the
sub-irrigated meadows of the Sandhills.
Oops.
So we have a couple
yearlings grazing pastures, sub-irrigated meadow pasture
in the Sandhills,
and what do you notice about.
This would be late June, early July,
these are mostly perennial cool season grasses.
And what do you notice?
What things pop out at you?
It's the patchiness, right?
So, cattle, when they are allowed to select,
when they have more grass than what they need,
they're gonna graze certain areas,
return to those areas as fast as that grass grows
because it's high in nutrient content.
Whereas these areas that have not been grazed previously
and those plants go reproductive,
they get stemmy, they become less palette-able,
lower nutrient density.
And so we get this patchiness which results in what?
Low harvest efficiency.
So from a production perspective,
from Ag production perspective,
all of this is waste.
Wasted, right?
So, we're looking to get a higher percent
of what's available consumed by the animals.
So, how do we do that?
Well, this is probly more of the situation
that a lot of producers like to see
is an evenly grazed area
that there is not that standing material
that's not being utilized, and therefore you should
have a higher harvest efficiency which means
potentially a higher gain per acre, right?
So if we look at this figure, then we've got
improved grazing distribution, so a higher percent
of what's available's being grazed means
then you have increased
harvest efficiency, right?
A higher percent of what's available's being consumed,
which then results in increased carrying capacity,
which leads to, if that's what you want,
higher stocking rates,
higher production per acre.
(mumbles)
So how do we do this?
This has been looked at for decades.
There's many options,
of course location of water is a key.
Most grazing animals are central placed foragers,
and so the center of their universe is water,
so making water readily available
certainly affects how animals
distribute across the landscape.
And there are other tools that can be used
to affect distribution,
but I'm here to talk about grazing management.
So, just real quickly, how do we look at
in that distribution of grazing,
and how can grazing management influence
that distribution of grazing
in how evenly a forage resource is used.
So, most people probly think of grazing
in one context and one context only,
especially those that don't understand grazing,
or against grazing is that
we have cattle spread across a pasture,
they graze the entire area for the five month
grazing season, they select areas
that are favorable to them,
and they overgraze it.
But actually, in these situations,
boy I can't stop hittin' that.
In these situations, then on the top figure,
the cattle are selectively grazing,
they have ready access to that entire pasture
for the five month growing season, let's say, okay?
So it becomes spotty, low harvest efficiency.
So when it's done, in the lower cartoon there then,
concentrate the animals in 1/4 of the area,
and they stay in each pasture for 37-38 days,
something like that.
Divide 150 by 4 pastures,
and so they become more concentrated
in 1/4 of the area
at each pasture
over the entire grazing season.
And if we go ahead and get
a little bit more intense in our management,
we put 16 pastures now in that same management unit,
we concentrate the animals in each one of the pastures,
and now they're going to move
every 10 days or so.
They're more concentrated,
the area within each one of the pastures
is likely going to be less diverse
in terms of species growing, in terms of topography
and so forth.
So those animals within pasture are gonna be
more evenly distributed,
and as they move from pasture to pasture,
stocking density or grazing pressure is
going to be higher, and likely the whole unit
is going to be used more evenly.
And if you get all the way
to a 50 pasture system,
they're moving every three days.
Higher density, higher grazing pressure.
Area within each pasture's more similar,
and therefore, there's more uniformity
in distribution.
So, how does this distribution affect
the different components of grazingland systems?
So, we've been this group then, since
2010 and before,
we've been looking at some critical component areas,
what's the aboveground production,
botanical composition and the response to these
different grazing strategies
in trying to increase efficiency of use.
What's the utilization of that aboveground biomass?
What's the animal performance and production
in response to this increased management intensity?
And then, what's the rates in decomposition,
and incorporation at these different nutrient pulses.
Because if cattle are only in a pasture for three days,
their affect on that system is during that three day period,
mkay.
So all of that pulse of nutrients and interactions
in that continuum of livestock.
Dung, urine, and soil,
is all being affected by those pulses, 'kay?
Rather than just a continued long stocking
during the entire 150 days on the entire area
at one time.
And then, as a result, what's the nutrient use efficiency?
So these are the group of scientists that are working
on these questions and as Richard said across many
departments and a number of disciplines within
the department Agronomy and Horticulture.
And this research we're doing
at the Barta Brothers Ranch.
And as you would all expect, a lot of graduate students,
undergraduate students, technicians involved
as well.
This research being conducted at the Barta Brothers Ranch
which is
a University of Nebraska Foundation Property,
south of Bassett
in the eastern Sandhills
and this research is being done
on sub-irrigated meadow.
So not on the typical upland range lands
that you commonly think of in the Sandhills,
but sub-irrigated meadow that's more
similar to what we would have
here in eastern Nebraska
under well watered conditions.
So, quickly, this grazing strategies that
we're comparing, then,
is something that's called mob grazing,
which is ultra-high stocking densities.
So, instead of 4-5 animals per acre,
we're at any point in time we're talking 200 plus.
And in order to get that level of stocking density
and grazing pressure, those animals are being moved
on a half day basis.
So, our graduate students, technicians then,
are moving them across
a sub-irrigated meadow
every half day with electric fence,
to get very high stocking densities
or grazing pressure at any
point in time.
And then the two conventional grazing strategies
are two four pasture systems.
One involves a four pasture
over a 60 day period, so each
of the quarter areas are being grazed
for 15 days, and then the cattle moved on.
The first one is a once over system
that the second one is a twice over system,
so the rate of movement is quicker,
and they move through the four pastures twice
during the 60-80 day grazing period.
And then we have a continuous stocked treatment
where the cattle go on to the one pasture
and they stay in it during the entire grazing season.
Meadows in the Sandhills are commonly used
as hayland, and so we do have the
traditional hay treatment along with a no harvest control.
And then also our funding sources have been
three or four USDA grants
and then University of Nebraska foundation support,
and so we also are doing much of this research
on ranches,
and this is a ranch south of Johnstown
on sub-irrigated meadow
and you can see the density of livestock,
I mean this is it.
They're at about 800 animals per acre,
and so they're moving seven or eight times per day
in order to keep enough forage available
to the cattle as they move across this meadow.
So, the purpose then with these ultra-high stocking
densities from a advocate
consultant perspective
is to attempt to speed up the rate of nutrient
cycling, we'll talk about that in a minute,
and then therefore get more organic matters,
more total carbon into the soil,
and build in the depth,
the structure, the water holding capacity,
the fertility of the soils,
therefore grow more grass in the long term, right?
And then there's other things in terms of
the evenness of fecal and urine deposition
and increase pasture productivity and increased
animal production and performance.
'Course with that many animals per unit area,
there's a lot of trampling.
Okay, so when we talk about utilization,
there's two components of utilization
from the plant perspective, right?
Plants are either with cattle, grazing them.
They're generally either consumed,
or they're trampled.
And so, very often you have high stocking densities,
a high percent of what's available
is trampled.
So there's kind of an antagonistic thing
going on here.
As you increase grazing pressure,
as you increase
the management intensity of grazing,
then is the animal gonna trample it,
or is it going to consume it?
And so it's a fine line.
Obviously most people are after high
harvest efficiency, so they want the animals
to consume it.
But at the same time they want it trampled
so that that plant material is getting into the soil
and being more rapidly decomposed.
But, we've found a lot of trampling.
So this research, like I said, those of you that have
been to Barta Brothers Ranch,
it's just on the meadow, 80 acre meadow
west of the house and lab
there at the Barta Brothers Ranch.
Dr. Belsky and I started this research
at this sight in 2010,
and then with additional support we've been able
to expand it into things like nutrient cycling.
So, to this point, just to give you a summary
of what we're finding,
we want to conduct this study
through 2018,
so have a eight year study.
But in the first four years of study
what we've found is, this more management
intensive grazing has not influenced
plant production or species composition.
So even with this higher intensity of management,
we're still getting the same level of production
in terms of plant production,
and botanical composition has not changed.
And, pretty much the same
on private ranches.
So here we have a ranch that's been
practicing mob grazing, started in 2004,
so this was about 10 years after
he initiated mob grazing,
and what this compares
is the production of the grass annually,
or of the vegetation cover
in a meadow that's mob grazed,
versus an adjacent meadow
that is simply being hayed each year.
So the mob grazing has not resulted
in any increase or decrease in terms of the production.
I see that the whole legend isn't here,
but the gray is the cool season grasses.
The brown are sedges.
Grazing tends to favor
increase in cool season grasses on these meadows.
And in terms of utilization, what percent
of what's available is actually consumed
by the grazing animal?
Again these are on three of the Sandhills ranches
that we work with, and the green bar
is the amount of standing crop
prior to grazing.
And so we have a lot of graduate students,
undergraduate students
and technicians that go out,
they clip, immediately before cattle are moved
into a strip.
They graze for a half a day, quarter day,
whatever the case may be.
Students go back in then and clip
immediately after it's been grazed.
And what they find is about 6-11%
of the standing forage is still intact
and remains after the grazing.
So this is severe grazing.
And then, anywhere from
46 up to 61% is trampled,
which means about 40-50% is actually consumed.
So a harvest efficiency of 50-60%
on many of our grazing systems,
we're talking about harvest efficiencies
of 25-30%.
So a greater percent of intake is possible
with more intensity of management,
of course that's why it's done, right,
from a economic perspective.
So then the next question was then,
by drawing the larger team together was,
what's happening in terms of nutrient cycling?
I started off talking about efficiency of use,
of forage resources on range and pasture,
and whether it can support
increase in the cow herd, right.
But, what we also want to see
is what happens to the system.
If we do move to these higher
harvest efficiency systems,
how does that influence the nutrient cycling
and nitrogen and carbon pools and so forth
in the system.
So, probly when people generally think
about grazing on grazing lands,
we look at this nutrient cycling that's spatially coupled.
So, nutrients in the soil are taken up by plants.
The cattle graze the plants, they pass on the nutrients.
The cattle are
defecating and urinating
and so that nutrient pool is returning to the soil
and so goes the cycle, right?
There's some deviations in terms of
atmosphere and so forth,
but basically we think of it that way, right?
So we've got the cattle out there grazing
and their eating and poopin' and peein'
and doin' their thing across the landscape.
And we tend to think it's all fairly even spatially
and temporally.
But actually, we're proposing then, and observation
would indicate though, that there's decoupling going on,
right?
That cattle tend to graze in places
they don't hang around or loaf around
like around water or salt locations,
and that's where they're actually doin' a lot of
defecation and urination, is in these concentrated areas.
So spatially then, that soil pool isn't necessarily
being taken up by the plant pool across
the pasture as a whole
because the nutrients are being concentrated
around favorite locations, and so we get
a nutrient loading in partial parts of the pastures.
So with the current study we're focusing
right now on dung
and how do we characterize the fate
of nutrients from dung,
and so specifically, this past two years
in 2014 and 2015, we got a team of
people looking at what is the fate of
nitrogen, carbon and phosphorus
during decomposition.
How much of it is lost via gaseous emissions.
'Course much is that is returned back
to the pasture land.
But what is being incorporated in the soil?
How does the process vary over time
through the growing season?
And then we have an entomologist, Jeff Bradshaw,
working with us from the panhandle,
and he's asking questions about how dung beetles,
dung beetles are quite common in the Sandhills,
found I think 13 different species of dung beetles
active in the meadow we're working on.
And then how does weather interact with
these questions about nutrients and dung.
Yeah, here's a few dung beetles, right?
Yeah.
It's a fascinating story, but I'll just show
that there are dung beetles.
And so, to talk through the methodology of course
would take some time and somebody with more
knowledge of it than I have, but,
of course Martha Mamot and Anna Win-Gaw-Er,
our former post-doc worked and set up most of this.
But we have a couple of graduate students then,
on the meadow they have collected, each year,
they collect a lot of crap from cattle
that are on a forage diet,
and then they,
in a experimental setup here,
they distribute that dung in blocks,
and then they make that dung pat
either open and available for dung beetle colonization,
or they cover it with screening to keep
the dung beetles out,
and then we have patches or blocks that have
no dung on them at all.
And then this laying out of the dung
is done twice, once in mid-June, once in mid-July,
and then those dung pats are followed
and data collected from them over a two month period
in both cases.
Since you're all kinda serious here,
everybody
has to have a pun or something, you know,
it's a crappy job, right?
Yeah, anyway.
Very briefly, what we found so far is that,
this is the 2014 data, is that
what's happening with nutrients, with nitrogen
and carbon in the dung pats,
and is there a difference between those
dung pats that are colonized by dung beetles
and those that are not.
Very briefly, so far, whether we're talkin' about
gas emissions, concentrations of nutrients in the soil
or concentration of nutrients in dung,
is there hasn't been differences between dung beetles,
colonized dung pats and non-colonized dung pats.
So that the amount of methane being emmitted
from those two different kinds of pats
has not differed
in terms of soil, ammonium nitrate,
there were nitrogen contents have not differed,
and in terms of concentrations of ammonium nitrogen
has not differed in the dung, okay.
Certainly different in terms of the soil concentration
of nutrients below dung pats than out in the open,
but we're not seeing a beetle effect so far.
And of course we are,
members of our group are collecting dung beetles
and using pitfall traps.
And of course, anybody know what the bait is
in these pitfall,
'cause you know you'd just have these
little holes set out in pastures
and then the dung beetles are just walkin' along
and they fall in the trap, right?
Then they're asphyxiated
in basically this is antifreeze,
but do you know what attracts them to that trap?
Chimp poop.
So our entomologist from Scottsbluff,
so he goes to the Scottsbluff Zoo
and gets a order of chimpanzee poop,
because it really gets the dung beetles going,
so it's a way to
(crowd laughing)
collect dung beetles
on these different treatments to see
where they're the most active.
Interestingly though, we thought perhaps
we had hypothesized we'd see the greatest
density of dung beetles on the mob grazed areas
because there's that spatially and temporally
a consistent supply of dung,
but we haven't seen a difference in diversity
as far as the diversity index
with a difference between mob grazed
and the conventionally grazed pastures, okay.
So the beetles aren't exactly responding
as we thought they might be.
So, with this baseline information relative to
dung decomposition, nutrient release into the soil,
nutrient concentration in the soil,
we then want to take that out to the pasture
level and so we want to see then
how do grazing strategies impact
the temporal and spatial
distribution of the renewed nutrient pools.
So, in a
high density, high stocking density area
within a management unit,
there should be more even distribution of dung piles,
dung pats, and urine spots.
Because the animals are more evenly distributed,
whereas in a continuously stocked pasture,
at the other extreme, the cattle tend to
hang out in their favorite places,
and then the dung pats, urine spots
are located around those areas.
So, since we know then, we're learning
more of the dynamics of nutrient cycling
with static dung pats.
What happens then, out in a pasture?
How does this impact nutrient cycling
if we have those dung pats more evenly distributed,
versus them congregated, concentrated in
favored areas of the cattle.
And so yes, we're using UADs too, and Richard Ferguson
as you saw is part of this study,
and so started late last summer
in using UADs or drones to map out the location
of dung pats and urine spots
on these different types of pastures.
And so then our goal is to quantify
potential at the pasture level
of soil nitrogen mineralization,
carbon storage, phosphorus availability
and so forth is our goal there,
here in the next year.
And eventually then, Hy-Shun-Es is the modeler on the team,
then there will be a modeling exercises
to develop the explanations, the directions,
the models for nutrient cycling on these pastures
that are managed with different intensities.
So, in the end, can we use our pastures
more efficiently to not only
to increase the efficient use of the forage resource,
but how does that affect long term production
of those sights, how does it affect species composition,
what's happening above and below ground relative
to nutrient availability and patterns
of availability of the nutrients
and then can we model it?
So that's where we are.
Richard.
(applause)