Good day.
My name is Keith Johnson.
I'm a professor of agronomy and the Forage Extension Specialist at Purdue University.
And it is my great pleasure to provide all of you watching this webcast today, information
about SEN-USA Bioenergy.
This is an Iowa State University-based USDA National Institute of Food and Agriculture
Sponsored Research Project that has investigated the creation of mid-western sustainable biofuels
and bioproduct systems.
A website, SEN-USA.iowaestate.edu, shares the work of this project with everyone interested
in producing advanced transportation fuels and bioproducts developed from perennial grasses
grown on land unsuitable for or marginal for row crop production.
Our guests today are Dr. Rob Mitchell, who is a research agronomist with the United States
Department of Agriculture, Agriculture Research Service, is within the Wheat, Sorghum and Forage
Research Unit at the University of Nebraska-Lincoln.
Our second guest is Dr. Michael Kassler.
He is a research plant geneticist.
He's with the USDA Agricultural Research Service and University of Wisconsin out of
Madison, Wisconsin.
An opening question for both of you gentlemen is, why are perennial grasses a good candidate
as a biofuel feedstock and which ones are the strongest candidates?
Rob, do you want to start us off with that?
Yeah.
Thanks, Keith.
Well, as we're looking at some of these potential bioenergy feedstocks, the perennial grasses
make a lot of sense in that they are perennials.
They can be planted once and harvested for a number of years.
We have studies in the ground now that have been, we're now in our 20th harvest year on
those particular trials, so they can be planted once and be grown really in perpetuity if
they're managed well.
Secondly, they're highly productive on margely productive crop land.
And that's one of the areas that we've been focusing these perennial grasses on is that
margely productive crop ground that might be sloping, might be that CRP-type grassland
area that people picture.
They might be wet.
They might have some issues with size or difficult to get into with some of our currently large
modern machinery.
And so they fit well in those margely productive sites because they can do pretty well with
a lower quality soil and can provide some opportunities where row crops might not be
the best option.
You know, within my career, not too long ago, it was thought it took several years for these
perennial grasses to get established and to get the full yield potential.
And we now know that's not true if best management practices are followed when planning for and
establishing these grasses.
What needs to be considered to improve the success rate of establishing one of these
grasses that we've focused on the most, switchgrass?
Yeah, that's a really good point, Keith.
You know, over the past decade or two, we've really made some improvements in several areas.
One is in the equipment.
We're actually, we've got better equipment to plant some of these perennial grasses.
We've also got better herbicide options, and those two things really have given us good
opportunities for success when planting these perennial warm season grasses.
So as we look at those issues, really some of the things that show up for us are getting
the seed in the ground at the right time and at the right depth and then managing weeds
in a timely manner.
So some of the questions that we get pretty regularly are, you know, when should I plant
switchgrass?
So from a timing perspective for us, we really focus on about two to three weeks before or
after the recommended corn planting date in an area, and that has held true very well
throughout the world, really, where we've recommended switchgrass to be planted.
So if you've got a good solid recommended corn planting date in an area, two or three
weeks before to two or three weeks after really gives these perennial grasses, switchgrass
included, a good opportunity for success in getting established.
Now that's wonderful, that's really wonderful because it does give them a great length of
time.
I mean, we're talking about four to six weeks, which is a really wide, wide window.
The other things are, we get questions about, how should I prepare the seed bed?
Well, if you've got an opportunity to plant a head, and can the year before you're planning
to plant the perennial grass, put that area in rounder pretty soybeans, beans make a great
seed bed for a no-till seeding switchgrass and these other perennial grasses.
So if you can plant soybeans the year before, great wheat control opportunities, very nice
seed bed to no-till seed into.
If you have to prepare the seed bed, if you've got a lot of trash, like in a fallen corn
or some sorghum or something like that, if you kind of get it in your mind to prepare
the seed bed like you would for an alfalfa stand, that's a pretty good way to think about
it.
The switchgrass is pretty small seeded, you've got probably 250 to 400,000 seeds per pound
in the switchgrass, so it's really a small seed.
If you go to the books, most of the books will probably tell you 389,000 seeds per pound
per switchgrass.
I'd be happy to see that in a seed lot, but that's pretty close, there's a lot of seeds
at the big point, and it's a small seed.
So planting the seed at the right time and at the right depth.
With our modern planters, like our no-till drills we have available to us, most of those
can be equipped with depth bands, and we can put a depth band on a no-till drill and really
control the depth of that seed placement, and that's really critical for us.
We really want that seed to be planted only about a quarter to a half an inch deep.
If you get it much deeper than that, that's really a big issue for us in getting that
emerging seedling up above the ground, giving an opportunity to succeed.
The other one is weed control, and so for us, especially throughout much of the central
plains and Midwest, grassy weeds end up being one of our biggest problems for establishment
success.
We now have some pretty good herbicide options for controlling the grassy weeds, and right
now, FACET-L is one that's labeled in a lot of states, and so we can apply a pre-emergent
application of FACET-L in the spring, do a really good job of controlling those grassy
weeds, and then usually for most of our areas, by around the 4th of July, we'll start to
see the broadleaf weed problems show up.
At that point, really is a good time for us in general to think about broadleaf weed control.
For this area, what we end up doing is a pre-emergent application of FACET-L for controlling the
grassy weeds, plant the seed in the ground at the right depth and at the right time,
and then pray for rain, and then come back sometime around the 4th of July and apply a
broadleaf weed control with 2,4-D.
Rich grass and most of these native perennial warm season grasses tolerate 2,4-D very, very
well, and you can use some pretty high rates to burn back the broadleaf weed issues.
But as you mentioned earlier, our goal now in establishing these warm season grasses is
not just to get seedlings to survive in that first year.
Really our goal, and it's a very realistic goal for us here, is to put that seed in the
ground and by the end of that first growing season have a harvestable yield, so we can
actually be harvesting the plant material from the field in that first year of planting.
I've done this a lot of places, done this at my own place, and I've even after frost
raised native warm season grass plantings the year of planting.
So if you do things right at the right time, really the opportunity for success is very,
very high.
And then by the end of that next growing season, we're pretty close to full production.
Well, these are great tips, then if we look at the greatest concerns, and what are the
things that you've seen that have caused the greatest failures?
Yeah, really for us, the big deals are when I go look at stands, it's usually they planted
it too late, or they planted the seeds too deep, or they had poor weed control, especially
on the grassy weeds, and it's usually one of those three things that leads to a poor
stand success in that planting year, and quite often it's that planting too late.
It's hard for me really to encourage people to plant these warm season grasses too early.
In fact, some areas they recommend frost seeding.
So frost seeding after in November, we don't do that here because we have really good success
in our area by planting in the spring, but if you get that seed in the ground early,
I like to kind of target that end of April for us.
That just is a really nice time for we get really reliable rains, and that's really critical
for us as that soil temperature is warming up, that we get rains to keep the soil wet,
keep those seedlings alive while they're in that really fragile stage.
Yeah, very good.
You know, one of the things that we need to think about then, and moving to Dr. Kassler
is the call of our choice is an important part of the management as well.
Dr. Kassler, you've been breeding switchgrass and big blue stem for use in a future biomass
to energy industry, and what has been the major goal of your program?
Okay, thanks, Keith.
Actually that's a very simple question to answer.
We really have one main goal, and that's to get to 10 tons per acre.
And the reason I use that number, and the reason I've chosen that goal is because all
the economic and life cycle analysis modeling studies have shown that our yields are really
not quite high enough to be economically sustainable yet.
They're right on the margin.
A really, really good producer who has some experience can produce economic yields of
switchgrass for biomass conversion right now, but we want to get that to a point where it's
higher where more people can feel comfortable with having economically sustainable yields.
So that's our main goal, to increase yield and to get to 10 tons per acre by about the
year 2025 or 2030, something like that.
Very good.
You know, one of the things I've enjoyed about being part of the SEND USA project is looking
at the diversity of switchgrass.
In my opinion, it's just quite amazing, and I enjoy going out to the field every time
I do to look at this great diversity.
So you've been using this genetic diversity attributes to achieve your goals of that 10
ton production.
So what attributes do these different types have?
Yeah, Keith, I share your enthusiasm about that.
I've been doing this for 20 years, and I'm still as enthusiastic, maybe even more so
than when I started on this.
It's been a lot of fun.
To boil it down, very simply, there are two types of switchgrass.
There's what we call the upland type and what we call the lowland type.
In this part of the country, the north-central United States, if you go out to native prairies
and Savannah ecosystems where you see switchgrass growing in places where it's been for thousands
of years, that's all what we call the upland ecotype.
It's very short, it's very early flowering, it's a good forage type, and we've been using
it as a forage.
Rob and his colleagues in the Great Plains have been using it as a forage for a long,
long time, 60, 70 years since they started breeding forage varieties in the Great Plains.
But it's not a good biomass type because it flowers in early August and in this part
of the country, and once it flowers, it stops accumulating biomass.
When you think about that, there's actually about five or six weeks left in the growing
season where it's not accumulating biomass.
The temperatures are still warm enough that it could still be growing.
What we've been focusing on is this thing called the lowland type, and if you look for
the lowland types and look at what they are, their characteristics and where you find them,
you've got a little bit of an issue, which really for me is just a challenge as a light
breeder, because all the lowland types come from the Southern United States and they're
very tall, they're very, very late flowering.
So if you bring them up here and you can get them to survive, they flower about four to
six weeks later than the upland type, which means they're actually utilizing the entire
growing season.
Now, Rob and his colleagues in Nebraska, they can grow a few of the lowland types in Nebraska.
They're far enough south and their climate is warm enough that they're just at that point
where they can grow some of the northern adapted lowland types from Southern Nebraska, Kansas,
Oklahoma.
You get up into our part of the country, Minnesota, Iowa, Wisconsin, Illinois, and farther east,
which is a big part of the San USA region, the North Central region, and we can't grow
the lowland types.
So what we've been focusing on, Keith, is we've been bringing these lowland populations
into the Northern United States, into Wisconsin, where our breeding program is located.
We've been growing tens of thousands of plants of many, many accessions, because we don't
know the right accessions, we don't know which ones are going to be the most winter hardy.
We grow these plants, and we let nature take its course, and what nature does is it kills
most of them, and that's exactly what we want.
We dig up the survivors, and we then intercross those survivors, and of course that's not
the easiest thing to do, because they'll flower here in Wisconsin, but they won't produce
seed here in Wisconsin.
So that's one of the things where San USA has been very, very helpful to us, because our
San USA collaborator in Illinois has been very willing to work with us.
So every spring, what we do is we dig up all of our survivors, we load them up in a truck,
we drive down to Illinois, we plant them in a field at the University of Illinois, and
then we go back down in September, October, and we harvest the seed from those, and we
go through generations, several generations like that, then to be able to increase the
rare hardiness that we blow with types.
So essentially what we're doing, Keith, is we're developing northern adapted late flowering
lowland types by just combining that late flowering trait with a winter hardiness trait
that we need to give higher biomass yields.
Now, very, very good.
So it's a process, isn't it?
What is the amount of time and effort that it takes to do all of this?
You talked about taking it from Wisconsin down to Illinois to be able to develop the
seed and so forth.
This doesn't just happen in a matter of a year, does it?
No, no.
So we can go through a generation of selection in about a three-year period.
We have to start with seedlings, we have to start with seeds that we've collected in the
Southern United States, we generate seedlings, we plant those in the field here in Wisconsin.
If all goes well and the first winter is a really harsh winter, and it kills a lot of
our plants, then we can make selections right away.
But if it's a mild winter, then we may have to wait another year until we get that selection
pressure and that harsh winter to kill off most of our plants.
And so usually they'll go through two winters, we'll dig up the survivors, we'll drive down
to Illinois and then we produce the seed and that's a three-year period.
Based on the data that we have so far, we think it takes about three generations to
get enough concentration of the genes that control winter hardiness to be able to have
a new variety, at least a new candidate variety that has the winter hardiness that we can
basically say, yes, we really feel confident that this is a Northern type.
So right there, that's nine years, nine years from the time that we collected the seed in
say, Mississippi or Alabama or Texas, three generations of selection.
And then we've got a bag of seed that's been through three generations of selection, we
feel pretty confident, then we still have one more challenge, we've got to do some testing
at many locations.
And that's where CEN-USA has really been valuable to us because one of the hallmarks of the
CEN-USA project is we've had this multi-location uniform trialing system with 13 locations
where we've been able to test a lot of our candidate varieties.
Well, let's take a look then at some of the success that you've had, Mike.
You know, you've got a graphic there that looks at over the course of some time and
differences in your development, so take us through the progression of yield improvement.
So the only data that I have to share with you right now, Keith, is the slide that you're
referring to, which is a population that we call WSK4 Cycle 2.
It's been through two generations of selection, and you can see we're comparing it in Wisconsin
to the Northern upland type, so it's what we call a Northern lowland type.
And you can see the average increase in yield is about 72%.
And that population actually seems to have enough winter hardiness that it seems to survive
fairly well for us over a two or three year period.
So our expectation is it'll survive longer than two or three years because we did have
some pretty harsh winters there.
So that's the kind of gain that we can expect is around that 70% increase as a result of
that.
Well, that's just really phenomenal.
I mean, that's just great.
But then thinking about this, have you learned anything in all of this research that you've
done, Dr. Kazler, are there any pitfalls or potential problems associated with these developments?
Yeah, unfortunately, Keith, we have.
A couple of things that we didn't think about when we started this whole process, but they
have come to mind and they've come to the fore.
And there's a lot of discussion right now about nitrogen requirements.
There's a large group of people that would really like to see us wean ourselves away
from nitrogen fertilization of these bioenergy grasses.
Nitrogen is, correct me if I'm wrong, Rob, but I think it's the single largest expense
in producing biomass from a perennial grass.
And we'd like to see if we can figure out how to reduce that or eliminate that.
But the problem is, if we increase yield by 72%, we're increasing the nitrogen demand
by almost 72% as well.
Because what happens is you end up drawing more nitrogen out of the crop in order to
get that increased biomass.
So we have a long-term goal of actually trying to figure out how to develop switchgrass varieties
that have a lower nitrogen demand.
We know we can do that, but it's going to be a long-term goal.
It's not going to happen in the next five to seven or 10 years.
It's probably going to take about 20 years to develop new varieties that have a significantly
lower nitrogen demand.
So in the meantime, that's one potential disadvantage is we've increased the nitrogen demand.
The other is something kind of interesting.
My ag engineering colleagues give me a hard time.
They say that it's going to cost more energy or require more energy to harvest these grasses,
something I never really thought about.
We don't have any data on that yet, but I think they're probably right.
There's a lot more biomass out there than there used to be.
Yeah, very interesting.
And just the continued need to follow up with research from things we've learned, from
research that we're doing currently, is just really critical to make this the best that
it can possibly be.
So I appreciate you mentioning those potential issues.
I'd like to return to a question to Dr. Mitchell then.
We saw some data that Dr. Kassler shared.
You are from a drier weather environment than Dr. Kassler in Wisconsin being from Nebraska.
What types of yield have you achieved in the Great Plains?
And then when does this harvest actually occur?
Yeah, that's a good question, Keith.
With the Senua SA project, one of the things that we started doing is it gave us the opportunity
to plant some of this material at the field scale.
And so that's really been a benefit to us, is to have enough material that we could plant
at the field scale and harvest it with typical pay harvesting equipment.
And kind of going back to some of what Mike said, one of the issues that I didn't anticipate
is the amount of material that we're leaving in the field.
We're seeing this material kind of being forced through our typical hay handling equipment.
And back to some of the comments that the ag engineers make is that it really is a lot
of material to handle at one time.
And so that causes us a lot of leaf shatter and a lot of loss.
So we can actually go back through those windrows and sort out how much we've left in the field
just because it's a lot of stuff to deal with.
So that's an issue that kind of gets back to that question you asked Mike.
But as we kind of think about where we've been over the past 80 years or so working
on these perennial grasses and where we are now, there's no something for nothing, as
Mike was indicating.
We've got some long term studies where we've got zero nitrogen, 55 pounds of nitrogen
per acre and then 110 pounds of nitrogen per acre.
And really the zero end plots, they are very poorly productive.
So there's been a push that to say, boy, these natives, they don't need nitrogen, don't put
exogenous nitrogen on them, don't fertilize them, just let them make it on their own.
Well, those yield very poorly.
And some of the data, we've got, you're in about a one and a half tons per acre over
a 10 year yield average.
And we now have about 20 years of yield data on that particular study that I'm referring
to.
But as you start to apply a little more nitrogen, you see really a nice increase in yield of
those particular switchgrass plants.
It does respond pretty nicely to nitrogen.
We have historically probably over fertilized kind of the yield rates we've been getting
from a yield perspective.
But for us in the great plains here, in that five to six ton range, we probably really
need to be putting on at least 50 pounds of nitrogen per acre per year.
And that's kind of what our research results demonstrate.
The other side of that is you ask the question about when should we harvest it?
And Mike would probably smile just like me because it depends.
What do you want to use the material for?
If you want to use the material for hay, for cattle, I would suggest harvested the first
of August.
We can do a, in this area, first of August is about our peak amthesis period.
And so if we're harvesting those upland eco types like Mike referred to, cultivars like
Shawnee, harvesting around the first of August for us kind of maximizes that yield potential
but also kind of optimizes with that the quality, the forage quality.
So we can provide a quality hay with a reasonable yield that is a good forage for livestock.
Now if you're focusing on bioenergy, one of the things that we've found with harvesting
for bioenergy is we're much better served to harvest after killing frost.
So by delaying harvest until after frost, it gives us a couple of advantages.
One, it gives us a really nice advantage in maintaining stands.
We can maintain quality stands with a lower nitrogen rate because we don't have some of
the invasion problems from the cool season grasses that we see throughout a lot of our
area.
Smooth Brom and Kentucky Bluegrass invade these pretty readily.
And so if we harvest them after frost, we don't see so much of that invasion issue.
But it also does a really nice job of giving us an opportunity to recycle nitrogen back
into the system.
As Mike talked about, nitrogen is a huge input into the production of these perennial grasses.
And anything we can do that reduces that nitrogen fertilizer input is a great thing for us.
So by delaying harvest until after frost, we recycle a lot of nitrogen back into the
below ground portion of the plant, which gives us now an opportunity to reuse that the next
growing season.
Well, you know, one of the observations I've had in the work here in Indiana is that when
you do exceed, you know, that 60 pound of nitrogen per acre kind of rate, one major
windstorm with high nitrogen can lodge that crop.
And that really can lead to some major harvesting issues in a lot of lost crop in the field.
It is a pain to harvest lost material.
I agree.
So let's move on and talk a little bit about, you have some interesting things to share
regarding the post-establishment investment that a producer might have when producing
switchgrass.
I had trouble hearing that, Keith.
I'm sorry.
Okay.
So you have some interesting data that's looking at the post-establishment investment
that a producer will have when producing switchgrass.
So what are some of the current production costs?
Right.
As we think about what it costs for us to grow switchgrass, since it is a perennial,
one of the things that we can do is we can amortize those established from a cost over
a number of years.
And for us, 10 years is very realistic for us to have a stand in production.
One of the trials I had mentioned earlier was planted in 1998, and it's still going
strong.
We've got some other studies that were planted in 2006 that we've harvested for biomass and
now are grazing for kind of a dual purpose process.
So if you can keep these stands in production very easily for 10 years with some good management.
So as we look at the establishment costs, one of the things we do is we amortize that
out over 10 years, because that really does a nice job of spreading out that cost of establishment.
As Mike mentioned earlier, when you look at nitrogen fertilizer, it does require nitrogen.
And typically we can look at, for us, about $30 per acre is what we end up investing in
nitrogen.
And then the other downside is Mike was talking about with yield.
As yield goes up, your cost of harvest doesn't go up, but your cost of baling goes up because
you're putting up more bales.
So that's another interesting issue that a lot of people don't think about is the more
you produce, the more bales you've got to make and the more that costs.
So from a cost of production perspective, really, we're looking at kind of at a target
yield in that five to six ton range, which is really very doable for us in eastern Nebraska
growing this stuff dry land.
And our production costs, again, depending on the land costs, and that's really the
big driver for us is how cheap can you rent land.
But if we look at a reasonable cost of land in our area of about $150 per acre cash rental
rate, again, we're focusing on more personally productive crop land, so it's a little cheaper
rental rate.
We can really do a pretty good job of growing switchgrass in that $65 to $70 per ton range,
which gives a producer an opportunity then to make some revenue if we hit some of those
targets of $85 to $100 a ton, what we're looking at for biomass energy, a sale price.
Do you have any projections on the amount of production necessary for a fuel production
facility to operate?
Well if you look kind of basically at a kind of the scale that's required for many of these
ethanol facilities to be very productive and to be profitable, the target has kind of historically
been about 50 million gallons per year.
And so for us to provide enough feedstock to run a 50 million gallon cellulosic ethanol
plant 365 days a year, that takes a lot of material.
So if we do some back calculating and say that a ton of switchgrass, for example, we
can produce about 80 gallons of ethanol per ton.
If you do the math on the 50 million gallon plant, that 80 gallons per ton, that tells
you you're going to need about 625,000 tons of material to meet that feedstock demand.
Well that's a whole bunch of material.
So not only is it a whole bunch of material, it takes quite a bit of land.
And as Mike talked about earlier, yield is the key.
If we look at some of those real low yielding cultivars and low yielding management practices,
if you're only in that one to two tons breaker, you're looking at a fourth to half of the
land area in a 25 mile radius around a cellulosic ethanol plant, having to be in a perennial
grass to provide enough feedstock.
And that just isn't, that's not even really, we don't even think along those lines.
But when we start getting into those five, six, seven, eight ton yield ranges, now it
really only takes maybe about between seven and 10% of the land to be in production around
that cellulosic ethanol facility to produce enough feedstock to run that plant all year
around.
So if you kind of look at that on a daily basis, it kind of shows us how staggering really
this amount of material required is.
Because again if you're looking at 625,000 tons of feedstock needed per year to run
one of these facilities, that ends up being about 52,000 tons of material that's needed
per month.
You do the math on that and that's about 1,700 tons per day, and if you're going five
tons of biomass per acre, that takes about 340 acres of switchgrass a day to run that
facility, which is, that's a fair amount of land.
And then to kind of put that one more step down the line, that's unloading 81 trucks
a day.
And so that's a lot of trucks coming into a facility, providing biomass for a biomass
bioenergy facility to kind of put that on the football fan being from Nebraska.
But if you put that kind of in the football perspective, to store that much material just
for a month, that basically covers a football field to a depth of about 130 feet if you
make some assumptions of 15 pounds per cubic feet and 133 cubic feet per ton.
So that's a big pile of material.
So to provide that much biomass is really a big chore.
So it is a, it's not an easy thing.
Finding that amount of land is certainly an interesting thing and we don't have time
to go into specifics, but I thought conversation and things that I've seen from you about
the corners of those center pivots in the plains as an opportunity there to get an amount
of acreage that could be an opportunity because of course they're not under irrigation and
then from the standpoint of marginality for row crops is certainly a worthy consideration.
Yes.
Well, let's then kind of bring Mike back and Rob and I think we're at a point to finish
up this webcast.
Do you have any closing comments, gentlemen?
No, I think that about sums it up.
I can't think of anything else.
Okay.
Rob?
No, I think we've pretty well covered it, Keith.
Thanks again for the opportunity to share some of our information with you.
Well, it's been a real pleasure for me to spend this time with two individuals I have
great respect for and you've been a great part of the CENUSA project and thank you again
very, very much for sharing your great expertise.
Thank you.
Yeah, you're welcome.
Thank you, Keith.
