cc
for coming. >>My name is Tim Donahue.all
And again I'd like to thank you for coming to a special seminar
that's sponsored by the Great Lakes Bioenergy Research Center.
For those of you who don't know what the Great Lakes Bioenergy
Research Center is, it's a new
housed at the UW-Madison, but functioning as a virtual
center across the country to help develop and rollout
technologies for the conversion of cellulosic biomass
into fuels. One critical part of that
center's activity is the topic
in particular, in addition to work going on in the center
on the improvement of plants, and microbes
and chemical activities to make it easier to convert
plant biomass into fuels, there are significant activities
in the center worrying about
observations from the lab bench the out into the field.hose
And that's under the broad
activities. bruSo there's been a lotity
of legitimate discussion in the free press lately about how
biofuel activities can and will be sustainable in the future.
And so it is very timely
Phil Robinson, who's the leader of the sustainability program
in the GLBRC agreed to come over
and give a talk on those aspects and visit with people at Madison
As I said, Phil is the leader of those activities.
And he's the perfect person in our mind to do that.
He's a professor of Ecosystem Science in the Department of
Crop and Soil Science at
And he's been there since 1981. Since 1998, he's directed the
Long-term Ecological Research Program in Agricultural Ecology
at the Kellogg Biological Station, the experiment station
in the state of Michigan. So he brings to the center
and to the table in this
and internationally-known aresearch program, in thinkingve
about and dealing with issues related to sustainability.
So with that, I will shut up
I thank him for coming today. ( applause )e Phil.
Well thanks, Tim, and thanks everyone for showing up
this morning. It's a pleasure to be here.
And it always amazes me that
that wasn't on most of our I'll be talking about a topic
ago. radar screens only two years
about in many respects, partly And it's a fun topic to talk
But more importantly, because it because it's controversial.
about agricultural ecosystems iin a way that helps to informow
the sustainability of these systems, and perhaps the birth
of a new agricultural industry
and across the world. Well, let me start
by explaining a little bit
morning this particular way. about why I phrased my talk this
the "Biogeochemical Challenge." There are, of course,
a lot of different aspects
biofuel cropping systems to the sustainability of
We have to think about economic and cropsustainability, general.
profitability of these systems. If they're not profitable,
of course, they're not
We have to think about the going to be sustained.
of which biogeochemistry environmental sustainability
We have to think about is a part.
of these systems, the potential for these systems to contribute
to rural development and the
And, of course, we have to sustenance of rural communities.
A part of this has been in the press a lot in the.
past few weeks and causing
sustainability of biofuels some people to doubt the overall
And I'll talk about that in general, for good reason.
We're considering all aspects of sustainability in the GLBRC,
but I want to focus on
of my talk today. biogeocheFirst, becausemain part
if we can't get this part right,
a lot of their attraction. then biofuels lose
apart from the issues of energy security, we're in this business
for an environmental standpoint,
potential for helping lto stabilize climate.ir
So climate stabilization
of the atmosphere wis a biogeochemical issue.
And second, while the biochemistry is not complex,
there are aspects of it that are quite simple, in fact,
there are a lot of pieces that
really to design sustainable have to be understood if we're
of these systems in the future. sysSo I think it's important out
for all of us to understand at least most of those pieces.
So as you'll see, we're not talking simply about carbon
balance, we're talking about
perhaps some other co-benefits, some biochemical co-benefits
of these systems as well, on
and the potential for cellulosic nitrogen cycling, for example,
some of the nitrate issues and systems to ameliorate
that we now face with agriculture as it's done today.s
And I'll talk in detail about the biogeochemical needs then
in relation to our ongoing
And then I'll describe, I'll research effort.
actually more than just a few minutes, to describe the
overall sustainability research that we anticipate will be
a major part of the GLBRC in the years to come.
It's a major part now, but
is just getting started. the GLBRC as many of you know,
still in its very nascent part. From the outset, the promise of
biofuels is a win-win situation for a lot of reasons.
It's a win-win situation from the standpoint of farmers
in many respects. It's a win-win situation from
the standpoint of the environment in many respects.
It's a win win situation from the standpoint of some key
social issues, as well, for society, I would argue.
But that really is the case only if it's done right.
There are a lot of opportunities
We need to be aware of those for doing it wrong.
And that's one of the reasons that we're extremely pleased
to be part of the GLBRC from
some of these problems the outset to try to anticipate
a major part of the biofuel economy in the years to come.
So it might be helpful to start at the top
and close to first principles,
the controversial nature simply because given
colleagues on both sides of what we're about, and I have
that have arisen, in some cases yelling at each other in print.
It could be useful to think for a moment about what we're
trying to achieve with this.
what we're trying to do is And at one level,
into the economy to a trickle. to reduce the flow of petroleum
to read the pieces on this, YI'm not so much interested
in that, as you're seeing the size of the arrows.
This is a description, a DoE
the most recent year available, or petroleum flow for the most
recent year available, 2006.
of 15 million barrels a day coming into the U.S. economy.
Around 10 million barrels that are coming in as imports,
and the remainder as produced here.
And I'm not going to take you through all of these pieces,
the important part is this bit down here,
these 14 million barrels
translates to about nine million of transportation fuel, which
And it's that that we're trying to reduce to a trickle
from a societal standpoint. We want to reduce this fat arrow
here, which is the biggest
to something akin petrto what electric poweromy
is currently using. So the EPA released a couple
of months ago an analysis,
of the transportation sector a wedge analysis
And a wedge analysis is simply petroleum use.
wedges for stabilizing climate a way of taking Steve and Bob's
2006, in this case. What technologies would need
to be brought to bear to keep CO2 concentrations
in the atmosphere at levels that are 2006 levels.
And this is specifically
of the CO2 burden for tin the atmosphere.part
And the EPA divided this
nine different wedges. stabilization triangle into
the issue of asking Iwhat different technologiesng
can contribute, how much to solving
the stabilization problem.
identified, that would be Apotentially available,y
and needed to stabilize 2050
at 2006 levels CO2 levels in the atmosphere
And the values here are the size are these listed here.
And so, gasoline hybrids of the wedges that are needed.
somewhere on the order are expected to contribute
to the solution, of .8 to 1.0 wedges
Plug-in hybrids, 1 to 2. which requires nine wedges.
the various technologies that are thought to be necessary
to bring us to this point.
in this. The biofuels plays a role
different scenarios that EPA And a role in all other
And the thinking is that presented.
on the order of 1.3 to 2.7, bidepending on the scenariosre
that are presented. Wedges to contribute to a total
of six to 13 wedges, which
the transport sector's would be enough to stabilize
stabilization at 2006 levels. And this 1.3 to 2.7 translates
to about 40-80 billion gallons
So that's one analysis of the target we're heading for, is
that amount of quantity of fuel.
I wouldn't necessarily believe Now this taken by itself,
without some additional support. the EPA's analysis
did a similar sort of analysis, a year or so ago, and came to
basically the same conclusion.
divide the total transportation, That is, by 2050, if we can
in terms of today's million expectebarrels of oil.n needs
So something on the order of 17 million barrels of oil
per day, projected to be needed by 2050, some portion of that,
a large portion of that,
with efficiency and smart growth we ought to be able to achieve
But some portion of it policies and behaviors.
we're still going to be reliant on liquid transportation fuel.
That liquid transportation fuel could be biofuel.
Some part is still going to be
There's no issue there. But they came to a similar
number, somewhere on the
of ethanol that's needed. oSo there's a considerables
legislative momentum starting to set the trajectory
for this as well, as I'm sure most of us are aware.
In December, the U.S. passed
of 2007, which aims to produce the U.S. Energy Policy Act
in 2022, which means 22% of transportation fuel mix
that's projected to be available 36 billion gallons of ethanol
which is not very far from now. And 21 billion gallons of that
is expected to be, by target, cellulosic ethanol.
And 15 billion gallons
The EU is close behind. The EU recently set a target
of 20% renewable energy by 2020.
of that target, is targeted Ato be transport fuel.lf
So there's also a big push in Europe for the quick development
of these fuels. We're pretty close to
the capacity that was already identified by the Energy
Security Act, which currently,
of about 13.5 billion gallons. we have a capacity in the U.S.
about 80 billion gallons So we call that, we're talking
as a total need. or 60 billion gallons
targeted for 2022, And if 15 billion gallons
for grain alcohol. we're just about there
say maxed out, but we're So we're effectively, I won't
more rapidly than many of us very rapidly getting there,
But in any case, just to would like.
versus where we're aiming to get put in perspective where we are
society, we're well on our way as a society, as the legislative
So the next question is thow much biomass is needed
to satisfy this quantity
If we take as a target of ethanol.
some 60 billion gallons, a midpoint of the EPA range,
grain biomass using today's wtechnology that translates
to about 2.6 gallons of ethanol per bushel of corn.
We're look at about somewhere around the order
of 23 billion bushels of corn needed to satisfy that demand.
And you can compare that
that were produced in 2007. to 1If you look at futurecorn
technology, this is a fairly
In the near future, it's likely to produce only an increase
of around 10%, up to
mainly due to higher starch varieties coming into the
processing stream and grain cellulose conversion.
We're likely to see a need
of 20 times ten to the ninth for somewhere on the order
over the capacity of the U.S. bucorn market to satisfy.ell
So, clearly there are limits
ethanol. to what we can do with grain
cellulose ethanol. And we have to turn to
how much biomass do you need And we then have to ask, well,
And again, we can look at today's technology where
pilot plants are producing
ethanol per kilogram of biomass. on the order of .3 liters of
to make. And it's an easy calculation
kilograms of biomass Figure out, well, how many
that much ethanol. does one need to produce
around 776 million metric tons And it comes out to somewhere
Well that's a big number. What do you do with that number?
How do you compare that number
Well, one way to think about to what is available?
the corn stover that is produced that is to think about all of
number to calculate, because in the U.S., which is an easy
stover produced in above ground theresidue in a corn fields of
as is produced in grain.
the overall yields of corn, Aactually this is an analysis
that covered the period,
196 million metric tons of corn stover were produced
and Graham, and others, who produced this analysis
also suggested that about half
could be removed of that, about 110 metric tons,
That is, if these corn fields were grown under a no-till
situation, so that some proportion of the litter was
left in place, not harvested, in order to protect against
erosion, and in order to provide
for carbon sequestration, then enough biomass
more on the order of we're probably thinking about
metric tons that could be 110sustainably removed.xth
We could also think about the amount of biomass that's
available from industrial waste,
as well as from the wood products industry.,
Material that is readily
in an industrial setting harvested, simply because it's
in effect already. in point source
to pull together And so it would be fairly easy
So we can think about needing 776 million metric tons of
biomass for today's technology. And it's likely that we will get
some improvement in that
research in large part, so that we might be looking at something
on the order of .43-liters
which would bring us to the need of biomass yield in the future,
So the stover and the wood waste for 530 metric tons of biomass.
Those are readily available now in today's technology.
without harming the productivity
I'm not suggesting that if of the current cropping systems.
corn system that would be a way to satisfy part of that need,
but just with existing
this is a kind of biomass techthat we could divert nowes,
to a cellulosic biomass stream. So taking these numbers then,
you can ask, well how much land is necessary to satisfy this.
And if we subtract off the
come up with 560 million low hanging fruit, then we can
technology, 314 for tomorrow's technology.
And we can think about how many millions of hectors are needed
to bring into production
But if we take switch grass at today's yields, and these are
realistic field-based yields, not experiment station yields,
somewhere around 7.5 metric tons
calculate that we need somewhere per hector, then we can easily
of land, on which to grow switch grass in order to satisfy
100% of this ethanol need.
might be able to increase that yield, we might be able
to get away with only 42 million hectors.
If we were to use human grasslands, native prairie
perhaps, then we would need,
than a switch grass system, we would need somewhere on the
order of 112 with today's technology, and somewhere
on the order of half of that
So the basic answer here is we need somewhere between 40
and 100 million hectors of land on which to put this technology.
Well how much is that?
consider that we only have It's a lot, because if you
currently cropped in the U.S., 180 million hectors of land
a large portion of that to cellulosic biofuel production
without having severe impact
We also have, however, on food security.
Some of those are arid range a large number of grasslands.
of it is grasslands that are lands, but a fair proportion
because they're not currently claused as production.ds,
They're marginal land, perhaps
abandoned and is now in folandscapes as successionaln
systems.
15 million hectors of CRP land, which could be harvested if
the rules were changed
And so we have this need and added to the stream.
40-100 million hectors of land. forIt could be satisfied ifof
we think about land that, especially land that is not
currently used for food.
I think, of a cellulosic And that's one of the promises,
the current grain-based economy, bioenergy economy, as opposed to
all know from recent spikes in grain prices certainly,
has a big impact
So there's another aspect of this, too, and that is that
we also have a fair proportion
especially in the Great Lakes ofregion, which I'm sure thatd,
any of you, and certainly in Michigan, driving across
the Michigan landscape, there's an awful lot of marginal land
that was taken out
and has been reverted to successional systems on the
order of anywhere from recently abandoned to 50-100 years old
at this point.
reconverted. And that land could also be
at least of any comprehensive Asanalysis of the availabilitye,
of those lands. But at least an analysis
that was done over the period of
somewhere on the order of 19812 million hectors of landas
that had reverted from cropland to forest.
And forest is defined as
it takes about 20 years 1for a 10% cover of trees,
to come into an abandoned agricultural field, so this
is, I think, a big underestimate
and could be converted of what's actually available
perhaps to native systems, to cellulosic crops,
perhaps to a variety perhaps to planted switch grass,
that we'll have to think about of cellulosic feed stocks
So the problem, of course, as we think about these issues.
as we think about the impacts wof ethanol, in a sense,at
it's simply business as usual but larger, with all of the
attendant environmental problems
today's agriculture, that are associated with
to various pesticides that enter waterways, to impacts
on the trace gas content
and biodiversity issues. of the atmosphere,
sustainability issues that So there are also some huge
with respect to grain ethanol, most of us recognize
should not be the case that may not be the case,
So cellulosic systems we have the opportunity to add
perennially to U.S. cropping
than we currently have. sSo the perenniality simplyy
meaning planting crops that are not tilled every year,
not planted every year, not nurtured every year in the
same way that annual crops are, and so we have the potential
to install these grasslands or woody crops in places
that are now farmed marginally, and that can provide
a lot of benefits that we're not now seeing.
Those benefits including those
diversity, such as effects that come from landscape
in particular, on insects, beneficial insects
effects on wildlife and effects on climate stabilization.
And that's what I'm going to talk about in much of this
next portion of the talk--
in adding to the mitigation portfolio for global strategies?
So I want to take a big picture here first, and then I'll
zero in on some research that we've been undertaking for the
past 20 years, or so, at the biological station.
But to set the stage, I need to talk first about--
This is a graph that everyone is familiar with.
It shows the long-term rise of atmospheric CO2 and
our game plan, ultimately,
at somewhere in this range here, is to keep CO2 levels stabilized
at the midpoint, IPCC scenario, witone of the conservativeange
scenarios, showing that where the trajectory is to be
way outside of those bounds.
levels stabilized, whatever current level we're at the time
that stabilization is effective,
the global CO2 balance. iSo if we think about thet
contemporary global CO2 budget, we can categorize different
sinks and sources as are done here.
So we have sources as being emissions from fossil fuel,
emissions from deforestation, as the two principle sources
of CO2 to the atmosphere. So we have somewhere on the
order of 9.1 pentagrams of CO2
CO2 carbon, being added bto the atmosphere annually.e,
That carbon is being removed
of 2.2 pentagrams, by ocean, from the atmosphere at a rate
in the ocean, and 2.8 pentagrams being taken up
by terrestrial vegetation and soils, and staying
in the terrestrial vegetation and soils, which leaves
a difference of 4.1 pentagrams, that is the atmospheric
loading rate for CO2
And when we think about stabilizing CO2, what we need
to think about is how do
so that we're not longer adding we CO2 to the atmospherero,
that stays there. We'll be adding CO2
to the atmosphere, of course, but we'll expect that CO2 to
be removed from the atmosphere
stabilization ultimately results on an annual basis, so that
increase going to zero. As you can see, we're going the
wrong direction at this point.
we've increased this term Just iby over 25%.ecade,
No surprise.
in all of this? Well, agriculture has several
roles to play.
for stabilizing atmospheric CO2 Iinto three broad strategies,s
we can think about reducing fossil fuel consumption
by improving efficiency,
sources, such as biofuels, by developing renewable energy
CO2 sinks we and sequestration rates.ing
And, of course, many geologists think it's possible to store CO2
in geologic reservoirs, perhaps in aquatic reservoirs.
But the more practical
is possible now, or that sequestration that's certainly
is that sequestration of carbon that was lost at some point
in the past, into soils and into long-lived plants.
And then the third major
greenhouse gases. There are other greenhouse gases
other than CO2 that are in the
that are naturally occurring, atmosand that agriculture,etic,
as I'll show in a few minutes plays a huge role in regulating.
So let's think about
for sequestration in ag systems. carbon loss and the basis
sequestration in agriculture And the potential for carbon
of carbon when agricultural lands were initially converted.
The exact same processes
clear tropical rain forests. that are going now when we
we lose carbon from the trees Wand above-ground vegetation.d
And that occurs universally,
of about 40-60% is lost acrosover 40-60 years. rate
This is known from the 1950s. It seems to be one of these
rules of thumb
much no matter where you are. It's possible to calculate.
There is some 54 pentagrams from an original 220, or so,
pentagrams that was lost
So that means that there's in this way.
that carbon and taking it out of the atmosphere and storing it
in soil, if we can develop the
And the no-till technology is, technology to do that.
strategies. of And the calculations,main
the conservative calculations,
on the order of .3 to .5 is that we can remove somewhere
Somewhere around 10% of the current carbon loading rate in
the atmosphere is possible to,
from the development of soils asthat store more carbon.ion
But there's a 54 pentagram cap. That is, we're not going to be
able to recover more than was originally lost, and probably
we're only going to be able to recover some proportion
of that, maybe 50% of that. Eventually this soil saturates.
That saturation occurs somewhere
after the technology on the order of 50-100 years
Now CO2 is not the whole story, is of course.d.
We also have these other gases. The other biogenic gases,
those gases that are produced by microorganisms in soil
in native, as well as managed ecosystems, include
nitrous oxide and methane.
to the radiative And those are also adding
Those also offer an opportunity to stabilize the radiative gases
in the atmosphere.
methane and nitrous oxide, Those two gases in particular,
exponentially now, as is CO2. This is a 2,000 year history,
mainly from ice forests for carbon dioxide, which is in red
here, and you can see that the
as well as the nitrous oxide, methwhich is in black,lue,
are both tracking the same sort of trend.
Now why are those interesting?
in quantities in the atmosphere that are a fraction of those
quantities that are represented by CO2, but they have
an interesting feature. They have a much greater impact
on a molecule by molecule basis than does CO2.
So the global warming potential,
chemist's way of comparing the which is an atmospheric
of any gas against some rreference gas is much highere
for methane and nitrous oxide than it is for CO2.
So by definition, the global
The usual IPCC way of calculating the impact of these.
is over a 100-year time horizon.
lifetimes, so you have to Thconsider the amount of timeric
you're making this
Methane has 23 times the impact impaof CO2.mate.
Nitrous oxide has 300 times the impact of CO2.
So what that means is that
one kilogram of nitrous oxide avinto the atmosphere of
is equivalent to avoiding the emission
of 300 kilograms of CO2.
nitrous oxide has a big impact So avoiding a little bit of
the CO2 equivalent burden on thof the atmosphere. say
So if you think about where nitrous oxide or methane
come from and how they get
we can define that the major into the atmosphere,
are agriculture. anthropic sources of these gases
about 55% of the methane that is currently produced by humans
is from agricultural activities,
Nitrous oxide, about 80% and about 45% from industry.
and a much smaller percentage comefrom industry.ture
That becomes interesting
in carbon equivalents what the when you total up
It's possible to calculate then tothat there's somewheree.
on the order of 3.2 pentagrams
being emitted to the atmosphere from human activities, a large
part of this is agricultural, which suggests that agriculture
could play a strong role
of these radiative gases in mitigating the buildup
And it gives us the opportunity then to think about the CO2
budget of cropping systems, not just in terms of energy balance,
as is more common in bioenergy
of the total CO2 equivalent accounting, which includes these
other gases, as well as carbon. And so, we can think about
sources of global warming potential and a cropping system
that's not just the carbon
sequestration into the soil or carbon decomposing and
releasing its CO2 in
it's burned in a vehicle, but also the other greenhouse
gases that are involved.
as a benefit, if you will, It allows us to count that
So what are the major sources onof global warming impact.
and fuel crop ecosystems? There's fuel use, of course,
that's a no brainer.
which is the basis There's also soil carbon change,
There's also for carbon sequestration.
Nitrogen fertilizer takes a fair nitrogen fertilizer.
It takes, in fact, a fair amount amount of energy to produce.
And the process of producing of methane to produce.
releases CO2. bySo there's a CO2 costess
for nitrogen fertilizer that's
carbon balance. a buThere's also a lime.m's
The agricultural lime that we add to cropping systems
is a carbonate, and that
by acid over the course caof the cropping season,ed
turns into CO2. So there's another source
of CO2 in the system. And then, of course,
there's also nitrous oxide flux and the methane flux.
So I want to use as an example
conducting at KBS over the past so20 years and bring you up.n
Some of you may have seen some
I'm sure haven't. of But I want to presentyou,
some updated data.
as part of the LTER site there, a series of cropping systems
that are arranged along a management intensity gradient,
ranging from annual grain crops,
high intensity, through perennial biomass crops,
which would be the equivalent of
Through unmanaged communities, the cellulosic biofuel system.
old field, which is simply including an early successional
when the plots were established. a field that we let go in 1988
prairie per se, about 50% of the species are exotics.e
The native plants are plants are
And we also have midsuccessional grown in an unmanaged setting.
abandoned 50 or 60 years ago, and then an old growth forest.
We have some postage stamp-sized
cut, so allow us to use these wood for reference points been
for what was probably the pre-European settlement fluxes
for these gases.
carbon change over the first So we can think about soil
As you would expect, there was ten years of this experiment.
conventionally tilled system, noand some 30 grams per meteral
squared per year was gained in the no-till, which is
actually the median rate
in no-till systems. But the interesting piece here
is that the poplar and alfalfa
as well. systems both sequestered carbon
because they're also no-till, Which makes right?ense, simply
You plant these things
and till them every year. They're also adding woody roots
to the system that the
so we might expect them to be heat least in some cases,t,
to add more to the soil carbon
But more interesting is this early successional system,
which is adding almost twice
than is either of the other perennial biomass systemsl
and twice as much as a no-till system.
And here is a probably an effect
more diverse plant material ocoming into the system, ande
the microbes are having a tougher time of breaking it
down on annual basis. Now here we have an example
of the saturation of this,
from 60 in the first ten years in that the sequestration goes
11, or so, in the midpart down tof the century.s than
And then it goes to zero
Old growth forests are in the old growth forests.
Their carbon balance by definition at equilibrium.
As a result, we have no sequestration potential
in a like successional forest.
sequestration to disappear We can expect soil carbon
whatever kind of perennial crop aftewe're putting ins of
without tillage.
nitrous oxide portion of this for a couple of minutes as well.
And nitrous oxide is measured in a very simple minded way.
It's very labor intensive.
to do this at this point, but it simply is a matter of putting
a box on the soil surface and collecting the gases
that are emitted by that soil over the next 30 minutes
to two hours, and then plotting a flux
based on the concentration
one to two hour period. When you do this, and we'vet
had the luxury of being able to do this for almost 20 years now.
I think we have the longest continuous record of N2O fluxes
from cropping systems now in the world.
But when we do this, we see that
and that the annual cropping there are very strong patterns,
equivalent rate that are about systems are producing N2O at
in the unmanaged systems. tSo even the reference system
in the native forest, which is
and mid-successional systems slightly higher than the early
of a 1/3 to 1/4 of those have rates that are on the order
cropping systems. Perennial crops are different,
based on whether nitrogen is available.
Alfalfa, which is a legume, has N2O fluxes that are equivalent
to those from the annual
sense if you think about cropping systems, which makes
on nitrous oxide production. what are the major controls
called de-nitrification that results in the microbes
producing N2O from nitrate. There's a lot of nitrate
circulating in these systems. So there's a lot of
available substrate for the denitrifying bacteria.
Poplars on the other hand are extremely efficient
from a nitrogen utilization stand point.
You would expect it,
that nitrous oxide fluxes therefowould be low.predict
In fact, they're even lower than they are in the unmanaged
systems, which suggests that there's a real potential
for a cellulosic perennial
this service to a landscape bin which it's planted.
That is, to avoid the emission
to a crop that was there of nitrous oxide, as opposed
Early successional system is similar to a prairie system,
if you will.
nitrous oxide fluxes that aren't It also has very low
Now CH4 oxidation, and this muis a process whereby methanes.
is taken out of the atmosphere
in soil, about another class and -- by methanatrophs
use methane as an energy source. of bacteria that in this case
globally because about 30 Mterograms of methane per yearng
are removed from the atmosphere by soils.
And that removal occurs mainly
mainly in forests. in undisturbed ecosystems,
you convert these native systems It turns out that when
you effectively shut off to agricultural use,
And that is important globally, mebecause of then.
atmospheric burden of methane in the atmosphere.
We're adding about 44 terograms per year from all sources.
Soils are taking out
So if soils were not taking out 30 terograms, we would have
an atmospheric burden that would be 44 plus 30.
And so the soils are responsible
concentration of methane for keeping the atmospheric
it would be otherwise. at a much lower level than
doing to it though? We're shutting it off
with conventional agriculture.
is there a potential for So we're asking the question,
somewhat differently, perhaps cellulosic crops could
play a role in this to produce
that would be good at pulling methane out of the atmosphere.
And we see that there isn't much here that suggests that
we have that capacity with most cropping systems.
And it's not until we enter our midsuccessional system,
native vegetation, 50 or
to get significant recovery 6of that methane oxidation.
So there is a potential for using cellulosic crops to
also lessen the methane burden. Okay, so how do you put this
together in a total system
in any case, to ask what are context at the field scale
these different cropping systems the different potentials across
It's possible to build tables. for doing this mitigation.
five or six similar tables I'm going to go quickly through
all of these systems in it. hereBut I want to spend just has
a minute talking about the first
better the next set of numbers. eSo in a conventionally tilledck
system, a corn, soybean, wheat
in soil carbon, so there's rotation, there's no change
There is no contribution no soil carbon contribution.
or the CO2 burden in atmosphere from soil carbon changes in
a conventionally tilled system. There's about 27 grams of
CO2 equivalent per meter squared
accountable to that system per year added to
that's applied. baAbout the equivalent amountzer
based on the agricultural lime
This is over a ten year period, actually over 20 year periods
now.
16 grams of CO2. There's a fuel cost of around
of around 52. AAnd a net mitigation,t
a net credit for CH4 oxidation. There's a little bit going on,
but that gives us a total value of around 100 units
of CO2 equivalents
So far it's at equilibrium. bThere's no annual change and.
nitrous oxide is the largest
So if we switch to a no-till source of CO2e in this system.
net increase, this net system, we can reduce this
to radiative forcing in the atmosphere by almost 100 units,s
based almost entirely on
And we count this as a negative, the soil carbon sequestration.
out of the atmosphere beand storing it in soil.on
There's a little bit of savings on fuel because no-till systems
use a little bit less fuel. But importantly, there's no
differences in nitrous oxide. The organic system has a net
somewhere in between the no-till
largely because we're getting a little bit of soil carbon
sequestration, which is a surprise, for other reasons.
But we have no inputs from fertilizer or lime.
But interestingly, the same burden of nitrous oxide as I
showed in the earlier bar graph.
change this to a more favorable mitigation scenario, where we're
actually getting mitigation in this case, as a net effect.
So the alfalfa is sequestering
no doubt because it's perennial and the roots are in the system
and decomposing in place. They're not replanted each year.
No nitrogen fertilizer. We are adding a fair amount
of lime to counteract acidity.
compared to the annual crop existence, but again the same
amount of N2O leading to some mitigation.
The poplar trees bring this to a very substantial
net mitigation potential
Minus 105, so we've got almost in these systems.
difference between the poplars a 200 gram CO2 per meter squared
tillage system. So that tells us that
we're on the right track here with providing some mitigation
services that are not available in the annual grain systems.
And again, it's partly because
or restoring in carbon. But also notice in here,
we've cut down the N2O burden by almost a factor of six.
The successional communities
the most power are the ones that really provide
with almost a minus 200 twice out of the poplar.
So this is effectively
You could also think of this a native prairie.
That is, there's no reason as a perennial grass.
this shouldn't be any different from a C3, C4 grass mixture,
or even a complete
That's one of the questions swe're investigating in
the center is, does it matter that this is a mixed species
community versus a monoculture
Switch grass is a native prairie switch grass community.
a single species, may have some effects, as well as some risks,
that we wouldn't see
But importantly here, the net effect drops off,
as you might predict, because of
to some midpoint here. the soil carbon sequestration
by the time you redevelop the late successional forest.
Okay, so it's possible to reconstruct a graph that looks
something like this for a total.
the cellulosic biomass crops. TThese three systemsy
here in the middle. The alfalfa, the poplar and
the early successional systems. So quite apart from any benefit
that is obtained from substituting the carbon
from these systems
there's this other aspect for to their carbon economy mix,
that needs to be kept in mind as we think about what's
the best design for these cropping systems in the future.
There is also a co-benefit. And this is one of the
interesting, and I think very potentially valuable aspects
to these cellulosic systems,
these systems are perennial, as well, and that is because
the whole year. They're growing the whole year,
in effect, whenever the temperatures are above
a certain point, there's still
means that there's still the photosynthesis going on, which
which means that any nitrate potential for nitrogen uptake,
might otherwise wash through that might be in the soil, that
for plant uptake. thAnd in fact, we see that.ble
This is nitrate leaching
we've had monitors in the ground over an 11-year period, where
nitrate out and measuring the water flux by modeling,g
and showing that conventional systems are leaching somewhere
on the order of 500 kilograms of nitrate over this period
per hector. But the cellulosic systems
are very low. In the case of the poplars,
we can't detect any leaching
We don't have the data yet under the poplars.
This is a paper that's just now for being assembled.ms.
So there's this other benefit that might also accrue
from building a landscape that
but also some mixture inof perennial crops that will,
provide services that we're not getting now with these
almost monoculture
And that's and biculture landscapes.
We're aiming to design what we're aiming for.
So I want to take five or six minutes to just to review
what we're doing in the GLBRC with respect to sustainability.
And some of this ties into
but others of it what I've been talking about,
So our overall objective is quite different.
and bioenergy pipeline is to support the biomass
that are economically viable and environmentally
responsible.
interested in carbon neutrality and greenhouse gas mitigation,
and also in quantifying the ecosystem services that could be
provided by biofuel landscapes. Now the way we're approaching
this is from a hierarchy
At the first level, we're looking at the development
of novel production systems.
on crops that now exist, or Tthat will be developed as partd
of the GLBRC activities in other research areas.
So eventually, we'll be having
then, this wheat that we have addnow or improved varietiesout
of this wheat that we have now, that we'll be able to enter it
into the system.
to production goals. But we have two aspects
the novel production systems One of them is defining what are
productive, that will provide the suite of services
that we want to encourage from these systems.
We can also think about what are
interactions that might lead the improved microplant
of these novel systems. tAll of these systems havee
environmental responses and economic responses.
The environmental responses are the biogeochemical responses
that I've already described through the statisticians
at KBS, nitrogen and carbon cycling in particular.
There are also biodiversity responses.
That is what is the response
or a microbial community of an insect community,
or 20 years of poplar, to 20 years of switch grass
rotation. veSo there's going to be somean
responses there that will be
Then, of course, there are important to quantify.
as the economy of these systems ewill be very different,
depending upon a whole host of attributes.
So we'll take these responses and use them to inform models
at different geographic scales
with information on what are to eventually provide us
designs that we could put out tinto these future agriculturale
landscapes, and think about what
impacts of these designs. And that will help to inform us
as to what sort of additional changes we need to make
to the production systems in order to tweak the outcomes.
And eventually, it should provide us the information
needed to design the optimal
who, as Pete Nowak was speaking cto me this morning about,s,
how do we paint these landscapes
the ecosystem services that can be provided by these systems.
So a quick word about the approach we're taking to examine
all of these processes. As we've arranged a series
of ecosystems and series
along a gradient of cropping systems
to low input high diversity. of high input low diversity,
being continuous corn, With one end of the spectrum
the total biomass of the crop mato a restored prairie, atfor
the other end of the spectrum.
systems, including poplars, early successional switch grass
systems, as well as a more
It's not benign, but a more environmentally responsible
system than continuous corn.
different portions of the And project, each of thoseese
different circles that I had
examining specific hypotheses. up on the previous slide were
through all of these, but rather And I'm not going to read
With any improved microbial plant interactions program,.
we're looking at both organismic level, as well as
genomic level responses to improving the plant,
improving the ability of plants to take up nitrogen, to be more
nitrogen efficient, for example,
sequestering by manipulating or perhaps even more carbon
in that system. Biogeochemical responses
are not just looking at the carbon cycle, but also
water use and nutrient loss,
Biodiversity responses are as I've already eluded to.
including microbial lbiodiversity, but from the
standpoint of what we see,
predatory and parasitic insects and their control in landscapes.
Bees, which provide pollination services, of course.
Game and song birds,
And all of these provide very quantifiable, and in some
respects, ecosystem services. And part of our challenge
in the economic portion of this is to quantify those ecosystem
services in ways that can inform
currently being informed. pAnd so in the economic arena,re
we're interested in thinking
and the implications of that about crop area change forecast
going to be seeing, so that if we build scenarios in which
we favor grain based alcohol, for example, that's going
to have a very different effect on land change, than one
in which we build policies
cellulosic landscapes. that incentivize
in terms of ecosystem service Wevaluation, in particular.at
And then, the modeling component
The objective is to build is a framework that allows uss.
to run scenarios to forecast, what are the outcomes of these
different policy decisions, these different behavioral
decisions that we're making as a society, and how that
will effect, eventually,
in the atmosphere. the CO2 concentration
This is my last slide. That runs from the modeling.
level, where we're using The modeling runs from the site
carbon and nitrogen biophyand plant growth.redict
All the way through landscape,
global levels, where we're using regional, national and
to ask what does putting this inmuch cellulosic biofuelels
into the landscape, what effect does that have
on climate stabilization
knowing what we know about on CO2 stabilization,
about population growth, land use change,
and about climate change about technology innovation
So the integrated assessment during that period, and so on.
used to build the IPCC scenarios models are those models that are
over the next century. that predict CO2 concentrations
in the center, who has built And we have a group involved
using those models to predict thesthe eventual outcome.ll be
So I'm going to stop there and
in whatever time is available. would be happy to take questions
very briefly by the comment that what we're talking about
with cellulosic systems is very different
from what we have now with our current generation
of ethanol plants.
continuing the business as usual In that, we're not talking about
but we're trying grain ethanol production,
shift the potential scientific to shift the discussion and
to the cellulosic arena, because understanding of the outcomes
The environmental impact of cellulosic systems in the future
are just orders of magnitude
grain-based alcohol production different than they are for
extent, are business as usual. systems, which, to a very large
to those systems. You saw that in the conventional
systems that I had up there,
was better, the organic system in fact, the no-till system
that were good. had So the low inputtes
could improve those.
systems to net mitigation. But none of them send those
that send them to net mitigation The only systems
perennial and produce are mabove-ground biomass,t are
as opposed to seeds.
Thank you very much. So I'll stop there.
Thank you, Phil. ( applause )
But the other thing I'll say We do have time for questions.
is we have some treats before I forget to say it later,
to give people some more time anto meet each other and tords
talk to Phil
So questions for Phil. or anyone else who's here.
Thanks for the very And interesting talk.und.
You've got a slide in there that showed that emissions
from deforestation are actually declining and, of course,
we've been reading Science
about that with biofuel. Magazine about concerns
charts with your early And then, some of your other
it seems like we might want succeto minimize carbon,mean,
actually manage some of our forests for early succession.
And what you hear from a lot
What are some of your thoughts of folks is we need old growth.
And what are the next steps to getting from the corn economy
to the biomass economy, in your eyes?
Your last question is the hardest, of course, and I don't
know if I'll be able to address that effectively.
But it's one that we need to think about
addressing effectively. Your first question about the
deforestation adding less CO2 to the atmosphere now
than it did in the 1990s. I was also surprised by that.
It doesn't take into account
that's currently happening the additional deforestation
This is a 2000-2006 period because of higher food prices.
It was published in PNAS of analysis.
My expectation is that when we last year.
that it will probably show do the total 2000-2010 budget,
because of the clearing that's the same or an increase,
because, in particular, because of the oil palm clearing
that's going on in Indonesia. We have peat soils
being exposed to oxidation
contents, because they're being cleared for the oil palm
production. So I wouldn't put a lot of stock
in that small decrease
The issue with respect in deforestation at this point.
You know, we have a lot tof successional vegetation in.
the Great Lakes region largely
that are no longer, at least because of marginal lands
not considered profitable enough under 2005 grain prices, were
Now that may well change. And we're seeing more marginal
land coming under production
just because this year I understand,
And you might predict that. But there should be, and one of
my hopes, is that we can inform policy to the point that
eventually those systems
with higher grain prices, thstill be profitable for thele
standpoint of producing grain,
from the standpoint theof providing above-groundable
cellulosic material as feed stock.
And it might be even more desirable and profitable
if we figure out a way
to pay for those services that to provide incentives to farmers
for those services, thothe pollination services,ing
the clean water services, the carbon sequestration
services, and so on.
will stay, regardless of whether those systems
are cropped annually, that is, harvested annually,
if they're done right.
them probably in the fall, That means you've got to harvest
with enough cover left over afor the wildlife, the birdsem
in particular, over winter. But there are ways to do that
in a sustainable way, I'm convinced.
Now, I'm not sure that gets at
to that. your question with respect
over time with harvesting and replanting, do the emission
and sequestration approach
or do they stay higher those of a mature forest,
Yeah, that's a great as the initial planting?
Did everybody hear that? question.
do you expect a decline in their mitigation potential
over time in the same way that you lose that mitigation
potential with a natural forest,
And the quick answer is, with an old growth forest.
I would expect the N20 levels to stay just as low
as they are now.
in the old growth forest. SimplyWhether we can buildo low
methane oxidation capacity
is yet to be determined. in those systems
been in place for 20 years. TWe haven't seen that capacityly
yet, but we know that a 50-year-old field
has half of the capacity
So maybe in another 30 years, that poplar stand will provide
the additional oxidation, methane oxidation capacity
that is not now showing.
sequestration in soil, With respect to carbon
at some point. we would expect it to plateau
going to build up higher than the old growth forest, which
in our case around 3% carbon. We've got around 1.4% carbon
in the poplars now. Probably it will max out
at 2.0% is my guess.
studies of biomass poplars Again, there are no ecosystem
that we've got here. that are longer than the ones
of learning what those So we're really at the edge
( inaudible ) s>>...is not including,
especially an old forest, the both above ground
and below ground carbon pools.
you talked about the grades, It seems like the most
( inaudible ) bu>> So the question was, whyls,
aren't we including the pools of carbon in the forest that
are now in place as part of the accounting.
And the answer is that
in pools to calculate the impact we're interested in changes
or CO2 sequestration. Now, it's not to diminish
the value of those old forests
that they have. And this is the whole basis
for deforestation being a flux. Were we to cut those forests,
then they would turn into a flux
the atmospheric burden of CO2. and they would increase
there is no net change But as they are, at equilibrium,
in carbon storage. on a year-to-year basis
of old growth. That's the definition
either positive or negative Animpact on mitigationt,
or on the CO2 burden
So we don't count it in the atmosphere.
Would you speculate what for that reason.
from climate change might be on ythose balances across systems?
Is it likely that it will just move things up and down
or that they'll be
Yeah, that's another differentially affected?
And that's what we're hoping tough question.
Climate change in the Great Lakes region is happening.
We're seeing an increase
on the east side of the lake. We're also seeing changes
in snowfall duration
Of course, we're seeing the early onset of spring
relative to recent history. And understanding the impacts
of those changes
biofuel landscapes to produce oas much as they could producee
in today's climate, it's an open question.
And the different models
aware, the different GCM models are sare showing differentou're
precipitation changes, depending
It's very difficult to predict on which model you're using.
We see warming, for sure, theand that's going to haves.
a big impact on lake level
because there will be a lot more transpiration happening,
so a lot more water vapor that
the groundwater and in the lakes would otherwise have ended up in
back in the atmosphere. But beyond that prediction,
I don't know
Certainly, however climate if we can go very far.
in general, they're going chanto have a similar effectems
on these cellulosic systems,
And that is mid-growing season with one exception.
for two of the last five years, will have a much lesser impact
on a perennial system than they will on our corn
and soybean systems.
that's a good point. And so in that sense,
systems, the cellulosic systems should be buffered from at least
that kind of variability, the intra-annual variability
in climate. >> So maybe we should take one
more and go out and have some coffee.
Two more. >> Two more, go ahead.
Sorry.
much publicized study about prairie biomass, and also have
seen your results, and wondered,
global impacts and net benefits tin terms of global warming
impact, but they just aren't
And I wondered if at Kellogg very productive.
you're familiar with, if people have tried fertilizing
either the poplars
old fields to see if you or say the early successional
benefits, but also greatly can still get most of those
Yeah, great question. So the question was?
with native prairie systems,
thus far, and the advocates the dafor those systemsblished
are advocating systems
as the monoculture, or even tbiculture grass systems.
And, it's true. On one of those initial slides,
I had productivity values for grasslands.
And those are grasslands that one might find in central Kansas
or in the Great Lakes region, which are on the order
of three to four metric tons
which is about half of what you could get, probably.
We don't know this for a fact,
the experiment now. But probably, if we were to get
the same switch grass productivity that others have
found in a recent PNS paper in farms across South Dakota,
and Nebraska and so on, we would get about half
the productivity
Now we do have fertilized inold fields at KBS, and wed.
can show that we can boost
to around seven metric tons the proper hector.f those
So we can get equivalent yields from the old fields
as we can from the monoculture
which is really interesting. switch grass,
is that interest have been Now the down side of that,
the U.S., all over Europe, a lot of experiments all over
looking at the impact of as well, in the past 15 years
And in general, fertilizing fereduces plant biodiversityy.
in native prairie.
would be greater productivity, And so the trade off there
And that's why those who are but less plant biodiversity.
haven't gone the next step, in saying, well what happens if
we fertilize those grasslands.
We know that. Yes, yoBut at what cost.ctivity.
If the aim is to increase biodiversity at the same time,
you're increasing cellulosic
ask how do you balance feed stocks, then you have to
the increased productivity. That's one of these trade offs
that are going to be true in any kind of analysis
and important to understand.
Sort of two parts. One final question, I hear?
research, I'm just curious, how generalizable that is?
You showed at the beginning all these marginal lands
that could be utilized
the eastern U.S., for example. with different soil types in
if in your analysis, you're Algoing to be looking at, anding
making comparisons to sort of second growth forests
as long-term sinks, sort of these general land uses
versus the biomass production,
from that first map you showed, becauseabandoned landsagining
that could be reincorporated, you know, south eastern Ohio.
I'm from Ohio, so I'm picturing kind of poplar plantations
harvested every 20 years there, versus the second growth forest
that's probably there now.
landscape, and if those are getting converted, you might be
gaining, you know, you can
but the above ground processes store extra carbon in the soil,
has really changed. >> You might have
equivalent productivity for either of those two systems,
poplar or secondary forests,
I should say unfertilized depending onpoplar.eir managed.
Right now, our unfertilized poplar, and our poplar is
unfertilized, because we put it in as a biofuels crop
back in 1988, when the thought
only be growing biofuel crops on marginal land, and farmers
would only be interested in them
any inputs. beThat is to say that theye
didn't really have much value,
So we decided at the outset to manage these
as effectively unmanaged, but initially planted poplars.
And the productivity
It's about 10 metric tons in thper hector per year.high.
But a successional forest,
you might expect a similar once it gets to a certain point,
some fraction of that. sort of productivity,
you know, what trade offs Theare you willing to make.k,
Do you really want monoculture
south eastern Ohio versus successional forests that might
be a little less productive,
other biodiversity services that a monoculture poplar can't.
So I think those are exactly
we need to consider, the kind of questions
optimal landscapes for biofuels. as we think about what are the
I shouldn't say I methere's no question.on--
There's little question that we're going to be moving
into this economy,
And we now need to make choices. we've already started.
equivalent of Iowa corn fields Well, we really don't want the
in successional forests coacross the U.S., plantedw
to a similar woody monoculture. So we need to be having
the discussions and be thinking about how to quantify
the biodiversity benefits in addition to the strict
biofuel benefits. As far as KBS being
generalizable, we're looking
in these systems. And these processes occur
everywhere. Because we're comparing systems
we would expect the same
the same sort of differences sort of comparisons to hold,
you're on a KBS alpha soil to hold, no matter whether
of about a meter per year, with a rainfall
on less soil with a little bit less precipitation.
The relative differences
So not exact, of course. should be the same.
and invite everyone to come on >> I want to thank Phil again,
and talk for a while. ( applause ) outside toome coffee