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(Advances in agronomy 105) donald l sparks (eds ) advances in agronomy academic press (2010)

Advisory Board



University of Kentucky

University of Minnesota



University of California,

Texas A&M University

Emeritus Advisory Board Members



University of Delaware

Iowa State University



North Carolina State

Cornell University

Prepared in cooperation with the
American Society of Agronomy, Crop Science Society of America, and Soil
Science Society of America Book and Multimedia Publishing Committee







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Numbers in Parentheses indicate the pages on which the authors’ contributions begin.

S. Anthony (83)
ADAS, Wolverhampton, Woodthorne, Wolverhampton, United Kingdom
Jeff Baldock (173)
CSIRO Land and Water, PMB2, Glen Osmond, SA, Australia
R. Bol (47, 83)
Biogeochemistry of Soils and Water group, North Wyke Research, Okehampton,
Devon, United Kingdom
Bhagirath S. Chauhan (221)
Crop and Environmental Sciences Division, International Rice Research Institute,
Metro Manila, Philippines
H. Cover (117)
Vistronix, Inc., Portland, Oregon, USA
J. A. Delgado (117)
USDA-ARS-Soil Plant Nutrient Research Unit, Fort Collins, Colorado, USA
Matthew Forbes (173)
Natural Resources Branch, Department of Conservation and Environment,
Locked Bag 104, Bentley Delivery Centre, WA, Australia
P. Gagliardi (117)
USDA-ARS-Soil Plant Nutrient Research Unit, Fort Collins, Colorado, USA
S. J. Granger (83)
Biogeochemistry of Soils and Water group, North Wyke Research, Okehampton,
Devon, United Kingdom
C. M. Gross (117)
USDA-NRCS, WNTSC, Beltsville, Maryland, USA
P. M. Haygarth (83)
Centre for Sustainable Water Management, Lancaster Environment Centre,
Lancaster University, Lancaster, Lancashire, United Kingdom



E. Hesketh (117)
USDA-NRCS, WNTSC, Amherst, Massachusetts, USA
David E. Johnson (221)
Crop and Environmental Sciences Division, International Rice Research Institute,
Metro Manila, Philippines
E. Krull (47)
CSIRO Land and Water, PMB2, Glen Osmond, Australia
H. Lal (117)
USDA-NRCS, WNTSC, Portland, Oregon, USA
E. Lopez-Capel (47)
The Swan Institute, University of Newcastle, Newcastle upon Tyne, United
S. P. McKinney (117)
USDA-NRCS, WNTSC, Portland, Oregon, USA
P. N. Owens (83)
University of Northern British Columbia, Prince George, British Columbia,
W. A. Payne (1)
Assistant Director for Research, Norman E. Borlaug Institute of International
Agriculture, and Professor of Crop Physiology, Texas A&M University System,
College Station, Texas, USA
M. J. Shaffer (117)
USDA-ARS (Retired), Fort Collins, Colorado, USA
S. P. Sohi (47)
School of GeoSciences, University of Edinburgh, Edinburgh, United Kingdom,
and Department of Soil Science, Rothamsted Research, Harpenden, Herts, United
Murray Unkovich (173)
School of Agriculture, Food and Wine, The University of Adelaide, PMB 1, Glen
Osmond, SA, Australia
S. M. White (83)
Cranfield University, Cranfield, Bedfordshire, United Kingdom


Volume 105 contains six outstanding reviews dealing with nutrient cycling,
soil and water resources, climate change, and crop management. Chapter 1
is a thought provoking commentary on the impacts of biofuels on sustainability of soil and water resources. Chapter 2 discusses the potential effect of
biochar on climate change and carbon cycling, crop productivity, and
resource management.
Chapter 3 is a thorough review on water pollution from intensively
managed grasslands. Pollution pathways and ways to minimize contamination from them are also discussed. Chapter 4 is a contemporary review on
the use of an innovative GIS Nitrogen Trading Tool for conserving and
reducing nitrogen losses in the environment. Chapter 5 discusses the impact
of harvest index variability of grain crops on carbon accounting, with
application to Australian agriculture. Chapter 6 deals with the role of seed
ecology in enhancing weed management in the tropics.
I appreciate the excellent reviews of the authors.
Newark, Delaware, USA




Are Biofuels Antithetic to Long-Term
Sustainability of Soil and Water
W. A. Payne*,†


1. Introduction
2. Some History
2.1. Ethanol as a fuel
2.2. Soil and oil
2.3. Charting our future in the past
3. An Overview of Biofuels
3.1. Ethanol
3.2. Biodiesel
3.3. Cellulosic ethanol
3.4. Biofuel feedstocks and conversion to biofuel
3.5. Bioenergy and biofuel potential on a global scale
4. Sustainability Issues
4.1. Favorable economics?
4.2. Conservation of resources
4.3. Preservation of ecology
4.4. Social justice
5. Summary

Sustainability of biofuels is a contentious but old topic that has reemerged with
increased use of crops as feedstocks. There are vastly different land requirements for different feedstocks, and disagreement on the energy balance of their
conversion to biofuel. To be sustainable, biofuel systems should (1) have
favorable economics, (2) conserve natural resources, (3) preserve ecology,
and (4) promote social justice. With the possible exception of sugarcane

* Assistant Director for Research, Norman E. Borlaug Institute for International Agriculture, Texas A&M
University System, College Station, Texas, USA
Professor of Crop Physiology, Texas A&M University System, College Station, Texas, USA


Advances in Agronomy, Volume 105
ISSN 0065-2113, DOI: 10.1016/S0065-2113(10)05001-7


2010 Elsevier Inc.
All rights reserved.



W. A. Payne

production in Brazil, it seems unlikely that ethanol production from crops will be
economically viable without government support. Less is known on cellulosic
feedstock economics because there are no commercial-scale plants. Natural
resources that may be affected include soil, water, and air. In the United States,
agricultural intensification has been associated with greater soil conservation,
but this depended on retaining residue that may serve as cellulosic feedstocks.
The ‘‘water footprint’’ of bioenergy from crops is much greater than for other
forms of energy, although cellulosic feedstocks would have a smaller footprint.
Most studies have found that first-generation biofuels reduce greenhouse gas
emissions 20–60%, and second generation ones by 70–90%, if effects from
land-use change are excluded. But land-use change may incur large carbon
losses, and can affect ecological preservation, including biodiversity. Social
justice is by far the most contentious sustainability issue. Expanding biofuel
production was a major cause of food insecurity and political instability in 2008.
There is a large debate on whether biofuels will always contribute to food
insecurity, social justice, and environmental degradation in poor countries.

1. Introduction
The cacophony of responses to a recent New York Times article (NYT,
2009a,b) in which New Mexico Senator Bingaman suggested further
government help for the ailing ethanol industry illustrates what an emotionally and politically charged topic that biofuel has become (Table 1). One
can find similar spirited exchanges on biofuel articles at the Christian Science
Monitor, The Economist, and other newspapers. Some of the hot button issues
that biofuels and especially ethanol raise include patriotism, pro- and antiwar sentiment, terrorism, xenophobia, engine and conversion efficiencies,
food for the poor, environmental protection, fair trade, energy independence, urban vs. rural America, big oil companies, and government
spending of taxpayers’ dollars.
How can scientists possibly make sense of this when, after all, they
themselves are not free from partisanship (Clair, 2009; Guston et al.,
2009)? There is not even a strong consensus within the scientific community on whether the overall energy output from ethanol and biodiesel
production is greater than the input (Liska et al., 2008; Pimentel and
Patzek, 2005). Add to that all the other sociopolitical aspects, and one
truly has a (metaphorically) volatile mixture.
Because of the many biophysical but especially sociopolitical uncertainties and complexities involved, it should come as no surprise that, whether
for good-faith or simply politically motivated reasons, there are many
contentious views on the topic of biofuels and sustainability. In large part,
the topic is linked with that of global climate change, which itself is


Are Biofuels Antithetic to Long-Term Sustainability of Soil and Water Resources?

Table 1 Posted reader comments to New York Times article on proposed increased
support to the ethanol industry (NYT, 2009a,b)

I think this is a terrible idea, every single subsidized program has been a terrible
money draining failure from airlines to welfare. Basically we’re supporting
high commodity prices by pushing this plan. This hurts foreign competition
and disrupts food markets, we should not be burning food until we can end
world hunger. Of course there are also various environmental concerns, the
increased fertilizer runoff, by-products from factories and the stuff is less safe
than gasoline since it is less stable.
The claim that the problems of the ethanol industry are attributable to the
recession is dishonest. The ethanol industry is in terrible shape because corn
ethanol makes no sense economically or environmentally, and there is no
known method for producing cellulosic ethanol on a commercial scale.
Please do not prop up corn ethanol. The environmental consequences of
growing so much corn conventionally (read mono-crop, petroleum
intensive, chemical dependent agriculture) easily cancel out the benefits
of ethanol blends. Because we heartlessly treat food as a global free market
commodity exposed to the whims of speculation, ethanol production has
spiked corn prices and in classic domino effect caused the prices of other
staples to ride a roller-coaster as well. This has led to wide spread hunger,
food riots and instability. Congressmen, many of whom are deep in the
pocket of mega-agribusiness, need to step back for a moment and realize the
dangerous consequences of burning food as fuel.
Contact your Senators and Representatives and tell them that corn ethanol
fuel is a terrible idea both for the economy and the environment.
Wow! You mean the government mandated something without making sure
it was technologically and economically feasible first?
Ethanol uses up as much fuel as it is supposed to save or more, according to
recent studies. It makes us more dependent to foreign oil, raises food prices,
reduces gas mileage and engine performance, damages the environment. If
it wasn’t for. . .lobbyists, congress would have never given those
multibillion dollar corporations our tax dollars to subsidize this lunacy.
Corn-based ethanol is the ONLY renewable fuel that is available today and is
the foundation for the next generation ethanol (cellulosic) of tomorrow.
The notion that corn-based ethanol being the culprit for increased food
prices has been completely debunked, leaving the GMA and other
antiethanol groups with absolutely no credibility. America’s corn growers
have just completed one of the largest harvests of corn in our country’s
history, with an average of 154 bushels of corn per acre. With continued
improvements in agriculture, that yield is expected to double, ON THE
SAME AMOUNT OF LAND, over the next decade. This country MUST
continue to support corn-based ethanol to get to cellulosic and, more
importantly, to reduce our addiction to foreign oil.


W. A. Payne

Table 1


In addition to the economic failure of corn ethanol, the environmental costs
include using limited water supplies. Ethanol plants are more water efficient
than they were, but still have huge water requirements. According to the
Feb. 2007 Ethanol Producer Magazine it takes 150–300 million gallons of
water to produce 100 million gallons of ethanol. When the water tables are
depleted and we cannot get water for food crops, drinking and other
activities, where are the tankers of water going to come from?
I love how 99% of the people bashing ethanol have never driven a car with
ethanol (besides E10), but will quickly attest to how terrible it supposedly is
by pointing to bogus studies that use ethanol data in excess of 5 years old.
Besides, I’d rather buy my fuel from Farmer Bob down the road than some
sheik in the mideast that’s funneling money to terrorist organizations.
The price difference makes up for your lost mileage because of very large
subsidies and indirect costs that are paid by other consumers and taxpayers.
If you want to pay more money to Farmer Bob for ethanol, then by all
means do so—but pay him with your own money, not money confiscated
from others. And while you’re at it, add on a few bucks per gallon for the
environmental damage that you’re inflicting. In short is it not the myth of
‘‘renewable, corn base ethanol’’ that both science and the market place has
Ethanol from corn is not renewable because the energy inputs are roughly the
size of what you get out in usable liquid fuels, and the greenhouse gas
savings are nil. There is no scientific doubt about these statements, the
literature is full of them. There is also no doubt that cellulosic ethanol, if
made right, or the kinds of advanced biofuels Berkeley, Stanford and other
institutions are working on, MIGHT give true relief on the oil front and the
CO2 front. But no responsible scientist, economist or politician
(oxymoron) believes cellulosic ethanol or any other biofuel will be cheap,
even compared to $100/bbl oil, when all the costs are counted.
I challenge you to forego the tax subsidies and shift to a tax on oil, and a tax on
carbon, and let the market decide how well ethanol from corn can compete
with other fuels, more efficient cars, and less driving.
Corn also requires nitrogen fertilizing that is being blamed for increasing dead
zones in the Gulf of Mexico and elsewhere. If we want to get more than
10% of our vehicle fuel from corn etc. serious inroads in land and water
needed for food crops will have to occur. Biofuels are just recycling carbon
dioxide without removing on balance one molecule of that gas already at
levels causing major global warming effects. So biofuels really are just a
wheel spinning operation going nowhere in getting control of climate
The modern-day definition of agriculture can be said to be ‘‘the process of
turning oil into food.’’ Therefore we CANNOT base new generation fuels
on conventional modern agriculture.


Are Biofuels Antithetic to Long-Term Sustainability of Soil and Water Resources?

Table 1


To be optimistic, the goal of the work in Berkeley is to follow the advice Sean
gives above, namely to find a way to turn cellulose into sugar and alcohol,
just like termites or other organisms do it, without using large quantities of
land or water. Using basic biochemistry there is a good prospect we can do
this, but not necessarily cheaply. The late Prof. Alex Farrel was a strong corn
ethanol until he and his students here started churning out the disappointing
numbers on the low energy yields, the huge land, fertilizer and water
impacts of corn, and the lack of any greenhouse gas benefit. While there
certainly is promise of higher corn yields per acre, how much of that
increase comes at the expense of greater use of oil products for our
mechanized agriculture and coal-based electricity for irrigation? One of
Alex’ last articles was an Op Ed in the SF Chronicle about a year ago,
entitled ‘‘not more biofuels, better biofuels.’’ Until we get there, we should
not be subsidizing and earmarking any biofuels, particularly as all of these
questions come up about the costly indirect or side effects of plowing so
many acres for corn ethanol.
If for no other reason, we need to support the sale of ethanol because it
replaces foreign oil. I would challenge all of you to read, read, read. Start
with Energy Victory by Robert Zubrin. Turn three pages on this book
about the Saudis and you will never doubt the need for ethanol and
alternative fuels. Forget that it creates jobs, is good for the environment,
or supports our agriculture economy, or that you hold ethanol to a standard
much higher than gasoline. Forget all that. Read something that sends
chills down your spine about the world we live in and the role foreign oil
now plays.
Every gallon of ethanol produced and consumed are dollars that stay in
America. It reduces our dependence on foreign oil, helps our
environment, saves American’s money with reduced fuel costs and puts
money in the pockets of American farmers instead of Middle Eastern Oil
Czars. Farmers produce more corn each year as needed for food and fuel.
Ethanol is the most successful biofuel we have at our disposal today.
Supporting and using Ethanol today will lead us to the second generation
biofuels evolving in the industry. Cut out Ethanol and the farm economy
collapses. Our mid-western economy is balanced on the success of the
Ethanol industry. Keep it strong and we all succeed. So far the only plants
to my knowledge that have closed are the VeraSun plants as a result of some
poor commodities buying by their personnel. We have an Ethanol plant in
our town Green Plains Renewable Energy that is going strong and
profitable and is working on second generation biofuels. One bad apple
does not spoil the whole bunch. There should be no regulatory caps on
production of Ethanol and standards already set should be kept in place.
Higher blends should be encouraged by our government. It’s the right thing
to do for our country, the environment, and our economy.


W. A. Payne

Table 1


The 9 billion gallons of corn ethanol that were produced last year reduced
gasoline and diesel consumption of the United States by all of 0.8%, when
the fossil fuel that was used to produce the ethanol is taken into account.
Corn ethanol is not an energy program and never was. It is a political
largesse program that has hindered the meaningful development of
alternative fuels. If you are truly serious about developing alternative
transportation fuels, the first thing you would do is eliminate corn ethanol
subsidies and mandates.
Corn is cheap . . . roughly $4 for 56 lbs. . . We should be embarrassed that
56 lbs of corn can be purchased for $4. The Corn Producers worth their tails
off and some people bitch and moan at paying $4 for 56 lbs of corn. . .! We
have so much corn we continue to pay Farmers to NOT grow corn.
It really boils down to who do you want to support (send you money too) Iran
? Bin Laden and his minions? or keep more of our Money and Pride at
home supporting America Farmers, American Producers and American
Consumers. . .
There are two commercial cellulose ethanol plants under construction in
Georgia (Range Fuels) and Florida (Coskata). These use any organic
substance to produce ethanol. The producer cost per gallon of ethanol
should approach $1.00 a gallon! Your Governmental EPA in 2005
produced a study showing E30 (30% ethanol blend) could produce
engine efficiency far superior to plain old gasoline engine efficiency. Yes,
that means higher fuel mileage on E30 than that gasoline. Did you know the
largest oil reserve in the world in the Mid-East, uses massive amounts of
water to get it out of the ground! If you do not think oil (companies)
receive tax breaks that amount to billions of dollars, you are dreaming. This
amount of amount of money far surpasses what ethanol receives. Remove
this and a gallon of gasoline will approach $10 a gallon
Well, ‘‘Voice of Reason’’ we need about 0.3/4s of a gallon of that imported
petroleum to make 1 gallon of corn ethanol. . .not a good deal at all when
you consider additionally that soils and water were used to grow the corn.
Additionally the use of the corn kernels for fuel rather than food distorts
global food markets.
Ethanol has been a blessing for the small independent farmer and all
Americans. The government can now subsidize an industry that would
not be transferred overseas. People have forgotten the gas shortage in the
1970s and the control OPEC had over our nation. I even question the
control the large oil companies have over our nation. Believe me the oil
company executives were receiving their multimillion dollar bonuses in
2007. The ethanol industry will take decades to refine production. POET
Biorefining in Emmetsburg Iowa is now producing ethanol commercially
using corn cobs, but it is a process that needs America’s support to get on its
feet. Ethanol may not be the best long-term alternative fuel source but it is

Are Biofuels Antithetic to Long-Term Sustainability of Soil and Water Resources?

Table 1



an excellent bridging product. We have the pumps and vehicles already in
operation. Also people forget one of the by-products of ethanol production
is distiller grain or high protein animal feed. The energy used to produce
ethanol also produces refined animal feed. Pulling the rug out from under
the growing ethanol business would be a mistake. The agricultural industry
has been working smarter producing more crops with less herbicides and
fertilizer. Ethanol efficiency is increasing to 3 gallons of ethanol per bushel
of corn. Have some faith in our technology. Farmers are continuing to
produce more grain on the same amount of acres using fewer inputs, and
ethanol production is branching out to cellulosic production.

complex, politically and emotionally charged, and filled with uncertainty
and contention (IPCC, 2008—see Key Uncertainties).
Before launching into some of the more contentious issues, however,
some relevant historical points will be made, followed by an overview of

2. Some History
2.1. Ethanol as a fuel
The timeline in Table 2 from the US government’s Energy Information
Administration (EIA, 2009) allows us to extract some relevant historical

Ethanol has been used to power internal combustion engines since the
1800s, including that of Henry Ford’s first automobile. The famous
model T, first produced in 1908, ran on ethanol, gasoline, or a mixture
of the two. In the 1930s, more than 2000 gasoline stations in the US
Midwest sold gasohol, which contained 6–12% ethanol.
 Since the civil war, the economic viability of ethanol has been influenced
by government policy, including taxes and subsidies. The model T came
into production 2 years after the government repealed a $2 per gallon
excise tax on ethanol that had been in place for more than 50 years.
The Energy Tax Act of 1978 amounted to a 40 cents per gallon subsidy
for every gallon of ethanol blended into gasoline; this was later increased
to 50–54 cents. In the 1980s, congress enacted many tax benefits for
ethanol producers and blenders. Government loans and price guaranties
were also offered, and tariffs were imposed on imported ethanol. Despite
all these supports, more than half went out of business by the mid-1980s.


W. A. Payne

Table 2

Timeline of ethanol use in the United States











Samuel Morey developed an engine that ran on ethanol and
German engine inventor Nicholas Otto used ethanol as the fuel
in one of his engines. Otto is best known for his
development of a modern internal combustion engine
(the Otto Cycle) in 1876.
The Union Congress put a $2 per gallon excise tax on ethanol
to help pay for the Civil War. Prior to the Civil War,
ethanol was a major illuminating oil in the United States.
After the tax was imposed, ethanol cost too much to be
used this way.
Henry Ford built his first automobile, the quadricycle, to run
on pure ethanol.
Over 50 years after imposing the tax on ethanol, Congress
removed it, making ethanol an alternative to gasoline as a
motor fuel.
Henry Ford produced the Model T. As a flexible fuel vehicle,
it could run on ethanol, gasoline, or a combination of
the two.
The need for fuel during World War I drove up ethanol
demand to 50–60 million gallons per year.
Gasoline became the motor fuel of choice. Standard Oil began
adding ethanol to gasoline to increase octane and reduce
engine knocking.
Fuel ethanol gained a market in the Midwest. Over 2000
gasoline stations in the Midwest sold gasohol, which was
gasoline blended with between 6% and 12% ethanol.
Ethanol production for fuel use increased, due to a massive
wartime increase in demand for fuel, but most of the
increased demand for ethanol was for nonfuel wartime uses.
Once World War II ended, with reduced need for war
materials and with the low price of fuel, ethanol use as a
fuel was drastically reduced. From the late 1940s until the
late 1970s, virtually no commercial fuel ethanol was
available anywhere in the United States.
The first of many legislative actions to promote ethanol as a
fuel, the Solar Energy Research, Development, and
Demonstration Act led to research and development of
the conversion of cellulose and other organic materials
(including wastes) into useful energy or fuels.
The United States begins to phase out lead in gasoline.
Ethanol becomes more attractive as a possible octane
booster for gasoline. The Environmental Protection


Are Biofuels Antithetic to Long-Term Sustainability of Soil and Water Resources?

Table 2 (continued)





Agency (EPA) issued the initial regulations requiring
reduced levels of lead in gasoline in early 1973. By 1986
no lead was to be allowed in motor gasoline.
The first time gasohol was defined, it was in the Energy Tax
Act of 1978. Gasohol was defined as a blend of gasoline
with at least 10% alcohol by volume, excluding alcohol
made from petroleum, natural gas, or coal. For this
reason, all ethanol to be blended into gasoline is produced
from renewable biomass feedstocks. The Federal excise tax
on gasoline at the time was 4 cents per gallon. This law
amounted to a 40 cents per gallon subsidy for every gallon
of ethanol blended into gasoline.
 Marketing of commercial alcohol-blended fuels began.
Amoco Oil Company began marketing commercial
alcohol-blended fuels, followed by Ashland, Chevron,
Beacon, and Texaco.
 About $1,000,000,000 ($1 billion) eventually went to
biomass-related projects from the Interior and Related
Agencies Appropriation Act.
 First US survey of ethanol production was conducted.
The survey found fewer than 10 ethanol facilities existed,
producing approximately 50 million gallons of ethanol per
year. This was a major increase from the late 1950s until the
late 1970s, when virtually no fuel ethanol was
commercially available.
 Congress enacted a series of tax benefits to ethanol
producers and blenders. These benefits encouraged the
growth of ethanol production.
 The Energy Security Act offered insured loans for small
ethanol producers (less than 1 million gallons per year), up
to $1 million in loan guarantees per project that could cover
up to 90% of construction costs on an ethanol plant, price
guarantees for biomass energy projects, and purchase
agreements for biomass energy used by federal agencies.
 Congress placed an import fee (tariff) on foreign-produced
ethanol. Previously, foreign producers, such as Brazil, were
able to ship less expensive ethanol into the United States.
 The Gasohol Competition Act banned retaliation against
ethanol resellers.
 The Crude Windfall Tax Act extended the ethanolgasoline blend tax credit.
The Surface Transportation Assistance Act increased the
ethanol subsidy to 50 cents per gallon.


W. A. Payne

Table 2


 The number of ethanol plants in the United States peaked

at 163.

 The Tax Reform Act increased the ethanol subsidy to 60

cents per gallon.


 Many ethanol producers went out of business, despite the


 Only 74 of the 163 commercial ethanol plants (45%)




remained operating by the end of 1985, producing 595
million gallons of ethanol for the year.
Ethanol was first used as an oxygenate in gasoline. Denver,
Colorado, mandated oxygenated fuels (i.e., fuels containing
oxygen) for winter use to control carbon monoxide
Other oxygenates added to gasoline included MTBE
(methyl tertiary butyl ether—made from natural gas and
petroleum) and ETBE (ethyl tertiary butyl ether—made
from ethanol and petroleum).
MTBE dominated the market for oxygenates.
Omnibus Budget Reconciliation Act decreased the ethanol
subsidy to 54 cents per gallon of ethanol
Ethanol plants began switching from coal to natural gas for
power generation and adopting other cost-reducing
An expanding market and the high cost of fructose corn
syrup encouraged expansion of wet mill plants that produce
the syrup as a by-product of the ethanol production process.
The Energy Policy Act of 1992 (EPACT) provided for two
additional gasoline blends (7.7% and 5.7% ethanol). It
defined ethanol blends with at least 85% ethanol as
‘‘alternative transportation fuels.’’ It also required
specified car fleets to begin purchasing alternative fuel
vehicles, such as vehicles capable of operating on E-85 (a
blend of 85% ethanol and 15% gasoline). EPACT also
provided tax deductions for purchasing (or converting) a
vehicle that could use an alternative fuel such as E-85 and
for installing equipment to dispense alternative fuels.
The Clean Air Act Amendments mandated the winter-time
use of oxygenated fuels in 39 major carbon monoxide
nonattainment areas (areas where EPA emissions standards
for carbon mioxide had not been met) and required yearround use of oxygenates in nine severe ozone
nonattainment areas in 1995.
MTBE was still the primary oxygenate used in the United


Are Biofuels Antithetic to Long-Term Sustainability of Soil and Water Resources?

Table 2 (continued)


 The excise tax exemption and income tax credits were

extended to ethanol blenders producing ETBE.

 The EPA began requiring the use of reformulated gasoline







year round in metropolitan areas with the most smog.
With a poor corn crop and the doubling of corn prices in the
mid-1990s to $5 a bushel, some States passed subsidies to
help the ethanol industry.
Major US auto manufacturers began mass production of
flexible-fueled vehicle models capable of operating on
E-85, gasoline, or both. Despite their ability to use E-85,
most of these vehicles used gasoline as their only fuel
because of the scarcity of E-85 stations.
The ethanol subsidy was extended through 2007 with a
gradual reduction from 54 cents per gallon to 51 cents
per gallon in 2005.
Some States began to pass bans on MTBE use in motor
gasoline because traces of it were showing up in drinking
water sources, presumably from leaking gasoline storage
tanks. Because ethanol and ETBE are the main
alternatives to MTBE as an oxygenate in gasoline, these
bans increased the need for ethanol as they went into effect.
EPA recommended that MTBE should be phased out
A 1998 law reduced the ethanol subsidy to 53 cents per gallon
starting January 1, 2001.
 US automakers continued to produce large numbers of
E-85-capable vehicles to meet federal regulations that
require a certain percentage of fleet vehicles to be capable
of running on alternative fuels. Over 3 million of these
vehicles were in use.
 At the same time, several States were encouraging fueling
stations to sell E-85.
 With only 169 stations in the United States selling E-85,
most E-85 capable vehicles are still operating on gasoline
instead of E-85.
 A 1998 law reduced the ethanol subsidy to 52 cents per
gallon starting January 1, 2003.
 As of October 2003, a total of 18 States had passed
legislation that would eventually ban MTBE.
 California began switching from MTBE to ethanol to make
reformulated gasoline, resulting in a significant increase in
ethanol demand by midyear, even though the California
MTBE ban did not officially go into effect until 2004.


W. A. Payne

Table 2





The Energy Policy Act of 2005 was responsible for regulations
that ensured gasoline sold in the United States contained
a minimum volume of renewable fuel called the
Renewable Fuels Standard. The regulations aimed to
double the use of renewable fuel, mainly ethanol made
from corn, by 2012.
 The Energy Independence and Security Act of 2007
expanded the Renewable Fuels Standard to require that
36 billion gallons of ethanol and other fuels be blended into
gasoline, diesel, and jet fuel by 2022. The United States
consumed 6.8 billion gallons of ethanol and 0.5 billion
gallons of biodiesel in 2007.
 An Argonne National Laboratory study compared data
dealing with water, electricity, and total energy usage
from 2001 and 2006. During this period, America’s
ethanol industry achieved improvements in efficiency and
resource use while it increased production nearly 300%.
As of March 2008, US ethanol production capacity was at
7.2 billion gallons, with an additional 6.2 billion gallons of
capacity under construction.

From EIA (2009).

A new round of bankruptcies is occurring today (Economist, 2009; NYT,
 The demand for ethanol has long been influenced by the supply and
demand for gasoline. Demand for fuel and therefore ethanol rose dramatically during World War I, and fell drastically after World War II, when
there was reduced need for war materials and plentiful supplies of cheap
gasoline. From the late 1940s until the late 1970s, virtually no commercial
fuel ethanol was available anywhere in the United States. Until 1972,
Americans were accustomed to expanding energy consumption with
little concerns about supply or sharp price increases (Hakes, 1998).
 When gasoline prices have become high due to strong demand or
constricted supply, government policies have strongly supported the
development and production of ethanol. The legislative actions to promote fuel ethanol in 1974, for example, were in response to turmoil in
1973, which began with electricity brown outs and rapidly rising prices
for fuel, food, and other necessities. Then, an oil embargo was imposed
in October 1973 on the United States by members of the Organization of
Arab Petroleum Exporting Countries, cutting further into the supply
of oil and elevating prices to levels previously thought impossible

Are Biofuels Antithetic to Long-Term Sustainability of Soil and Water Resources?


(Hakes, 1998). About $1 billion was invested then by the US government
into conversion technologies.
 Over the past several years, remarkable gains have been made in both
efficiency of conversion processes and production capacity.

2.2. Soil and oil
Soon after the energy crisis, the soil physicist C.H.M. Bavel (1977) noted
that the United States was importing $36 billion worth of oil per year and
exporting $23 billion of agricultural products, mostly grain and soybeans.
The bounty of our farms, he argued, was supporting and extending the
profligacy of our energy consumption. He also wondered whether the
production levels at the time of wheat, corn, and soybean could be maintained, particularly in view of very high rates of soil erosion. Van Bavel
(1977) cited a 1971 analysis suggesting that unrestricted land use, including
expansion of agriculture into marginal lands, could lead to a national soil loss
rate of 20 metric tons per ha, which at the time was seen as twice as high as
the maximum tolerable rate. In effect, he argued, we were exporting several tons
of soil to the Gulf of Mexico for every ton of grain exported to offset our energy
demand. This amounted to a bad trade of soil for oil.

2.3. Charting our future in the past
In the late 1980s, soon after US legislation began mandating the addition of
oxygenates in gasoline, which in effect increased demand for ethanol, then
ASA president E.C.A. Runge (1990) pointed out a fundamental dilemma
that USDA’s supply control programs and the potential of ethanol from
crops presented for agricultural scientists:
We are supposed to develop the technology that keeps US farmers competitive, but we aren’t supposed to create the technology that creates a
surplus for the secretary of agriculture to deal with. Obviously, you can’t
have one without the other. It is this surplus agricultural production which has
negatively impacted agriculture and agronomists, in particular, for the past
decade. Can we create a demand for this excess agricultural production?

Even then, there were detractors of mixing ethanol into fuels. Runge
(1990) cited one author who suggested that ‘‘gasohol’’ would not be
economical until crude oil reached $60 per barrel. Runge (1990) argued
that whether ethanol production was economically viable depended on the
comparison made and the technology assumed, and that if the cost of
ethanol production was compared with the cost of USDA’s supply control
programs, the ethanol alternative was very economical.
He reasoned further that, because a very large percentage of our crops
are grown under rainfed conditions, we cannot predict agricultural supply.


W. A. Payne

Therefore, government policy must opt for more than enough crop production during average or normal weather years to see us through drought
years, when production is below average. That is, excess crop production is
the norm rather than the exception, and supply control policies would
always be out of phase with need if weather is a variable.
Runge (1990) proposed that ethanol be used as a ‘‘sink’’ for any excess
crop production rather than utilizing acreage reduction programs, export
enhancement programs, etc., to control supply. He calculated that we could
have saved nearly a billion dollars by converting the corn that we were
exporting in 1987 to ethanol instead. Other positive aspects of such a policy
included increased gross domestic product, rural development, improved air
quality, CO2 reduction, and revenue enhancement at the local, state, and
federal levels.
But Runge also stressed that we must have a US agriculture that is not
only enhanced by science but in harmony with environmental and human
values. He called for policies that would create a favorable climate for
investors and companies to design plants to use this excess production,
pointing out that there would be little investment if there were no assured
supply or unstable prices of the raw materials needed to run their plants.
Even 20 years ago, ethanol production technology was changing rapidly,
leading Runge (1990) to predict that the positive energy contribution of
ethanol produced would increase dramatically in the next few years with
state-of-the-art plants.
Runge’s (1990) goal of sustainably utilizing our agricultural enterprise to
its maximum included a vision of cooperation between US agriculture, the
energy industry, the motor fuels industry, and environmentalists to solve
our problems of air quality, greenhouse gas emission, energy imports, and
agricultural and rural development problems. He believed that the beneficiaries of this cooperative effort would include US agriculture, and agricultural scientists who provide progrowth technologies for US agriculture.
But the main beneficiaries would be US citizens because of a revitalized
rural economy, increased GDP, and improved air quality.

3. An Overview of Biofuels1
Biofuels contain energy derived from biomass produced through the
capture of solar energy through photosynthesis. A wide range of biomass
can be used to produce several forms of biofuel. Sources of biomass include
waste from food, fiber and wood industrial processes, and any number of

Much of this summary relies upon the thorough review by FAO (2008).

Are Biofuels Antithetic to Long-Term Sustainability of Soil and Water Resources?


agricultural and forestry products. Biomass can be used to generate electricity, heat, power, fuel, and other forms of bioenergy. Because the primary
source of energy is solar (even if animal products are used), biofuels are seen
by many as a form of renewable energy.
Biofuels can be in the form of solid, liquid, or gas. They can also be
classified as primary (i.e., unprocessed) or secondary (i.e., processed).
Primary biofuels are directly combusted, usually for cooking, heating, or
electricity production needs in industry.2 Secondary biofuels can be solid
(charcoal or wood pellets), liquid (ethanol, biodiesel, or bio-oil), or gaseous
(biogas or hydrogen). Secondary biofuels can be used for a wider range of
applications, including transport and high-temperature industrial processes.
Of course, the strongest growth in recent years has been in secondary liquid
biofuels for transport, which are mostly produced using agricultural and
food commodities as feedstocks. The most important of these are ethanol
and biodiesel (FAO, 2008).

3.1. Ethanol
Ethanol produced for biofuel today is based on feedstocks containing either
sugar or starch. Common sugar crops used as feedstocks include sugarcane,
sugar beet, and sweet sorghum. Feedstocks containing starch or cellulose,
which can be converted to sugar, can also be used to produce ethanol. The
most common among these include corn, wheat, and cassava. Especially in
Brazil and other tropical countries, sugarcane is the most widely used
feedstock. In nontropical countries, the starch component of cereals is
more commonly used.
Ethanol can be blended with gasoline or burned in its pure form in
internal combustion engines. One liter of ethanol contains approximately
66% of the energy of 1 l of gasoline, but it has a higher octane level. When
mixed in gasoline, it therefore improves performance and fuel combustion
in vehicles, thereby reducing emissions of carbon monoxide, unburned
hydrocarbons and carcinogens. However, the combustion of ethanol also
causes a heightened reaction with nitrogen in the atmosphere, which can
result in a marginal increase in nitrogen oxide gases. Ethanol also only
contains small amounts of sulfur. When mixed with gasoline, ethanol
therefore reduces fuel sulfur content and emissions of sulfur oxide, which
contributes to acid rain and is a carcinogen.


One recent article (Campbell et al., 2009) suggests that converting biomass to electricity to power batterypowered vehicles is much more land-use efficient, transport-efficient, and emission-offset efficient than


W. A. Payne

3.2. Biodiesel
Biodiesel is produced by combining vegetable oil or animal fat with an
alcohol and a catalyst through transesterification. Oil for biodiesel production can be extracted from most oilseed crops. The most popular sources are
rapeseed in Europe and soybean in Brazil and the United States. In tropical
and subtropical countries, biodiesel is produced from palm, coconut, and
jatropha. Small amounts of animal fat, from fish- and animal-processing
operations are also used. The production process typically yields additional
by-products, such as crushed bean ‘‘cake’’ that can be used as an animal
feed, and glycerine. Because biodiesel production can be based on a wide
range of oils, the resulting biofuels have a greater range of viscosity and
combustibility than ethanol.
Biodiesel can be blended with traditional diesel fuel or burned in pure
form in compression ignition engines. Its energy content is 88–95% of
regular diesel, but it improves lubricity and raises the cetane value, making
its fuel economy generally comparable to that of diesel. Its higher oxygen
content aids in fuel combustion, thereby reducing emissions of particulate
air pollutants, carbon monoxide and hydrocarbons. Similar to ethanol,
biodiesel also contains only traces of sulfur.
Straight vegetable oil is another potential fuel for diesel engines that can
be produced from a variety of sources, including oilseed crops, cooking oil,
and animal fat.

3.3. Cellulosic ethanol
The starch and sugar components of crops represent only a small fraction of
total plant mass, which is mostly composed of cellulose, hemicellulose, and
lignin. Cellulose and hemicellulose can be also converted into ethanol after
they are first converted into sugar, but the process is more difficult. A second
generation of technology—termed recently the ‘‘holy grail’’ of biofuels
(CSM, 2009)—promises to make it economically possible to use cellulosic
biomass for ethanol production. There is currently much ongoing research
and even a few pilot plants devoted to converting cellulosic biomass into
ethanol, but little commercial-scale production. As cellulosic biomass is the
most abundant biological material on earth, the successful development of
commercially viable second-generation cellulose-based biofuels could significantly expand the volume and variety of feedstocks that can be used for
production. Cellulosic wastes, including waste products from agriculture
(straw, stalks, leaves) and forestry, wastes generated from processing (nut
shells, sugarcane bagasse, sawdust) and organic parts of municipal waste,
could all be potential sources.
Potential crops that could serve as a feedstock source for cellulosic
ethanol include short-rotation woody crops, fast-growing trees, and grassy

Are Biofuels Antithetic to Long-Term Sustainability of Soil and Water Resources?


species such as switchgrass. Since the entire crop can be used, an ideal plant
species would rapidly produce large amounts of biomass. The use of cellulosic biomass would theoretically permit the production of more fuel per
hectare of land. Furthermore, some species are adapted to poor degraded
soils, which in theory could provide avenues not only for land rehabilitation
but avoid competition for land with food crops.3

3.4. Biofuel feedstocks and conversion to biofuel
Because nearly any source of biomass can be used for biofuel, there is a wide
array of potential biofuel feedstocks across the world. Currently, for
instance, by-products of forest industries are used to produce fuelwood
and charcoal, while those of pulp mills provide a major fuel source for
bioelectricity generation in many countries. A number of crop and forest
residues are also used to produce heat and power.
But the largest growth in recent years has been in ethanol and diesel
biofuels for transport using agricultural crops as feedstocks. In 2007, $85%
of the global production of liquid biofuels was in the form of ethanol
(Table 3). Despite the fact that almost any biomass source can be used,
most of the world’s ethanol production comes from sugarcane or corn
(FAO, 2008). In Brazil, the bulk of ethanol is produced from sugarcane,
while in the United States it is produced from corn. Other significant
Table 3

2007 ethanol and biodiesel production of the world and selected countries


Ethanol (millions of l)

Biodiesel (millions of l)

United States of America
European Union



From FAO (2008).


Cellulosic ethanol from woody crops, fast-growing trees, and grasses is not at all without its strong critics.
See, for example, the long and heavily referenced report by the environmental group Global Forest
Coalition (2007).


W. A. Payne

feedstocks include cassava, rice, sugar beet, and wheat. The two largest
ethanol producers, Brazil and the United States, made up nearly 90% of total
production in 2007, with major production occurring also in Canada,
China, the EU (mostly France and Germany), and India.
For biodiesel, the most popular feedstocks are rapeseed in the European
Union (EU), and soybean in the United States and Brazil. Palm, coconut,
and castor oils are used in tropical and subtropical countries as biodiesel
feedstocks, and the use of jatropha has been rapidly increasing. Biodiesel
production was principally concentrated in the EU, with much smaller
production in the United States. Other significant biodiesel producers
include Brazil, China, India, Indonesia, and Malaysia.
Because of potentially rapid changes in prices, government policies,
land-use patterns, and public perceptions on food security, subsidies, the
environment, etc., it is difficult to know how the absolute and relative
trends shown in Table 3 for global biofuel production will evolve among
countries—changes have been occurring almost weekly (FAO, 2008).
Crop yield data in Table 4, taken from FAO (2008), are presented firstly
to illustrate what agronomists already know very well—crops vary widely in
terms of yield per hectare across regions and production systems. But agronomists also know better than any how crop yields change from place to place
and year to year due to a myriad of processes that underlie the complexity of
our science. Even the most tranquil agronomist must feel compelled to
question single static yield values given for, say, corn and soybean for the
entire United States. Agronomists also know that almost any measure of crop
quality, which for biofuels includes sugar, starch, oil, and cellulose contents,
also changes with complex environmental and genetic processes.
Therefore, without even entering into the chemical engineering aspects
of conversion efficiencies listed in Table 4, agronomists know that these
efficiencies cannot be seen as fixed or static. Agronomists, plant breeders,
and other agricultural scientists should critically view such static values not
only in terms of how they represent current yields, but how well they
represent potential yields that new technologies could bring about. This is
part of the centuries-old Malthusian debate (Evans, 1998), which Runge
(1990) framed within the context of biofuel and our capacity to sustainably
increase agronomic production.
This is not meant to criticize the illustrative overview given by FAO
(2008). It is rather to illustrate just one source of uncertainty and disagreement from one of many complex scientific disciplines involved in the
biofuel debate.
Further uncertainties come into play when considering all the energy
requirements needed to produce a crop and convert it into biofuel, as
illustrated by the range of energy balance calculations shown in Fig. 1.
A fossil energy balance of 1.0 implies as much energy is needed to produce
1 l of biofuel as it contains. An energy balance of 2.0 means that 1 l contains


Are Biofuels Antithetic to Long-Term Sustainability of Soil and Water Resources?

Table 4 Static estimates of crop yield, conversion efficiencies, and biofuel yields for
the world and selected countries


Oil palm
Oil palm













States of
States of













From FAO (2008).

twice the amount required to produce it. The FAO (2008) report used
calculations from the Worldwatch Institute (2006), an organization which
not all taking part in the lively debate captured in Table 1 would see as
neutral. Nonetheless, the figure serves to illustrate that there exist wide
variations in energy balances estimated for different feedstocks and fuels.
Some of these considerations are mentioned in the contrasting studies of
Pimentel and Patzek (2005) and Liska et al. (2008). A simplified list of factors
to consider includes the energy associated with land preparation, growing
and harvesting the crop, processing the feedstock into biofuel, transport of
both feedstock and biofuel, and storage, distribution, and retail of biofuel.
For many reasons, including choice of data sources, energy terms that are
excluded or included, and methodologies used, energy balance of biofuel is
a very contentious subject (FAO, 2008).

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