[USDA Global Conference on Agricultural Biofuels: Research and
Economics]{.smallcaps}

**Sustainable Production**

**and Environmental**

**Considerations**

**Making Crop Residues a Sustainable Feedstock for Biofuel Production**

Wally Wilhelm

Plant Physiologist, Agroecosystems Management Research Unit

USDA-ARS, Lincoln, Nebraska

[www.ars.usda.gov](http://www.ars.usda.gov/)

The US has embarked on the challenging goal of replacing much of its
current fossil-based fuels with renewable fuels (as much as replacing
30% of current gasoline consumption with renewable fuels by 2030. The
nation's agriculture and forestry systems will be tested to produce, in
a sustainable manner, the billion tons of feedstock predicted to be
needed to achieve this goal. Environmental sustainability implies that
additional production can be generated without negative impacts on
output of traditional products (food, feed, and fiber) or environmental
quality while meeting the new demands. Removing crop biomass (stover or
residue) from the land will reduce soil carbon content, the soil
fraction responsible for many favorable soil properties,
[if]{.underline} other crop and soil management practices are not
changed simultaneously. An extensive effort will be needed to develop
crops and advanced cropping systems that greatly expand biomass
production and provide a sustainable supply of feedstock while
continuing to provide traditional output and the carbon to sustain the
soil ecosystem.

[Wally Wilhelm]{.smallcaps}

[Biography]{.smallcaps}

Wally Wilhelm is a research plant physiologist with the USDA-ARS
Agroecosystems Management Research Unit and adjunct professor of
agronomy and horticulture at the University of Nebraska, Lincoln, NE. He
leads the ARS Renewable Energy Assessment Project (REAP), a
multi-location effort to develop tools and cropping practices that
maximize sustainable harvest of biomass as bioenergy and bioproduct
feedstocks. He has worked to help the cellulosic ethanol industry
understand that crop residues are not wastes of grain production and
that residues play a vital role in maintaining soil functions and
preserving the capacity of agricultural lands to produce food, feed, and
fiber when remained to the soil.

**[Sustainability of Biomass Production in Context]{.smallcaps}**

David I. Bransby

Professor, Energy Crops and Bioenergy

Department of Agronomy and Soils

Auburn University, Alabama

[www.auburn.edu](http://www.auburn.edu/)

Production of cellulosic biomass, for conversion to biofuels especially,
has multiple global benefits. Among the most important of these is
increased global energy security, reduced greenhouse gas emissions by
replacement of fossil fuels and carbon sequestration, with an associated
reduction in the risk of global climate change, and stimulation of rural
economies around the world. There are many other important but somewhat
less significant environmental benefits from biomass crops, such as less
soil erosion if a perennial is used to replace an annual, improvement of
soil quality, better water conservation, improved wildlife habitat, etc.
While it is recognized that environmental sustainability is an essential
element of new cropping systems, the need for economic sustainability in
order to reap the environmental benefits listed above should not be
overlooked. In this regard, yield in biomass dry matter per unit area
per year and the price that a processing plant can afford to pay for
biomass are probably the most important determining factors. The latter
will depend largely on the biofuel yield per unit weight of biomass.
Consequently, in relation to crop production, strategies to increase
yield per acre should receive high research priority, while increasing
biofuel yield per unit of biomass should receive high priority in
conversion technology research.

All possible benefits from cellulosic biomass can not be maximized with
a single cropping system, and environmental and economic sustainability
often pull in different directions. Therefore, compromises will often
need to be made to ensure sustainability and to optimize environmental
benefits in any particular situation, but great care should be taken to
avoid strategies that focus on achieving relatively minor environmental
goals at the expense of losing major benefits. In order to do this it is
vitally important to prioritize environmental benefits from biomass
cropping systems, and subsequently to design research aimed at
maximizing these within the constraints of economic sustainability.

[David Bransby]{.smallcaps}

[Biography]{.smallcaps}

**Dr. David Bransby** is a Professor of Energy Crops and Bioenergy in
the Department of Agronomy and Soils at Auburn University. He has over
30 years of experience in agronomic research, and has spent 20 years
specializing in the production and processing of energy crops. Dr.
Bransby is a national authority in this field, and has an international
reputation for his work. He has over 300 technical publications, serves
on the editorial boards of two international bioenergy journals, and
consults for several private bioenergy companies. In September of 2006
Dr. Bransby was asked to brief Governor Riley of Alabama and President
Bush on the status of the emerging biofuels industry. In February 2007
he was invited to the White House to advise President Bush, Secretary of
Energy Sam Bodman and senior White House officials on the feasibility of
large scale cellulosic biofuel production in the United States over the
next 10 years.

**[Ethanol Production and Water Quality]{.smallcaps}**

Thomas W. Simpson, Ph.D.

. Department of Environmental Science and Technology,

University of Maryland, College Park, MD USA 20742

[www.umd.edu](http://www.umd.edu/)

Renewable transportation fuel production, particularly ethanol, is
expanding rapidly to reduce reliance on fossil fuels while also reducing
associated air pollution. In the United States, most ethanol is produced
from grains, primarily corn. Grain-based ethanol may provide a
competitively priced transportation fuel but substantial opportunity
exists for unintended environmental impacts, particularly related to
water quality. Cellulosic ethanol from perennial grass feedstocks, such
as switchgrass, has the potential to provide renewable fuels while also
improving soil, water and air quality. However, substantial technology
and infrastructure impairments exist to competitive commercialization of
grass based cellulosic ethanol. Expanded grain-based ethanol will
increase and intensify corn production in the U.S., as has occurred in
2007. Corn is inherently inefficient in using nutrients, even under
reasonable management and loses more nitrogen (N) and phosphorus (P) per
unit land area to water than other agricultural commodity crops. Dried
distiller's grains (DDG) remaining after ethanol production are being
used as animal feed and will increase manure P content and may increase
N content. Ethanol has much potential as a transportation fuel, but
dependence on grain, primarily corn, in the U.S. as the dominant
feedstock for ethanol has water quality and quantity, feed and food
implications. To address water quality concerns, conservation efforts
must be increased as corn acreage and intensity of production increases
just to minimize the increase in nutrient pollution. Development of
commercially viable cellulosic ethanol needs to be accelerated to allow
for sustainable expansion of ethanol production in the U.S. without
further degradation of water resources. Policies, programs and science
need to consider water quality as well as other environmental, social
and economic impacts of the major expansion of ethanol production
underway in the U.S. and around the world if it is to be successful and
sustainable.

[Thomas W. Simpson]{.smallcaps}

[Biography]{.smallcaps}

Dr. Tom Simpson is Professor and Coordinator of Chesapeake Bay Programs
in the Department of Environmental Science and Technology at the
University of Maryland. He has a BS from Virginia Tech and an MS and
Ph.D. from Penn State, all in Soil Science. From 1980 to 1992, he was
Professor of Soil-Environmental Quality at Virginia Tech, focusing on
organic waste management and agricultural water quality issues. Tom's
current work focuses on Best Management Practice efficiency,
conservation innovation, and ethanol and water quality.

Dr. Simpson coordinates science-policy activities regarding nonpoint
source pollution in the Chesapeake Bay watershed. He chairs the Bay
Program's Nutrient Subcommittee, leads the Mid-Atlantic Land Grant
University Water Quality Program and is on the USDA-Land Grant
University Committee for Shared Leadership on Water Quality. He has
served on numerous panels and boards and is currently on the EPA Hypoxia
Advisory Panel for the Gulf of Mexico and Mississippi River Basin. He
also works on water quality issues in the Danube/Black Sea Basin and
Israeli-Palestinian transboundary waters. His primary emphasis is on
innovation in water quality programs, practices and policies, and
integration of science into water policy.

**[Biofuels from Perennial Prairie Plant Polycultures and the Ecosystem
Services They Provide]{.smallcaps}**

Dr. Jason Hill

Research Associate

University of Minnesota

[www.umn.edu](http://www.umn.edu/)

Recent experiments have demonstrated that in grassland ecosystems
increasing plant diversity not only provides greater and more stable
biomass yields but also results in higher rates of atmospheric carbon
sequestration in soils. Highly diverse mixtures of native prairie plant
species, including grasses, legumes, and other forbs, grown with low
agrichemical inputs offer an abundant bioenergy source with multiple
environmental benefits including accumulation of soil organic matter,
nutrient enrichment from nitrogen fixation, erosion control, wildlife
habitat, and resistance to diseases, pests and invasive species. As
achieving greater energy independence from fossil fuels will require
expanding and diversifying renewable energy feedstocks, biofuels derived
from prairie biomass are ideally suited to be produced from marginal and
degraded lands, thereby sparing the most fertile farmlands to be used to
satisfy increasing demand for food.

[Jason Hill]{.smallcaps}

[Biography]{.smallcaps}

Jason Hill is a research associate in the Department of Applied
Economics and the Department of Ecology, Evolution, and Behavior at the
University of Minnesota. There he is part of an interdisciplinary team
conducting integrative analyses of the technological, environmental,
economic, and social aspects of sustainable bioenergy production from
current and next-generation feedstocks such as diverse prairie biomass.
Previously, he was an assistant professor of biology at St. Olaf
College. Hill received his A.B. in biology from Harvard College and his
Ph.D. in plant biological sciences from the University of Minnesota.

**[Biofuel Climatic Risks Zoning in Brazil]{.smallcaps}**

Eduardo Delgado Assad, Phd

Agroclimatologist

Embrapa - Brazil

www.cnptia.embrapa.br

According to Brazilian Agriculture Ministry, agricultural losses in
Brazil until 1995 were mainly due to drought during the reproductive
phase (60% of all cases) and very humid periods during harvesting (30%)
caused by the unknown of the rainfall distribution that led to the wrong
habit of planting immediately after the first spring rainfall. To reduce
these climatic risks, the Ministry of Agriculture and the EMBRAPA are
coordinating since 1996 the Agricultural Risks climatic Zoning Program
destined to define planting calendars to guarantee at least 80% of
certainty of having an adequate water supply for rice, beans, corn,
soybean, wheat, cotton, coffee, apple, manioc, and crops without
artificial irrigation. The planting periods were defined through the
simulation of a climatic water balance that gives an index of water
supply using historical rainfall data, minimum 20 years daily rain data
base, potential evapotranspiration, physiological characteristics of
each crop and water retention by the soil, in many different types of
Brazil soils.

The Agricultural Zoning is already concluded from the 21 States of
Brazil that correspond together to more than 90% of the Brazilian
agricultural production. The governmental financial agents are using the
planting calendars as official support to decide about the agricultural
financing that comprehends up to US\$ 9 billions per year.

Actually, this program recommends the planting calendars in more than
5300 counties, with 13 different crops, and identified 25 different rain
zones in the country. In the last two years the priority was defined to
finalize the studies of climatic risk zoning to the principal biofuel
cultures like soybean, cotton, sunflower, Castor seed and with
characteristics of ethanol from sugar cane. The objective of this work
is to present the bases of climatic risk zoning of Brazil and the space
extension for the principal energetic cultures. The proposal is to
identify what, when and where to plant the biofuel products.

[Eduardo Delgado Assad, Phd]{.smallcaps}

[Biography]{.smallcaps}

Dr. Assad is an Agroclimatologist for Embrapa -- Brazil. He graduated in
Rural Engineering in 1979 from Viçosa University-Brazil. He received his
MsC in Remote Sensing and Agrometeorology from the University of
Montpellier, France in 1983 and his Ph.D. in Remote Sensing and
Agrometeorology at the same university in 1987. He completed a Pos Phd
in Remote Sensing and Agrometeorology at the University of Campinas,
Brazil in 2001. He has been a researcher at Embrapa since 1987 in
Natural Resoucers and Agroclimatology, and is currently the National
Coordinator of Climatic Risk Zoning in Brazil and the Head of team of
Embrapa Technology of Information and Agriculture Informatics.