Comparing Energy Use in Conventional and Organic Cropping Systems

1. Comparing Energy Use
in Conventional and
ATTRA Organic Cropping Systems
A Publication of ATTRA—National Sustainable Agriculture Information Service • 1-800-346-9140 • www.attra.ncat.org
By Holly Hill Both conventional and organic agriculture depend Energy use in agriculture
NCAT Program on fossil fuel and solar energy. The amount of
Specialist Energy consumption can vary significantly
energy used on farms varies depending on the
© 2009 NCAT between conventional and organic produc-
size and geographic location of the farm, as well
tion systems when accounting for direct
as the types of products and processes used on
the farm. It has been estimated that since 1992,
energy inputs as well as indirect energy
Contents involved in manufacturing, shipping and
direct energy expenses from fuel and electricity
Energy use in
averaged around 7 percent of the average U.S. applying pesticides and nitrogen-based
agriculture ........................ 1
farm’s total operating costs. Incorporating indi- fertilizers. Because organic agriculture
Comparison
considerations ................. 1 rect expenses from such things as fertilizers and reduces the amount of indirect energy
Studies................................ 2 pesticides increases this average to 15 percent of inputs, it is often assumed that organic
Rodale Institute ..................2 total operating costs (1). agriculture is less energy intensive than
University of California ....2 conventional agriculture. However, this is
University of Manitoba ....3 not always the case.
Washington State
University ................................3 Practices such as irrigation, heavy machin-
Switzerland Research ery use and heated greenhouses consume
Institute of Organic large amounts of energy. These practices
Agriculture ...........................3
are utilized by both organic and conven-
Agricultural University
of Norway .............................4 tional operations. Energy use associated
Department for with processing, packaging, storage and
Environment, Food and
Rural Affairs .................. 5 & 6
distribution must also be taken into
Soil Association responds
account. Several studies have attempted to
to the Manchester compare the yield differences, energy inputs
Business School report ....6
and environmental effects associated with
University College Dublin...7
conventional and organic cropping systems.
United Nations Food and
Agriculture Organization ....7
What follows is a summary of some of the
results of these studies.
Conclusion ........................ 8
References ........................ 8
Further resources ........... 8 Comparison considerations
Several factors must be considered when
comparing the energy intensiveness of
conventional and organic systems. One
ATTRA—National Sustainable
Agriculture Information Service significant challenge is representing a
(www.ncat.attra.org) is managed typical conventional or organic system.
by the National Center for Appro-
priate Technology (NCAT) and is Farming practices vary widely depending on
funded under a grant from the
United States Department of
the location and size of the farm, the type
Agriculture’s Rural Business- of crop produced and individual farmer
Horticulturist Eric Brennan records data on weed
Cooperative Service. Visit the
decisions. Conventional farming practices
NCAT Web site (www.ncat.org/ seedling growth between rows of a young cover crop
sarc_current.php) for at USDA’s 17-acre certified organic research plot in range from high-input intensive systems to
more information on
our sustainable agri- Salinas, California. Photo by Scott Bauer, courtesy near-organic systems. Similarly, organic
culture projects. USDA ARS. systems, although adhering to a set of

2. standards, differ in implementation. Some three-year rotation of hairy vetch/corn and
organic farms are highly sustainable rye/soybeans and wheat. The two organic
ecological systems, but some are large-scale systems receive no chemical fertilizers or
monocropping or mass livestock operations pesticides.
that operate like conventional farms, with
David Pimentel, a Cornell University profes-
the exception of not using synthetic pesti-
cides, fertilizers and veterinary drugs (2). sor of ecology and agriculture, was the lead
author of this study and concluded that “fos-
Other factors that affect a reliable compari- sil energy inputs in organic corn production
son of conventional and organic agricultural were 31 percent lower than conventional corn
systems include: production, and the energy inputs for organic
• Limited research in the United States soybean production were 17 percent lower
than conventional soybean production.” (3)
Many of the studies included in this www.organic-center.org/reportfiles/ENERGY_
publication are international in scope. SSR.pdf
This is due to a lack of comparison
trials in the United States. Energy utilization Sustainable Agriculture
comparisons are difficult among countries Farming Systems Project:
Related ATTRA because differences in climatic conditions
Publications and crop rotations affect inputs and yields. University of California, Davis
Farm Energy International organic certification standards A team of researchers, farmers and farm
Calculators: Tools also may differ somewhat from U.S. advisors established the Sustainable Agri-
for saving money Department of Agriculture standards. culture Farming Systems project (SAFS)
on the farm at the University of California, Davis, in
• Structure of comparison
Efficient 1988 to study the transition from conven-
Agricultural Buildings: One issue that affects reliable compar- tional farming systems to low-input organic
An Overview ison is how to account for the potential systems. The project has compared four
yield differences between systems. Should systems: organic, low-input, conventional
Energy Savings Tips
for Irrigators
energy consumption be measured per unit four-year rotations and a conventional two-
of land area, per unit of economic activity year rotation. Cash crops in the four-year
Renewable or per unit of produce? rotations include processing tomatoes,
Energy Opportunities
on the Farm • Boundaries of comparison saff lower, dry beans, wheat and corn.
The two-year rotation includes tomatoes
Federal Resources Another issue is how to account for embed-
and wheat.
for Sustainable ded and indirect energy consumption. How
Farming and Ranching do comparisons incorporate pre- and post- The team found that the low-input system
Federal Conservation production energy inputs? was most energy efficient and that crop
Resources yields were comparable among the differ-
ent systems. Tomato and corn yields in the
Food Miles: Studies organic system were a little lower than in
Background and
Marketing Rodale Institute the low-input and conventional systems,
Farming Systems Trial mainly from nitrogen limitations. Differ-
ences in yields were much greater between
The widely referenced 27-year Rodale Insti- years than between systems.
tute Farming Systems Trial (FST) is the
longest-running side-by-side comparison of The SAFS team concluded that “the organic
organic and conventional corn and soybean system is less efficient than the low-input
production systems in the United States. system because of the great distance that
The study compares a conventional farm many organic fertilizers (such as dried sea-
that uses recommended fertilizer and pes- weed) are shipped before arriving at the
ticide applications with an organic animal- field, and because of energy requirements
based farm where manure is applied and for mechanical weed control.” (4)
an organic legume-based farm that uses a http://wsare.usu.edu/pro/pr2001/SW99-008.pdf
Page 2 ATTRA Comparing Energy Use in Conventional and Organic Cropping Systems

3. University of Manitoba Glenlea environmental and economic sustainability,
Study of long-term rotations this study rated the organic system first, the
integrated system second and the conven-
The Glenlea Study began in 1992 with
tional system last.
the objective of creating a long-term compari-
son of the biological, environmental and eco- Researchers measured several indicators
nomic impacts associated with conventional, of sustainability, including energy effi-
low-input and organic cropping systems. ciency. Energy accounting was divided into
Reseachers analyzed energy use between inputs such as labor, fuel, fertilizers and
1992 and 2003. The experiment included so on; output, or yield; and output-to-input
two four-year crop rotations of either wheat- ratios, or a measure of energy efficiency.
pea-wheat-fl ax (WPWF) or wheat-alfalfa- Cumulative energy inputs and outputs for
alfalfa-fl ax (WAAF); and two crop input the six-year study period were lower for the
combinations of either a fertilizer- and organic system than for the conventional
herbicide-added (F+H+) conventional and integrated systems. The output-to-input
system or a no-inputs organic system (F-H-). ratio for the organic system during the
See Table 1 for more information. six-year study period, however, was 7 per-
This study found that eliminating fertilizer and cent greater than that for the conventional
pesticide inputs in the organic system resulted system and 5 percent greater than that for
in energy-use reductions. Also notable is the the integrated system, making the organic
potential of perennial forage legume crops, in system the most energy efficient (5).
this case alfalfa, in reducing energy use.
Learn more about the study online at www.
For a full discussion of results, along with crop- nature.com/nature/journal/v410/n6831/full/
ping system yield information, weed dynamics, 410926a0.html.
soil nutrient status and economic analysis, see
the Glenlea Study Web site at www.umanitoba. Switzerland Research Institute
ca/faculties/afs/plant_science/glenlea/
glenlearesresults.html. of Organic Agriculture:
Soil Fertility and Biodiversity
Washington State University: in Organic Farming
Sustainability of three apple The DOK (bio-Dynamic, bio-Organic, and
production systems Konventional) long-term field experiment was
In this study, researchers at Washington State developed in 1978 in Therwil, Switzerland.
University investigated the sustainability The experiment investigated differences in
of organic, conventional and integrated crop yield, soil biology, environmental health
apple production systems in Washing- and product quality among organic, biody-
ton State from 1994 to 1999. In terms of namic and conventional agriculture methods.
Table 1. Total rotational energy consumption (MJ/ha)* in the Glenlea long-term cropping systems study, 1992-2003
Total
Seed energy Fuel and Machinery Pesticide Fertilizer
Rotation Inputs energy
lube energy energy energy energy
consumption
WPWF F+H+ 68,498 7,902 16,133 2,367 7,116 34,980
WPWF F-H- 24,233 7,902 14,229 2,102 0 0
WAAF F+H+ 49,255 3,657 18,184 2,515 3,499 21,400
WAAF F-H- 22,181 3,657 16,213 2,311 0 0
WPWF = wheat-pea-wheat-flax; WAAF = wheat-alfalfa-alfalfa-flax *MJ/ha=megajoules/hectare
www.attra.ncat.org ATTRA Page 3

4. Between 1978 and 1998, this Swiss exper- www.mindfully.org/Farm/Organic-Farming-
iment evaluated energy use for potatoes, Fertility-Biodiversity31may02.htm.
winter wheat, beetroots, barley and grass-
clover under four different cropping systems:
Agricultural University of
1) BIODYN, or biodynamic; Norway: Energy Utilization in
2) BIOORG, or bioorganic;
Crop and Dairy Production in
Organic and Conventional
3) CONFYM, or conventional using mineral Livestock Production Systems
fertilizer plus farmyard manure; and
This study used data recorded between
4) CONMIN, or conventional using mineral 1990 and 1992 from 14 organic and 17
fertilizer exclusively. conventional farms affiliated with the
Nor weg ian Inst itute of Ag r iculture
This study found that the organic farming
Science. All of the farms studied had dairy
systems used from 20 to 56 percent less production combined with grain produc-
energy to produce a crop unit, measured in tion, except two of the organic farms that
metric tons. Per land area this difference had beef cattle as the main endeavor.
was from 36 to 53 percent. See Table 2 for
additional information (6). Energy use was analyzed for small grains,
grass clover and fodder beets in three soil
For more information on this experi- types. Energy price was determined by the
ment, visit http://orgprints.org/7682/01/ total number of energy inputs in megajoules
Fliessbach_ et_ al_ DOK-trial.doc a nd divided by the total yield output in kilograms.
Table 2. Energy input per unit land area (GJ ha–1) in the second crop rotation (n = 3)
Crop BIODYN BIOORG CONFYM CONMIN
Potatoes 26.39 28.42 39.85 40.69
Winter wheat 1 12.52 11.56 18.88 19.74
Beetroots 16.31 15.14 28.53 31.56
Winter wheat 2 10.31 9.79 20.49 21.81
Barley 8.82 9.62 16.29 15.78
Grass-clover 6.43 7.63 6.78 6.75
sowing year
Grass-clover 3.91 4.27 5.22 11.75
1st year
Grass-clover 4.86 6.48 9.98 20.47
2nd year
Sum 89.55 92.91 146.02 168.55
Mean (energy 12.79 13.27 20.86 24.08
input per year,
sum/7)
Mean% (CONFYM = 61 64 100 115
100%)
biodynamic bioorganic with manure without manure
Page 4 ATTRA Comparing Energy Use in Conventional and Organic Cropping Systems

5. This study found that “conventional crop • Organic crops still show a lower
yields were higher but they also used more energy per unit when energy input
indirect energy with input factors, espe- is analyzed per yield, but the dif-
cially fertilizers. The conventional yields ference is reduced due to the lower
were not sufficiently higher to compensate organic output. Organic carrots are
for the extra use of energy compared with more energy intensive due to flame
the organic crops.” (7) weeding and higher distribution
costs than conventional carrots. See
Learn more about this study at http:// Figure 2 for a graph of energy input
orgprints.org/6189/01/6189.pdf. by category on a unit output basis.
For livestock enterprises, energy input is lower
Department for Environment, in organic systems, particularly dairy. See
Food and Rural Affairs: Energy Figure 3 (next page) for a graph of direct
use in organic farming systems and indirect energy inputs into livestock
The United Kingdom Department for enterprises (8).
Environment, Food and Rural Affairs
(DEFRA) has conducted a number of stud- Figure 1. Energy input by category on an area basis (MJ/ha)
ies related to the sustainability of organic
agriculture systems. The objective of this
March 2000 report was to develop a model
of energy inputs in organic farming systems.
The model was used to compare energy
use in organic and conventional systems of
similar capacities. The model incorporated
average yield data from previous studies
including vegetables, dairy, beef and sheep.
This report also took into account energy
use associated with transportation.
Among the results found in this study, the
following points were established:
• Mechanical weeding of organic
crops involved less energy than
herbicides did in conventional
production. Figure 2. Energy input by category on a unit output basis (MJ/t yield)
• Flame weeding may involve as much
or more energy than herbicides.
• Transport energy inputs for organic
vegetable crops are greater because
of smaller production levels, smaller
delivered loads and longer average
distances to certificated organic
packing facilities.
• Organically grown crops have a
lower energy input per unit area
than conventional crops, largely
because of lower fertilizer and
pesticide inputs. See Figure 1 for a
graph of energy input by category
on an area basis.
www.attra.ncat.org ATTRA Page 5

6. Figure 3. Direct and indirect energy inputs into livestock enterprises conventional potato production
because cooling and storage account
for 40 percent of the energy use in
potato production for both organic
and nonorganic crops.
• Organic milk production appears to
require less energy but much more
land than conventional production.
It also creates more emissions of
greenhouse gases, acid gases and
eutrophying substances per unit of
milk produced.
• Organic production of beef, sheep
and pig meat is associated with
lower energy demands, but organic
poultry requires higher energy
inputs. See Table 3 (next page) for
more information.
The DEFRA report concludes that more
research needs to be done in order to more
For more information on this study, accurately determine the environmental
visit http://randd.defra.gov.uk/Document. impacts of organic and conventional foods (9).
aspx?Document=OF0182_181_FRP.pdf. This article received much press with titles
such as “Why going organic could cost the
Department for Environment, earth,” “UK research casts doubt on environ-
Food and Rural Affairs: mental claims” and “How green is organic?”
Environmental Impacts of Food In response, the Soil Association released a
Production and Consumption statement to assure consumers of the benefits
This 200-page report was released by of organic food. See the following summary
DEFRA in December 2006 with the objec- for details: http://randd.defra.gov.uk/Document.
tive of informing government policy about aspx?Document=EV02007_4601_FRP.pdf
reducing the environmental impacts of
food consumed in the United Kingdom. Soil Association responds to
Included in this study was an analysis of the Manchester Business School
the environmental impacts of organic ver-
sus conventional food systems in the United report: Environmental Impacts
Kingdom. The report states producing many of Food Production and
foods organically affects the environment Consumption
less than producing the foods conventionally. The Soil Association argued that organic
However, that is not true for all foods and farming is about 30 percent more energy effi-
is rarely true for all classes of environmen- cient for producing the same quantity of food
tal effects. The report said that not enough as conventional agriculture. In their argu-
evidence is available to state that organic ment, the association included the following
agriculture will have fewer harmful effects on list of food products and how much energy
the environment than conventional systems. an organic system required to produce the
More specifically, the DEFRA report food in comparison to a conventional system.
proposed the following: See Table 3 (next page) for more information.
• Organic potato production has The Soil Association also promoted the other
similar energy requirements to environmental benefits of organic agriculture,
Page 6 ATTRA Comparing Energy Use in Conventional and Organic Cropping Systems

7. Table 3. Energy used to produce food United Nations Food and
products in organic agriculture systems
compared to conventional systems Agriculture Organization: Energy
Use in Organic Food Systems
Leeks 58% less Onions 16% less This report, released in August of 2007 by
the Food and Agriculture Organization of
Milk 38% less Pig meat 13% less
the United Nations, used existing research to
Beef 35% less Potatoes 2% more examine the potential of organic and nonor-
ganic agricultural systems to reduce energy
Wheat 29% less Eggs 14% more consumption and mitigate climate change.
Tomatoes (long season) The study revealed the following points:
Carrots 25% less
30% more
• In most cases, organic agriculture
Lamb 20% less Chicken 32% more uses from 30 to 50 percent less
energy in production than compa-
including improved soil quality, supporting rable conventional agriculture.
local food markets, increased biodiversity and
reduced pesticide pollution, water usage and • Organic agriculture typically uses
packaging waste. For more information, energy more efficiently than nonor-
visit www.soilassociationorg/web/sa/saweb.nsf/ ganic agriculture.
89d058cc4dbeb16d80256a73005a2866/
80ca2af0ab639f5a8025728800608e08! • Organic agriculture often requires
Open Document. a bout one t h i rd add it iona l
human labor hours as a trade-off
University College Dublin: for energy-intensive inputs used in
Greenhouse Gas Emissions conventional agriculture.
from Conventional, The report indicated that further research
Agri-Environmental Scheme and is needed to determine whether reductions
Organic Irish Suckler-Beef Units in energy consumption on the production
In this study, 15 suckler-beef units in south- side of organic systems are maintained
ern Ireland were assessed in terms of green- through post-production processing, pack-
house gas emissions. The units included aging and transport.
five conventional, five organic and five
According to the Food and Agriculture
Rural Environmental Protection Scheme
Organization, “Organic agriculture holds
(REPS) systems. REPS was implemented in
a great potential for pioneering energy-
Ireland as a system for rewarding farmers that
reducing practices through the framework
adhere to strict guidelines regarding nutrient
management and habitat conservation. of organic standards. Organic principles,
which emphasize environmental stewardship,
Emissions factors considered included diesel farm-level self-sufficiency and incorpora-
fuel used, fertilizer applied, manure manage- tion of externalities, can be leveraged to
ment and electricity, among others. Results develop strategies for limiting use of fossil
of this study indicated that applying REPS fuel-based energy in organic agriculture.
systems would result in less greenhouse gas Especially in the areas of post-production
emissions in comparison to conventional handling, innovations in the organic supply
suckler-beef production. Emissions could chain to decrease energy consumption can
be reduced even more by applying organic influence parallel conventional sectors.” (2)
systems, but would result in a substan-
tial drop in production (10). For additional Visit www.fao.org/docs/eims/upload/233069/
information on this project, visit http://jeq. energy-use-oa.pdf for additional information
scijournals.org/cgi/content/full/35/1/231. on this research.
www.attra.ncat.org ATTRA Page 7

8. Conclusion cases. In some cases, organic agriculture
As is apparent in a review of existing may be more energy intensive depending on
studies, there are many complexities the specific farming operation, the crop pro-
involved in comparing energy consumption duced and the post-production handling. It
in conventional and organic cropping sys- is important to assess the energy intensive-
tems. Some research indicates that organic ness of food systems in a holistic manner
agriculture is more energy efficient than that incorporates energy consumption for
conventional agriculture, but not in all the entire life cycle of the food product.
References
1) Shoemaker, Robin, et al. 2006. Agriculture and Farming Systems. http://randd.defra.gov.uk/Document.
Rural Communities Are Resilient to High Energy aspx?Document=OF0182_181_FRP.pdf.
Costs. Amber Waves. April 2006. www.ers.usda.gov/
9) Department for Environment, Food and Rural
AmberWaves/April06/Features/Energy.htm.
Affairs. December 2006. Environmental Impacts of
2) Ziesemer, Jodi. August 2007. Energy Use Food Production and Consumption. http://randd.defra.
in Organic Food Systems. Natural Resources gov.uk/Document.aspx?Document=EV02007_4601_
Management and Environment Department, Food and FRP.pdf
Agriculture Organization of the United Nations. 10) Casey, J.W. et al. April 2005. Greenhouse Gas
www.fao.org/docs/eims/upload/233069/energy-use-oa.pdf. Emissions from Conventional, Agri-Environmental
3) Pimentel, David. August 2006. Impacts of Organic Scheme, and Organic Irish Suckler-Beef Units.
Farming on the Efficiency of Energy Use in Agri- University College Dublin. http://jeq.scijournals.org/cgi/
culture. An Organic Center State of Science Review. content/full/35/1/231
www.organic-center.org/reportfiles/ENERGY_SSR.pdf.
4) The Transition from Conventional to Low-Input Further resources
or Organic Farming Systems: Soil Biology, Soil Granatstein, David. Does Organic Farming Use Less
Chemistry, Soil Physics, Energy Utilization, Energy? Compared to what? Washington State Uni-
Economics, and Risk. November 2000. University versity. Presentation at the ACEEE Conference, Food
of California Sustainable Agriculture Research and and Energy from the Ground Up: Efficiency’s Role in
Education Program. www.sarep.ucdavis.edu/Grants/ Sustainable Agriculture, Des Moines, Iowa, February
Reports/Temple/temple88-225.htm. 20–22, 2008. www.aceee.org/conf/08ag/presentations/
DGranatstein.pdf
5) Reganold, John, et al. April 2001. Sustainability of
three apple production systems. Nature. Washington
State University. www.nature.com/nature/journal/v410/
n6831/full/410926a0.html. Comparing Energy Use in Conventional and
Organic Cropping Systems
6) Mader, Paul, et al. May 2002. Soil Fertility
By Holly Hill
and Biodiversity in Organic Farming. Science.
NCAT Program Specialist
Switzerland Research Institute of Organic Farming. © 2009 NCAT
www.mindfully.org/Farm/Organic-Farming-Fertility-
Holly Michels, Editor
Biodiversity31may02.htm. Amy Smith, Production
7) Refsgaard, Karen, et al. November 1997. Energy This publication is available on the Web at:
Utilization in Crop and Dairy Production in Organic www.attra.ncat.org/attra-pub/croppingsystems.html
and Conventional Livestock Production Systems. Agri- or
cultural Systems. Agricultural University of Norway. www.attra.ncat.org/attra-pub/PDF/croppingsystems.pdf
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