If only 10,000
medium sized farms in the U.S. converted
to organic production, they would store
so much carbon in the soil that it would be equivalent
to taking 1,174,400
cars off the road, or reducing car miles
driven by 14.62 billion miles.
the U.S.’s 160
million corn and soybean acres to organic production
would sequester enough carbon to satisfy
73 percent of the Kyoto targets for CO2
reduction in the U.S.
U.S. agriculture as currently practiced emits a total
of 1.5 trillion pounds of CO2
annually into the atmosphere. Converting
all U.S. cropland to organic would not
out agriculture's massive emission problem.
By eliminating energy-costly chemical fertilizers, it
give us a net increase in soil carbon of 734 billion
As some of you may know, The Rodale Institute®,
which publishes The New Farm®,
is home to the longest running field trials in the country
comparing organic and conventional systems of farming
Rodale Institute Farming Systems Trial® (FST).
The data from that 23 years of research is a real treasure
trove of insight into the economic, ecological and agronomic
benefits of organic farming.
In addition to the long-running FST, we have a variety
of other research in progress at The Institute. David
Douds has been studying soil fungi here at The Institute’s
research farm for 15 years. (Go to Cultivating
diversity underground for better yields above for
more on David's research.) We’re engaged in no-till
research, weed research, compost tea research, composting
research, water quality research, and much more.
Until now, much of the light we’re generating
here on our research farm has been hidden under the
proverbial barrel, but we’re taking off the barrel
and busting it up for firewood. We’re going let
the light of the amazing research being done here shine
on farmers, consumers and environmental activities.
Over the next year we’ll be running a series
of stories, about one a month, on the significance of
our research ... and its practical applications. That
includes a few stories on equipment construction—a
front-mounted roller for no-till, and a compost turner
converted from a junked 18-wheeler.
So sit tight, and be prepared to be amazed.
The Rodale Institute®
announces a partnership with Pennsylvania's Department of Environmental
Protection and Department of Agriculture to explore ways these findings
can benefit farmers and the environment. One possibility: carbon
credits could be in your agricultural future.
OCTOBER 10, 2003: Kutztown, PA Discussions of
global warming in the popular press seldom fail to note its potentially
disastrous consequences for agriculture as we know it: more extreme
and unpredictable weather, coastal flooding, even the loss of pollen
viability for some crop species at higher temperatures all threaten
to push the usual unpredictability of farming into the realm of
the completely unworkable. But while these threats are indeed grave--and
many farmers believe they are witnessing such effects already--researchers
at The Rodale Institute® have been looking at the problem from
the other direction: what impact do agricultural practices have
on global warming?
On October 10, The Rodale Institute® (TRI), the Pennsylvania
Department of Environmental Protection (PDEP), and the Pennsylvania
Department of Agriculture (PDA) signed a memorandum of understanding
designed to help answer that question. Twenty-three years of ongoing
research at The Rodale Institute Experimental Farm already provides
strong evidence that organic farming helps combat global warming
by capturing atmospheric carbon dioxide and incorporating it into
the soil, whereas conventional farming exacerbates the greenhouse
effect by producing a net release of carbon into the atmosphere.
The key lies in the handling of organic matter (OM): because soil
organic matter is primarily carbon, increases in soil OM levels
will be directly correlated with carbon sequestration. While conventional
farming typically depletes soil OM, organic farming builds it through
the use of composted animal manures and cover crops. Now, in a unique
new partnership, PDEP, PDA and The Rodale Institute are interested
in working together to see how organic farming practices can be
used to help Pennsylvania--and the world--curb greenhouse gases.
In recent months, TRI Research Manager Paul Hepperly and President
John Haberern have drafted a White Paper summarizing TRI's research
findings and their relevance to global climate change. The formal
agreement, signed last Friday, will provide a platform for further
research into the environmental and economic benefits of organic
and sustainable farming. By coordinating with PDEP and PDA, Haberern
explains, "we can undertake a systematic review of all the
existing data on this issue, and examine how the process could be
What they learn could be used in reclaiming strip-mined areas of
Pennsylvania or in processing waste materials, as well as in improving
the state's farming practices. As a regional leader in the agricultural
management community and a global leader in sustainable agriculture,
TRI also hopes to play an active role within the Northeast Greenhouse
Gas Region recently designated by the US Department of Energy.
What we know already:
23 years, there’s been a 15 to 28% increase in soil carbon
in organic systems, with virtually no increase in non-organic
The data demonstrating that organic farming practices can reduce
atmospheric carbon levels come from TRI's longest-running field
study, The Rodale Institute Farming Systems Trial®
(FST). Launched in 1981, the FST is a 12-acre, side-by-side experiment
comparing three agricultural management systems: one conventional,
one legume-based organic, and one manure-based organic. In 23 years
of continuous recordkeeping, the FST's two organic systems have
shown an increase in soil carbon of 15-28%, while the conventional
system has shown no statistically significant increase. For the
organic systems that translates into more than 1000 lbs of captured
C (or about 3670 lbs of CO2) per acre-foot
per year—and that’s not even counting the reductions
in CO2 emissions represented by the organic
systems' lower energetic requirements. A comparative analysis of
FST energy inputs, conducted by Dr. David Pimentel of Cornell University,
found that organic farming systems use just 63% of the energy required
by conventional farming systems, largely because of the massive
amounts of energy required to synthesize nitrogen fertilizer.
"Results like these are a bright spot within the otherwise
dreary picture of global climate change research," notes Daniel
Desmond, Director of the Office of Pollution Control at PDEP. Organic
farmers "are the only group or philosophy that looks at carbon
as a resource rather than carbon as a waste product."
just how much carbon dioxide can
organic farming take out of the air each year?
Think of it in terms of the equivalent # of cars that
would be taken off the road each year by farmers converting
to organic production. Organic farms sequester as much
as 3,670 pounds of carbon per acre-foot each year. A
typical passenger car, according to the EPA, emits 10,000
pounds of carbon dioxide a year (traveling an average
of 12,500 miles per year). Here's how many cars farms
can take off the road by transitioning to organic:
if all 160 million acres of conventinal corn and soybeans
in the U.S. were converted to organic production, that
could translate to:
- 58.7 million cars off the road! (25% of the national
- That's 733,750,000,000 car miles not driven...or
116,666,666 round trips from New York City to Los
Angeles not taken!
if all 431 million acres of U.S. cropland
were converted to organic:
- 158,177,000 cars would be taken off the road (over
half of the national total)
- 1.98 trillion car miles not driven.
Global climate change and the carbon cycle
While a handful of political conservatives continue to dispute
the seriousness of global warming and the necessity for a concerted
international effort to mitigate its effects, the vast majority
of scientists have concluded that global climate change is a reality:
- Atmospheric carbon dioxide levels--the major factor in the
greenhouse effect--are now twice as high as they were during the
last Ice Age, have risen from 280 parts per million (ppm) to 365
ppm in the last two centuries alone, and are now increasing at
a rate of 1.3 ppm per year.
- Consumption of remaining fossil fuel reserves would boost CO2
by a factor of four to eight.
- Other greenhouses gases, including methane (CH4),
nitrous oxide (N2O), and chlorofluorocarbons
(CFCs), have also proliferated and would take decades to stabilize
even if emissions were magically cut tomorrow.
- Global mean surface temperatures have climbed 0.6ºC since
the 1850s and are expected to rise 1.5 - 5.0ºC by 2100. Paleoclimatic
evidence indicates that the 1990s were the warmest decade since
the year 1000.
In their efforts to understand and to address the effects of global
warming, scientists are developing an increasingly sophisticated
picture of the global carbon cycle. Total carbon storage provided
by different parts of the global system--terrestrial vegetation,
the surface ocean, the deep ocean--have been quantified, as have
the annual fluxes of carbon among them. CO2
emissions from human and animal activities now stand at about 8.9
billion U.S. tons per year, while net atmospheric CO2
accumulation is 3.5 billion US tons. In other words, 40% of annual
human-induced carbon emissions contribute to build-up, while the
remaining 60% are absorbed by the oceans and terrestrial plants.
Reforestation not enough to handle rise in greenhouse
gas emissions. Farmlands are a better carbon “sink.”
Proposals to expand natural carbon sinks as a partial remedy for
global warming initially focused on reforestation. Changes in land
use, including the loss of forests to tillage and grazing, were
known to be a major contributor to the greenhouse effect--as recently
as the 1970s, total accumulated C emissions from land-use change
exceeded total emissions from the burning of fossil fuels--and it
was thought that escalating fossil fuel consumption could be balanced
by vast forests breathing in all that CO2.
Data like those emerging from the Farming Systems Trial, however,
are revising that image: It may be that the soil itself makes more
of a difference than what's growing in it. On a global scale, soils
hold more than twice as much carbon (an estimated 1.74 trillion
U.S. tons) as does terrestrial vegetation (672 billion U.S. tons),
and practices like reduced tillage, the use of cover crops, and
incorporation of crop residues can dramatically alter the C storage
of arable lands.
to get from a net loss of soil carbon to a net gain
in one easy step!
Dr. David Pimentel, Cornell University’s specialist
in analyzing energy expenditure in agricultural systems,
calculates that U.S. agriculture currently emits about
925 billion pounds of carbon dioxide each year from
crop and livestock production. So, what would happen
if all those U.S. acres converted to organic production?
"Agriculture and forestry are a very potent sink--they will
make the emissions problem easier to get a handle on," explains
Haberern. "Especially if you do the agriculture right. If you
practice conventional agriculture, then any low to non-existent
C gain you get will have to have subtracted from it the C emissions
created by conventional agricultural methods. With organic farming
it can be pure gain. Using bio-diesel [for tractor power], you don't
need to use any fossil fuels at all."
Organic farming for carbon capture is also compatible with other
environmental and social goals such as reducing erosion, minimizing
impact on native ecosystems, and improving farmer livelihoods. Compared
to forests, moreover, agricultural soils may be a more secure sink
for atmospheric carbon, since they are not vulnerable to logging
Although it is well established that sustainable and organic farming
methods sequester atmospheric carbon, researchers have yet to flesh
out the precise mechanisms by which this takes place. In the FST,
soil carbon levels increased more in the manure-based organic system
than in the legume-based organic system, presumably because of the
incorporation of manures, but the study also showed that soil carbon
depends on more than just total C additions to the system--cropping
system diversity or carbon-to-nitrogen ratios of inputs may have
an effect. "We believe that the differences in decay rates
[of soil organic matter] have a lot to do with it," says Hepperly,
since "soluble nitrogen fertilizer accelerates decomposition"
in the conventional system.
On the other hand, the work of another Rodale research collaborator,
Dr. David Douds of the Agricultural Research Service, suggests that
healthy mycorrhizal fungi populations in the organic systems slow
down the decomposition of organic matter. (Visit Cultivating
diversity underground for better yields above for more on Douds'
mycorrhizal research.) All of these factors lead Hepperly to conclude
that "it's crucial to look at the biological nature of the
soil carbon system," rather than just to consider it as a geochemical
Should organic farmers get 'carbon credits'?
A further goal of the partnership between The Rodale Institute,
the PA Department of Agriculture and the PA Department of Environmental
Protection is to explore policy mechanisms by which farmers and
landowners could quantify the carbon sequestered on their properties
and receive a payment from the state or federal government for ecosystem
services provided, or even participate in emerging 'carbon-trading'
markets around the world. Although the development of carbon-trading
markets in the US was put on hold by the Bush administration's decision,
in 2001, to pull out of the Kyoto Protocol (citing projected deleterious
effects on the struggling US economy), such markets are rapidly
expanding in the European Union and elsewhere. (See, for example,
co2e.com, a greenhouse
gas brokerage firm based in London.)
"The Kyoto Protocol [the 1997 global agreement to reduce greenhouse
gases] talks about agriculture and forestry as carbon sinks, but
fails to distinguish between the different effects of different
types of agriculture," notes Daniel Desmond of the PA Department
of Environmental Protection. In fact, the whole business of credit
for carbon-sequestration activities under the Kyoto accord is problematic,
because of the lack in 1997 of good carbon inventory data that could
be factored into the nation-by-nation emissions-reduction targets.
Nevertheless, although sequestration in agricultural soils can
vary by climate and by soil type, multiplying 3,670 pounds of captured
CO2 per acre across the 160 million acres
planted to corn and soybeans in the US yields a potential CO2
capture on the order of 293 million tons per year, or as much as
three-quarters of the reductions required if the US were to adhere
to its Kyoto targets. (Total U.S. cropland is 431 million acres.)
farming -vs- the Kyoto targets
In 1997 the U.S. agreed to reduce 1990 levels of CO2
by seven percent. So here's a question: How far would
converting U.S. cropland to organic take us toward satisfying
those Kyoto goals? Let's do the math:
Converting 160 million acres
and soyean to organic results in
tons of CO2 stored in soil
ton reduction in CO2
Percentage of Kyoto goal that
satisfied by converting to organic:
doesn't even take into consideration the drastically
reduced energy expenditure and CO2
emissions of organic farming compared with using chemical
Thinking globally, the British Royal Society has estimated potential
CO2 sequestration on the world's 2.5 billion
acres of agricultural soils at 6.1 to 10.1 billion U.S. tons per
year for the next 50 years. Another estimate puts the total amount
of CO2 that could be captured in developing
countries at 1.7 billion U.S. tons over the next decade. In short,
carbon sequestration via adoption of organic agriculture could have
a substantial impact on global warming.
Still, carbon sequestration by organic farming, like carbon capture
through reforestation, is a short-term or 'bridge' solution, a way
of buying time for more fundamental changes. Ultimately, global
climate change can only be fully addressed through rationalization
of energy policies, reductions in fossil fuel consumption, and improvements
in emissions-control technologies. Among the possible short- to
medium-term solutions, however, organic farming has a lot going
for it. "There are a number of 'Star Wars'-like solutions being
proposed" for carbon and carbon dioxide capture, observes Hepperly,
including pumping CO2 deep into the ocean
or underground--in July of this year the US Department of Energy
announced that drilling had begun on a 10,000-ft 'well' to funnel
CO2 deep beneath West Virginia.
Compared to expensive, experimental, high-technology projects like
these, global transitioning to organic farming looks cheap and easy.
"It's a no-brainer," Hepperly concludes. "Organic
farming is not a technological fix, not an untried experiment that
could have its own unforeseen consequences." Instead, it's
a step toward solving global warming that brings with it a wealth
of other environmental benefits.