How will genetically modified seeds, crops and foods affect the
sustainability of U.S. agriculture? During 1999, agricultural
economist Charles Benbrook tried to answer that question.
Benbrook has a long history of analyzing all aspects of
agriculture as an employee of the executive branch, the Congress,
and the National Academy of Sciences, and more recently in the
Benbrook defines "sustainable agriculture" as a food system
** Provides a reasonable rate of return to farmers, to sustain
farm families, agricultural infrastructure, and rural
** Assures a reasonable rate of return to public and private
providers of farm inputs (seeds, fertilizers, etc.), information,
services, and technologies;
** Preserves and regenerates soil, water, and biological
resources upon which farming depends, and avoids adverse impacts
on the natural environment;
** Increases productivity and per-acre yields at least in step
with the growth in demand;
** Adheres to social norms and expectations in terms of fairness,
equity, compliance with regulations, food safety, and ethical
treatment of workers, animals, and other creatures sharing
First we should acknowledge that, by these criteria, U.S.
agriculture is not sustainable now and hasn't been for many
decades. Loss of profitability is almost always the immediate
cause of unsustainability in farming, Benbrook says. "All too
often in the U.S. in recent decades, the only thing that really
changes is that energetic and ambitious managers willing to
accept lower returns per bushel find the capital to expand,
maintaining their income only by expanding their acreage base,"
Benbrook says. Of course when one farm expands its acreage, often
another farm family has to move off the land. As a result, the
U.S. Bureau of the Census stopped counting "farm residents" in
1993 because there were so few of them left; their numbers had
dwindled to fewer than 2% of total U.S. population (4.6 million
people). (In contrast, in 1900, farm residents made up 35% of
Benbrook believes that genetically modified seeds, crops and
foods will amplify recent trends and will have the following
effects on farms:
** Increasingly serious economic surprises and setbacks for
farmers because many emerging biotechnologies are more expensive
to bring to market, for several reasons:
(a) Biotechnology results from mergers of seed companies and
pesticide companies. For example, as a result of a series of
acquisitions and mergers, DuPont and Monsanto together now own
73% of corn seed producers in the U.S. Seed companies have
traditionally had a relatively low profit margin (around 12% to
15%), whereas pesticide producers have had a higher profit margin
(20% to 30%). As pesticide companies try to raise the profit
margins of their newly-acquired seed companies up toward the
levels expected of pesticide companies, the cost of seed and
chemicals will probably continue to rise for farmers.
This has, in fact, been happening, Benbrook shows. In the
midwestern farm belt, corn and soybeans are the major crops.
Since 1975, for soybean farmers, the share of the farmer's gross
income per acre devoted to seed plus chemicals has risen more
than 50%, from 10.8% to 16.3%. For corn farmers, the increase has
been even larger (from 9.5% of gross income to 16.9%, 1975-1997).
(b) Genetically modified crops are requiring more herbicides than
farmers were initially led to believe they would, thus driving up
weed management costs. Take Roundup Ready crops. These are crops
genetically modified to withstand dousing with Monsanto's premier
weed killer, Roundup. The idea was that farmers would give their
crop one good dousing with Roundup and that would solve their
weed problems. Monsanto placed print ads telling farmers Roundup
was "the only weed control you'll ever need." You can see one of
these 1998 ads on the Iowa State University Herbicide Ad "Hall of
Shame" web site.
Roundup Ready crops offered farmers a modest reduction in costs
per bushel if everything worked as advertised. However, the
reality is different from what Monsanto promised in its ads.
Farmers using Roundup Ready crops find they have to use two or
three applications of two or more herbicides to control weeds.
Some farmers are finding they must use as many as four different
herbicides after planting a seed that supposedly makes weed
management easier. This disappointing trend is putting more of
farmers' income into the pockets of the seed and chemical giants.
As Charles Benbrook points out, the full Roundup Ready system is
now costing farmers "an amazing $68.77 per acre in 1999, about
50% more than the cost of [other] seed plus weed management
systems in the Midwest in recent years." This trend promises to
deliver "significantly lower average returns to growers,"
(c) Some weeds are developing resistance to Roundup -- notably
hemp weed or pig weed -- so Roundup is becoming less effective,
requiring additional measures for weed control, raising costs for
those relying on Roundup Ready crops.
(d) There is evidence that low-dosage herbicides can disrupt
beneficial soil microorganisms and perhaps interfere with plant
uptake of phosphorus, an essential nutrient. Benbrook believes
this can have an important negative impact on plant health and
(e) There is evidence of a "yield drag" associated with some
Roundup Ready crops, meaning that per-acre yields are not
consistently as high as it was once thought they would be. A
yield drag quickly translates into a profitability drag.
There are additional reasons why genetically modified crops are
likely to produce economic surprises and setbacks for farmers:
(f) The costs of creating and protecting intellectual property
are already high and they are bound to rise, Benbrook believes;
(g) The regulation of GMOs (genetically modified organisms) seems
likely to increase, and so will regulatory costs;
(h) Biotechnology is being promoted and used in a way that tends
to reduce diversity on the farm -- precisely the wrong direction
for farms to be going, in Benbrook's view. Successful pest
management requires a diversified system that spreads the burden
across differing mixes of chemical, biological, genetic, and
cultural (farming technique) tools and tactics. Reliance on a
single approach to pest management will fail because pests will
successfully evolve and thrive in response to single approaches,
(i) Trouble has appeared in another line of genetically modified
crops -- those containing the pesticidal Bt gene. Bt is a
bacterium that is toxic to a large class of common insect pests
called lepidopterans. Lepidopterans are butterflies and moths;
during the caterpillar stage of their life-cycle, lepidopterans
eat leaves and can cause great damage to leafy crops. Because of
the damage they inflict, lepidopterans provoke some of the
greatest use of pesticides world-wide.
Bt is a naturally-occurring killer of lepidopterans. As such, it
is a priceless gift from nature to row-crop farmers who need to
control outbreaks of lepidopterans. Charles Benbrook makes this
comparison: Bt is to the control of lepidopterans what
antibiotics are to the control of human diseases. If Bt loses its
effectiveness, it will have major consequences for vegetable
farmers across the U.S., many of whom use Bt (in one form or
another) as a foliar spray.
By inserting a gene from the Bt bacterium into plants, Monsanto
and others have created crops that are themselves pesticidal to
lepidopterans. For example, Monsanto's "New Leaf" potato, which
is now sold in U.S. grocery stores, is itself a registered
pesticide because every cell in every potato contains the Bt
gene. (Notably, it is one of the few registered pesticides
that is not labeled as such.)
From the beginning, Monsanto and others have acknowledged that
their Bt-containing crops might conceivably induce Bt resistance
among lepidopterans, but they have insisted that the likelihood
is "remote." Resistance is a well-understood phenomenon. When a
group of insects is sprayed with a poison, those that are least
affected survive and reproduce. Soon the only remaining insects
are unaffected by that poison -- they have developed resistance
When Monsanto approach EPA [U.S. Environmental Protection Agency]
for permission to market Bt-containing plants, they came armed
with numerous studies showing that resistance to Bt might take 30
years to develop, if indeed it developed at all. Because
genetically-engineered Bt-containing crops had been developed in
almost total secrecy, when EPA asked for public comment on
Monsanto's proposal, the nation's agricultural experts had little
to say. EPA assumed their silence meant all was well.
Traditionally, farmers get reliable information from the land
grant colleges that Congress created in 1862. However, beginning
with the Freedom to Farm Act of 1996, Congress has systematically
reduced the role of the public sector in U.S. agriculture. Now
development of genetically engineered crops is largely in private
hands and the new technology is cloaked in secrecy. The veil of
secrecy "raises an important public policy issue," says Benbrook.
"When scientists are unwilling to share data, are constrained in
what they can report, and/or have no opportunity to study new
technology, public institutions and regulators have to fly blind
for a period of time." So, flying blind and basing its decision
on Monsanto's science, EPA approved crops with the Bt gene
inserted into them.
Now it turns out that Monsanto's science was woefully weak and
incomplete. New studies show that resistance to Bt is not nearly
as rare in lepidopterans as Monsanto claimed it was, so
resistance can be expected to develop much more rapidly than
Monsanto initially projected. Furthermore, it is now clear that
Bt-corn can adversely impact populations of key beneficial
insects. Lacewing larvae, which eat lepidopteran larvae, are
killed by Bt, thus removing a natural control on lepidopterans.
It now seems clear that farmers who become reliant upon
genetically modified crops containing the Bt gene can expect
unpleasant surprises in the short term and loss of the
effectiveness of Bt in the medium term. It will be a grave
In sum, genetically modified crops seem poised to reduce
diversity on farms, reduce farm profits, and make U.S. farms even
less sustainable than they already are. For the U.S. food system,
this hardly seems like progress.
CORRECTION: PRECAUTION IN LOS ANGELES SCHOOLS
We owe an apology to the Los Angeles Safe Schools Coalition
(LASSC) who did the work that resulted in the path-breaking new
pesticide policy adopted last year by the Los Angeles Unified
School District, which we described in Rachel #684.
The new policy says Los Angeles schools will look for the least
damaging way to control pests, in accord with the precautionary
principle, and that the goal is to control pests by non-chemical
means whenever possible. The policy represents a major step
forward in environmental decision-making.
LASSC is a coalition of 20 organizations, including Pesticide
Watch, Physicians for Social Responsibility, United Teachers Los
Angeles, the Parent Teachers Association, and Action Now.
Six individuals made up the core group that successfully
persuaded the Los Angeles Unified School District that "better
safe than sorry" is the best pest management philosophy:
** Dr. Kirk Murphy of Physicians for Social Responsibility, who
inserted the precautionary language into the draft policy;
** Sandy Schubert, a lawyer who negotiated the terms of the
policy. Though not a member of any of LASSC's constituent
groups, she contributed her writing skills and her extensive
knowledge of California pesticide policies
** Robina Suwol, a parent who saw her child disappear in a cloud
of pesticidal fumes as she dropped her child off at school one
day; her tenacity and commitment ultimately drove the coalition
** Yvonne Nelson, a member of Action Now, who culled through
reams of school pesticide-use reports and documented the
widespread mis-use of pesticides in Los Angeles schools;
** Christina Graves, a community organizer with Pesticide Watch,
hired to help the coalition find the political strength it needed
to overcome the opposition of the pesticide corporations and
their friends in high places.
We implied in Rachel #684 that the new pesticide policy in Los
Angeles resulted from efforts by Californians for Pesticide
Reform (CPR). CPR and Pesticide Watch jointly raised the funds
that paid the community organizer who helped build LASSC, and CPR
generated support and publicity for the new policy at a crucial
moment, just as it came up for a vote. But LASSC worked
tirelessly for two years to make the new policy a reality and it
is they who deserve the credit for this important public policy
--Peter Montague (National Writers Union, UAW Local 1981/AFL-CIO)
 Charles M. Benbrook, "World Food System Challenges and
Opportunities: GMOs, Biodiversity, and Lessons From America's
Heartland," unpublished paper presented January 27, 1999, at
University of Illinois. Available in PDF format at http://-
www.pmac.net/IWFS.pdf Dr. Benbrook gave a talk based on his
paper; if you have an audio-enabled computer, you can listen to
the talk and see the slides via the world wide web:
 During the early 1980s Benbrook served as an agriculture
policy analyst for the President's Council on Environmental
Quality, then as staff director of the Subcommittee on Department
Operations, Research and Foreign Agriculture of the Agriculture
Committee of the U.S. House of Representatives; from 1984 to 1990
he was executive director of the Board of Agriculture, National
Academy of Sciences. Since 1990 he has operated Benbrook
 David Tilman, "The Greening of the Green Revolution," NATURE
Vol. 396 (November 19, 1998), pgs. 211-212.
 Associated Press, "Too Few Farmers Left to Count, Agency
Says," NEW YORK TIMES October 10, 1993, pg. 23.
 Ann M. Thayer, "Ag Biotech Food: Risky or Risk Free?"
CHEMICAL & ENGINEERING NEWS [C&EN] November 1, 1999, pgs. 11-20.
 The amazing story of the New Leaf pesticidal potato was told
in Michael Pollan, "Playing God in the Garden," NEW YORK TIMES
MAGAZINE October 25, 1998, pgs. 44-51, 62-63, 82, 92-93.
 On Bt resistance, see http://www.pmac.net/ge.htm.
Descriptor terms: agriculture; farming; biotechnology; pesticides;
herbiocides; resistance; genetic engineering; bt; roundup ready;
monsanto; dupont; charles benbrook; economics;