September 28, 2004:
Flat soybean yields since the mid ’90s, followed by a drastic
drop in 2003, have many farmers wringing their hands and some agronomists
searching for answers.
The flat yields since 1995 have cost conventional U.S. soybean
farmers an estimated $1.28 billion, according to a report entitled
“Stagnating National Bean Yields” The report—presented
at the 2004 Midwest Soybean Conference in Des Moines, Iowa, last
August—first described historical yield trends, then went
on to explore potential causes for the downward spiral, including
erratic weather patterns, increased marginal acreage under production,
and genetic changes.
From 1972 to 1993, according to the report, soybean yields increased
.45 percent each year. Those yields peaked in 1994, then went flat
until 2003, when they dropped by 5.88 bu./acre.
“We went to seed companies and they confirmed that yields
have leveled off,” said Ron Eliason, who headed up a consortium
of farmers funding the study. “We asked ‘Is this a trend
you see?’ And they said ‘yes.’ For most of these
people, this was anecdotal. The statistics...sort of got their attention.”
The report also looked at severe weather patterns—including
early season dry spells and heavy August rain—as a possible
cause for the drop in yields. But the statistical data showed that
there was not enough variation from other years to account for such
a radical shift. “In other words, our conclusion was that
there’s something going on in soybeans that is not explained
by the weather,” Eliason said.
The report went on to speculate that conventional soybeans may
have performed better in 2003 than some genetically modified (GM)
hybrids. “There are some things that happened since 1995 that
would lead you to look into that area,” Eliason told New Farm
during a telephone interview. “I don’t want to get into
that controversy…but anytime you get into genetically engineering
a plant, that takes energy.”
What’s the connection?
In 1996, Monsanto introduced its Roundup Ready gene into the soybean
market, patenting a genetically engineered plant that was resistant
to the company’s own Roundup Ready herbicide (glyphosate).
That year, 7 percent of all soybeans planted on U.S. soil were Roundup
Ready. By 2004, that figure had risen to 85 percent.
The promises of Roundup Ready soybeans—for which farmers
are required to sign elaborate contracts, pay licensing fees and
a premium for the technology, and face stiff penalties for saving
seed—included better weed control with lower pesticide use,
less labor in the fields, and improved yields.
Those claims have fallen short. While weed control has been improved
with less labor, new glyphosate-resistant ‘super weeds’
are now developing as a result of overuse of the herbicide (studies
have shown that farmers growing Roundup Ready soy use 2 to 5 times
more herbicide than farmers growing other varieties). Perhaps most
critical to farmers, yields have gone down.
While flat or even lower yields from one year to the next do not
necessarily mean a smaller paycheck for the farmer—that’s
determined by market forces—if farmers are paying a premium
for a technology that promises higher yields while it actually reduces
them, that could have a significant bearing on their bottom line.
The report at the Midwest Soybean Conference also considered as
possible causes for crop losses a new aphid problem and the fact
that soybean plantings on marginal lands have increased by 12 million
acres since 1996 (some researchers say soybeans do not belong in
such areas because they are erosive).
Soybeans do tend to perform better than some other crops on marginal
lands, said Paul Hepperly, research director at The Rodale Institute,
where experiments comparing soybean yields in conventional and organic
systems have been under way for more than two decades.
As for the aphid problem, Hepperly pointed out that when a Roundup
Ready soybean plant is sprayed with glyphosate it turns yellow,
then gains back its green color as the plant recovers. Aphids are
typically attracted to yellow plants, he said. “Aphids never
before used to be a problem on soybeans,” Hepperly said. “Are
these aphids to some extent a consequence of the changes that affected
the metabolism of the plants?
“Roundup inhibits the pathway that produces 35 percent of
the metabolites. When they’re blocking the normal interaction
of that pathway, they’re playing with things that affect the
immune system of that plant.”
And that could make those plants less resistant to pest and disease
problems, Hepperly said. Technologies such as Roundup Ready are
typically developed in best-case-scenario environments that bolster
performance but seldom reflect real-farm pressures, he said, pointing
out that the problems now developing with Roundup Ready soy are
mostly related to stress factors in an uncontrolled environment.
Hepperly questioned whether the new pest, root rot susceptibility
the other problems now plaguing soybean farmer might be related
to a new production system skewed toward what’s easiest to
produce, not necessarily what’s most productive.
And he’s not alone.
yields may be just the tip of the iceberg
By Dan Sullivan
Unintended consequences of genetic engineering such
as lower yields, woody stems, disease susceptibility,
invasive super weeds, genetic pollution and a host of
unknowns have led many scientists, consumer groups,
and environmentalists to question the wisdom of unleashing
such technologies before they have been proven safe.
Those sounding the alarm assert that proper scientific
precautions were sidestepped by biotech companies eager
to get their products to market, arm in arm with industry-tied
government regulators. Now, they say, the consequences
of this rush to market are unfolding.
Predictions about the adverse effects of Roundup Ready
and other genetic technology play out daily in the media.
This summer, Arkansas Extension agents added ragweed
to the list of invasive weed species developing a tolerance
to glyphosate—leading to more, not less, use of
herbicides. And for the first time, the USDA has ordered
a full-blown environmental impact statement on a genetic
Roundup tolerant creeping bentgrass destined for golf
courses and residential lawns—after research showed
that pollen from the genetically engineered grass can
travel at least 13 miles. (U.S. Forest Service officials
were quoted in the The New York Times as saying genetically
engineered creeping bentgrass “has the potential
to adversely impact all 175 national forests and grasslands.”)
While Roundup Ready corn is a reality, most U.S.-grown
genetically modified corn is engineered to produce the
bacteria Bacillus thuringiensis (Bt). Bt produces crystals
and spores that paralyze the digestive tract of certain
insect larvae, specifically the European corn borer.
Organic farmers and gardeners have historically (and
discriminately) applied Bt powder when pests are at
their larval stage.
Bt modified corn presents several concerns. Like the
Roundup Ready gene, there’s no telling what impact
the constant presence of Bt will have over time on mycorrhizae,
rhizobia, and other soil and root microorganisms key
to building healthy soil and to delivering proper nutrition
to plants. No one disputes that Bt running through the
entire plant for its whole life cycle, then being absorbed
back into the earth as the plant decays will eventually
lead to more rapid resistance by the pests it now controls.
And the potential consequences to humans of eating Bt
corn—like so many variables surrounding genetic
engineering—are unknown (45 percent of all corn
planted in the U.S. in 2004 was genetically engineered).
In 2002, British scientists at the University of Newcastle
discovered DNA material from genetically engineered
plants in human gut bacteria. Asides from the dangers
the Roundup Ready and Bt genes may themselves present
to human health, many of the GE crops also contain antibiotic-resistant
marker genes. Some scientist fear a buildup of such
materials would eventually sabotage a person’s
ability to fight off infection.
Last year, Norwegian scientist Terje Traavik, Ph.D.,
linked flowering Bt corn to a wave of illnesses in the
southern Philippines. Criticized for going public with
his findings before they had been peer reviewed, Traavik
now claims he’s found human antibodies to the
Bt toxin in blood samples taken from people who had
complained of illness the year before.
In August, a federal judge ordered the USDA to disclose
where four companies are performing open field testing
in Hawaii on crops genetically engineered to produce
pharmaceuticals, after community members on the island
of Moloka’i complained of similar—though
inexplicable—allergic reactions. (Experimental
crops from so-called ‘biopharms’ in the
Midwest have already accidentally been mixed with other
stored grains destined for human consumption.)
Pollen drift from genetically engineered crops continues
to contaminate neighboring conventional and organic
crops, leading to rejection of those crops on domestic
and foreign markets.
And genetic pollution by engineered crops—as
demonstrated by contaminated native corn in Mexico and
native sunflowers in the U.S.—threatens the integrity,
perhaps the very existence, of these species.
“The [introduced] gene action eliminates the
normal evolution of genetic expression,” said
Paul Hepperly, a plant breeder and research director
at The Rodale Institute. Evidence suggests that these
natives will favor the new gene and select away from
other mechanisms, he said.
“You no longer have the ability to select for
natural resistance in native crops, which is where people
have traditionally gone when there’s been a problem.”
“There have been myriad factors at work,” said Mike
Duffy, Ph.D., an Extension economist at Iowa State University. “To
lay it all at the doorstep of Roundup Ready is probably a stretch.
I think that could be part of it.
“Early studies showed a yield drag associated with Roundup
Ready; that, I think, has been largely overcome. Then we kind of
almost moved into this ‘pest du jour’ phase, with aphids,
root rot, white mold, sudden death—you name it, something
was coming along.
“I’ve kind of got a gut feeling that we were putting
research dollars into looking more at genes and not as much at yields.
As a result, I think we may have seen some slippage in that way.
To say it’s all Roundup Ready’s fault, I don’t
think that would be right. But to say that’s part of it, I
would have to agree with that.”
Research connecting Roundup Ready soybeans to pest and production
problems has plagued Monsanto almost since the company introduced
• Fusarium fungi are not uncommon in soybeans, and population
levels typically fluctuate. But University of Missouri researchers
conducting experiments between 1997 and 2001 found that Roundup
Ready soybean fields sprayed with glyphosate had abnormally increased
levels of the fungi, a condition that can lead to a host of problems
for the plants, including sudden death syndrome (SDS) and other
root rots. (Since that study, research in Canada has also connected
glyphosate use to fusarium head blight in wheat.)
• Research at the University of Georgia in 1999 showed that
Roundup Ready soybeans exhibited an unintended 20 percent increase
in lignin, making them overly woody and causing stem splitting (particularly
in high heat), resulting in crop losses in the South of up to 40
• And, following two years of field research, University
of Nebraska researchers concluded in 2000 that Roundup Ready soybeans
were yielding 6 percent less than their closest relatives (hybridized
plants that were exactly the same, minus the Roundup Ready gene)
and 11 percent less than high-yielding conventional varieties. Agronomist
Roger Elmore, Ph.D., and his colleagues calculated those losses
equal to about 3 bushels per acre.
Not all at the 2004 Midwest Soybean Conference spelled gloom and
doom for conventional soybeans. Scott Abney, Ph.D., a plant pathologist
from Purdue University and also a speaker at the conference, held
out hope of getting the yields back on track through cooperative
breeding programs that boost plant qualities such as disease and
drought resistance as well as “overall agronomic performance.”
Jim Specht, another University of Nebraska agronomist, presented
research that showed that the corn-to-soybean ratio (roughly 3.2
to 1) had remained generally constant from 1972 to 2003 (noting
the anomaly years of 1994 and 2003).
Representatives at Monsanto did not return phone calls for this