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.
 |
|
Lower
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 technology—
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 the technology:
• 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 percent.
• 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 report.
|
