systems utilize water much more effectively
“The organic soils at our farm soak up precipitation
much more effectively,” says Bill Liebhardt, Research
Director at The Rodale Institute. “This means
less erosion of soil, less silting of streams, less
flooding and no new pesticide residue moving into surface
“At the same time, our non-conventionally farmed
soils that are rich in organic matter absorb water much
better, storing it longer in dry seasons and allowing
less agricultural water to move downward into the groundwater,”
he said. “Again, these fields have no herbicide
(weed killing chemicals) applied, so no residue flows
into the groundwater that provides drinking water for
so many millions of Americans.”
Liebhardt is completing a two-year analysis comparing
water quality in side-by-side, long-term trials of conventional
and organic grain production. Technicians at The Institute
are gathering data from the 21-year-old Farm Systems
Trial (FST) and the 10-year-old Compost Utilization
The comparison shows that herbicides give more consistent
weed control in the conventional plots, but over the
trial period, did not deliver greater yields. The pesticide-free
organic field plots had more weeds, but end up yielding
as well as the conventional areas. And with potential
price we pay in human health for pesticide pollution,
that equality of yield may be very significant.
||OCT. 15, 2002,
KUTZTOWN, PA: At much lower levels than previously thought,
common agricultural pesticides in groundwater can harm frogs, mice
and possibly humans, especially during early development in utero.
Organic farming, however, creates water-absorbent soil and does not
add to this pesticide residue in groundwater, according to Dr. William
Liebhardt, research director at The Rodale Institute.
New data from The Institute's long term Farm Systems Trial (comparing
conventional and organic systems) show atrazine levels in water
from conventionally farmed soil that exceed concentrations now shown
to harm organisms. Further, this documented injury comes at concentrations
lower than the US-EPA safe drinking water standard.
Dr. Liebhardt said a report from Rodale Institute, due out next
spring for farmers, landowners and policy makers, will detail the
significant differences seen in organically farmed soils at the
farm, located in Kutztown, Pa. Further, the report will highlight
the health implications of how agricultural pesticides are used
by farmers across North America.
More than 60 million pounds of the herbicide were applied last
year in the United States alone. Manufacturer Syngenta estimates
that farmers use the herbicide to control weeds on about two-thirds
of all U.S. corn and sorghum acreage. On average, it improves corn
yield by slightly more than 4 percent. The compound has generally
been considered safe because it quickly decomposes in the environment
and, being water soluble, is quickly excreted from the body. However,
new research identifies unexpected effects that are not so benign.
Most significantly, two recent studies indicate that Atrazine residue
in groundwater and surface waters has harmful effects in combinations
that it does not have on its own. This indirect effect reveals a
weakness in current safety testing on ecological and health impacts
of herbicides prior to release of new materials.
Liebhardt cites three researchers who have found that herbicides
in groundwater have a detrimental impact on animals and possibly
humans. They lend some urgency to The Institute's research documenting
that organic production prevents herbicide and pesticide pollution
- Warren P. Porter, of the University of Wisconsin, and others
reported in 1999 that common ag chemicals in a groundwater mixture
with each other and nitrates had detrimental impacts together
that they did not have individually. The mixtures, including herbicides,
had negative effects on the nervous, immune and endocrine (hormone)
systems of mice in a five-year study.
Impacts showed up as suppressed immune function, altered thyroid
levels hormone levels and behavior (increased aggression) changes.
Other studies show other chemical contaminants induce similar
health risks, and that these together may contribute to human
developmental injury prior to birth. Results could include attention
deficit and/or hyperactivity disorders, autism syndromes, multiple
chemical sensitivity, elevated irritability, and aggressive behavior.
an Interview with helpful explanations of human risks
- Tyrone B. Hayes, of the University of California at Berkeley,
and others, reported in April that Atrazine disrupts the sexual
development of frogs at concentrations 30 times lower than levels
allowed by the US-EPA. At frequently occurring environmental levels,
the pesticide demasculinizes tadpoles, turning them into hermaphrodites
with male and female sexual characteristics. Atrazine lowered
levels of the male hormone testosterone in adult male frogs by
a factor of 10, according to a report from the National Science
In the NSF story, Hayes said “The use of atrazine in the
environment is basically an uncontrolled experiment – there
seems to be no atrazine-free environment.” He doubts that
atrazine’s impact on humans is as severe, because of all
the time frogs spend in direct contact with contaminated water.
However, the low-dose impact on frogs may indicate risk to the
development of human sex hormones and characteristics, as well.
- Joseph M. Kiesecker, a biologist at Penn State University,
and other reported in July that deformities in frogs were increased
when the amphibians suffered damaged immune systems caused by
pesticide exposure. Tested were atrazine, malathion (used in households
and on farms) and Esfenvalerate, a synthetic pyrethroid appreciated
because it is thought be to fairly safe for birds and mammals.
The latter material class is highly toxic to many other kinds
of organisms, including the frogs he tested.
He conducted studies in the field where the frogs were living,
at times with deformity occurrence levels of 20 to 30 percent.
While a parasitic infection caused the deformities, the impact
was heightened by even very low levels of atrazine and the synthetic
For details: http://www.nsf.gov/od/lpa/news/02/pr0258.htm.
Also troubling for Liebhardt, who serves as research director at
The Institute, is a 1998 report that has brought many more researchers
to look at human developmental effects of pesticides. Anthropologist
E.A. Guillete of the University of Arizona found profound and pervasive
differences in two groups of Mexican children with similar genetics
and culture, but different exposure to pesticides. She documented
dramatic differences in short-term memory, hand-eye coordination
and stamina, as well as a striking difference in the ability to
draw a person.
Her work, its impact in the scientific community and action it
spawned in a Canadian municipality, can be seen in the new video
release “Playing with Poison.” http://www.bullfrogfilms.com/catalog/play.html
Liebhardt is overseeing final data collection and analysis of the
Rodale soil water study.
Watch here for news of The Institute’s report in spring 2003,
with recommendations on practical ways that farmers and policy makers
can significantly reduce agricultural pesticide pollution. “It’s
like driving while intoxicated – we just can’t afford
it,” says Liebhardt of continued casual acceptance of pesticide
use now shown to harm wildlife and, quite probably, developing babies