Organic 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 waters.
“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 Trial (CUT).
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.
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
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 Foundation. http://www.nsf.gov/od/lpa/news/02/pr0226.htm.
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,
- 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 pyrethroid.
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.”
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 as well.