Toxicity of Chemicals Depends on Soil
Joe Stucki, 217-333-9636, email@example.com,
Source: Gary Beaumont, 217-333-9440, firstname.lastname@example.org
It was thought that as farm chemicals start degrading in contact
with soil they become less toxic, but new research from the University
of Illinois, published in the August 15, 2004 issue of Environmental
Science & Technology, suggests that certain pesticide
can actually become more toxic in contact with reduced, iron-bearing
clays commonly found in soils.
The long held theory was that farm chemicals became less harmful
in the soil through a process of microbial degradation and sequestration.
No one expected, therefore, to discover a chemical reaction with
clay particles that increased the toxicity of a compound. "We
expected to see some reaction because other studies we have done
showed that reduced clay is more reactive than oxidized clay,"
said Joe Stucki, University of Illinois professor of soil chemistry.
"But we were surprised that the toxicity of one of the compounds
The researchers in this project mixed four different herbicides
with reduced or unoxidized ferruginous smectite, a specific group
of clay minerals. They compared the toxicity of the pesticide
on its own to the toxicity of the pesticide that had reacted with
the smectite. They used a widely accepted toxicity test employing
mammalian cells of a hamster.
Treatment with reduced smectite, or clay mineral with little
or no oxygen attached to it, substantially increased the toxicity
of dicamba by as much as 33 percent, decreased the toxicity of
oxamyl by 50 percent, slightly decreased the toxicity of alachlor,
and for 2,4-D toxicity remained about the same.
Dicamba is one of the most widely used products for controlling
broadleaf weeds in corn. Oxamyl is widely used for control of
insects, mites and nematodes on field crops, fruits and ornamentals.
The majority of oxamyl is applied to apples, potatoes, and tomatoes.
Alachlor is a herbicide for control of annual grasses and broadleaf
weeds in crops, primarily on corn, sorghum and soybeans. Alachlor
is the second most widely used herbicide in the United States,
with particularly heavy use on corn and soybeans in Illinois,
Indiana, Iowa, Minnesota, Nebraska, Ohio, and Wisconsin.
2,4-D is a herbicide for the control of broad-leaf weeds in agriculture,
and for control of woody plants along roadsides, railways, and
utilities rights of way. It has been most widely used on such
crops as wheat and corn, and on pasture and rangelands.
"Virtually every study looking at the effect of soil and
clay minerals on the fate of pesticides has ignored oxidization
state. That's an omission because soils are commonly in a reduced
condition and now we have shown that the oxidation state makes
a big difference," said Stucki. "What we're showing
here, at least in the case of dicamba, is that the compound became
more toxic when it came into contact with the reduced clay, so
we can't always assume that when a compound comes into contact
with the soil it’s a positive environmental outcome,"
The pesticide levels tested were comparable to pesticide concentrations
commonly found on farms. Also, smectite clays are abundant in
many soil profiles. Reduced smectite clay particles are often
found near the soil surface due to rainfall events and microbial
activity. Stucki says other degradation products were found in
the research and the research team is currently attempting to
identify those compounds and measure their toxicity.
The research was part of a dissertation project of Kara Sorensen,
who now works for the Naval Research Laboratory in San Diego.
Her initial interest grew out of a desire to study cancer in wildlife
and what might cause it. Funding came, in part, from the Department
of Energy, National Science Foundation, U.S. Israel Bi-National
Agricultural Research Fund, International Arid Lands Consortium,
and the U of I Agricultural Experiment Station.
Penn State Evaluating European Haydryer
Glen Cauffman, 814-865-4433, email@example.com,
Author: Jeff Mulhollem, 814,863-2719, firstname.lastname@example.org
In an ironic twist of technology that has Penn State farm operations
manager Glen Cauffman feeling like a bit player in the hit movie
"Back to The Future," the College of Agricultural Sciences
is evaluating a new European spin on a 50-year-old hay-drying
process that has major implications for Pennsylvania farmers.
That the evaluation is coming in a very wet summer is another
quirk of fate. "In the 1950s and '60s, it was common for
Pennsylvania farmers to use haydryers," Cauffman explained
recently, while watching a demonstration of the haydryer made
by Feribale Manufacturing, an Italian forage equipment maker,
at Penn State's Ag Progress Days. "But they disappeared in
the United States. "Haydryers made economic sense when diesel
fuel was selling for 2 cents a gallon," Cauffman added, "but
not when it rose to 80 cents a gallon. The last one I remember
was a New Holland model that went out of production in the 1960s."
Cauffman estimates that 100 or so haydryers are in use in Europe.
Penn State is doing the only evaluation of a haydryer in this
country, an arrangement resulting from a representative of the
Italian forage equipment maker approaching Cauffman about giving
the machine a try. "I was skeptical at first," he admits.
"But it looks like advances in energy efficiency make the
haydryer a possibility for Pennsylvania farmers. We have been
evaluating the machine since May, and the results are not yet
in, but it looks like it offers some distinct advantages."
The theory behind a haydryer, which can be fueled by fuel oil,
natural gas or propane, is that after farmers cut hay and allow
it to partially dry in the field, and before it reaches a moisture
level safe to store in a barn, the hay is put into a haydryer
for six or seven hours. The resulting forage, because it was dried
relatively quickly and soon after it was cut, retains a higher
nutritional value for livestock. "I think this machine will
interest a lot of Pennsylvania farmers," Cauffman says. "A
big advantage is that the more hay dries in the field, the more
leaves it loses. So the advantage of baling it at a higher moisture
level is that it retains more leaves and more nutritional value.
And in theory, that higher nutritional value will pay for the
drying costs. The jury is still out on that, however, and that
is what we are evaluating here at Penn State."
According to Cauffman, having a haydryer has been a particular
blessing during this rainy summer, which has been one of Pennsylvania's
wettest ever. "We haven't had many three-consecutive-dry-day
periods that we need to dry hay in the field before bringing it
in," he says. "We were able to partially dry hay in
the field and finish it in the haydryer. Without it, we'd have
lost a lot of hay. And last fall, we were able to make hay clear
into November with it, and we never could do that before."
Further Testing and Simulation of Hay Bale Loading on Semi-Trailers
Robert Di Cristoforo and Dr Peter F Sweatman, Roaduser Systems
Pty Ltd, July 2004, RIRDC Publication No 04/124 RIRDC Project
The study aimed to provide a sound technical basis to aid State
jurisdictions in developing consistent hay bale loading rules
which are more clearly related to safety objectives. There was
a need to address the effects of load dimensions on both vehicle
stability and road width requirements; these two vehicle performance
measures are effectively controlled by PBS, which allows flexibility
in vehicle regulation by exempting vehicles from prescriptive
regulations without adversely affecting safety.
The assessment covered the four common hay bale sizes (nominally
expressed as 3’x3’x8’ rectangular, 4’x3’x8’
rectangular, 4’x4’x8’ rectangular and 5’x4’
round), along with the common stacking arrangements employed by
industry, a variety of load restraint methods and a set of representative
hay truck configurations, providing a total of 77 combinations.
The assessment process  included two parts. Firstly, each load
type was physically tested in a specially designed rig to determine
its lateral rigidity when properly restrained on a trailer deck.
The load types included all bale sizes, stacking arrangements
and load restraint methods for a total of 31 test set-ups.
Lateral rigidity characteristics were recorded as force-displacement
plots that were used in further analysis. Secondly, the stability
and road width requirements were determined for each vehicle configuration
and load type by computer simulation of vehicle dynamics. The
lateral rigidity parameters obtained from the tests were incorporated
into the models to pass the effect of load movement on to roll
stability performance. These simulation models provided valuable
information regarding the effect of load height and bale type
on stability, with effects due to load restraint methods also
The physical tests revealed enormous variations in lateral rigidity
between the different types of bales, with round bales offering
the least rigidity. The 4’x4’x8’ rectangular
bales were by far the best performers, with more than twice the
rigidity of round bales at 4.6m high. The computer simulation
models predicted considerable variation in rollover stability.
The biggest contributing factor was bale type, followed by stacking
arrangement, vehicle configuration and finally load restraint
Wind Power’s Contribution to Electric Power Generation
and Impact on Farms and Rural Communities
A Government Accountability Office report found that while wind
power does not contribute significantly to total farm income in
the 10 states with the highest installed wind power capacity,
it has great benefit for some farmers and rural communities. The
report, states that a farmer who leases land for a wind project
can expect to receive $2,000 to $5,000 per turbine per year in
lease payments. The study found that most of the nations wind
potential remains untapped, accounting for only about one-tenth
of one percent of total U.S. electric power generation capacity
in 2003. Wind power’s growth will depend largely on the
continued availability of federal and state financial incentives,
including tax credits, and expected increases in prices for fossil