Page 3, December 1985
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"It's kind of embarrassing to be sitting here
after 40 years of nitrate problems and not be
able to say anything about it," she said.
Health concerns about nitrates are not confined
I to humans. Twenty to 30 percent of cattle owners
I have problems with nitrate poisoning of their
animals, said Paul Guyer, beef specialist with
j NlTs Cooperative Extension Service.
Guyer said that nitrates in water alone are
rarely a problem when the level is below 100
I ppm. Combined with high levels in feeds,
however, nitrates can cause abortions and death
S in livestock.
Nitrates can get into the groundwater from
many sources. At Glen Huebert's farm, the source
of the nitrate pollution can be traced to one place
the lagoon for hog manure just 1 50 feet from
the well.
Natural plant decay, animal and human wastes
and nitrogen fertilizers all can produce nitrates.
But human practices, not natural sources, cause
most nitrate pollution, said Beth Rowan, a
hydrogeologist with the state Department of
Environmental Control.
According to a 1984 DEC study of ground
water pollution, septic tanks and feedlots are the
major causes of "point-source" nitrate pollution.
In Elmwood, for example, nitrates in the town's
wells were traced to a barnyard on the east edge
of town.
Nitrate levels in the groundwater in south
eastern Nebraska vary widely among neighboring
wells. The DEC study found that point-source
pollution causes most of the nitrate contamina
tion in the area.
Along the Platte River valley, between Kearney
and Columbus, and in Rock and Holt Counties in
north-central Nebraska, nitrate levels in ground
water are high throughout the region.
In these two areas, the DEC study says,
applied nitrogen fertilizers are the source of
nitrate pollution.
Extensive use of fertilizers, combined with
irrigation, is the main cause of high nitrate levels
in groundwater, said Bill Lock, a legislative
research assistant
Ideally the fertilizer applied to crops would be
used by the growing plants and it would re-enter
the natural cycle. However, if the amount of
fertilizer applied is more than the plant can use,
rain or irrigation water can wash the fertilizer
into the ground below the plant's roots.
Then it is only a matter of time before the
nitrates are carried into the groundwater.
Nebraska's present system of farming depends
on the use of fertilizer. The problem of nitrate
pollution arises from the numbers of farmers
who use fertilizer, especially those who use too
much fertilizer, Lock said.
Until recently farmers assumed that if a little
fertilizer worked well, a lot would be even better,
said Gordon Kissel, executive director of the
Nebraska Association of Natural Resources
Districts. Often the cost of adding that "little bit
extra" is less than the possible loss of yields from
using too little fertilizer. And it is cheaper to put
on a lot at once, even if some is washed away,
David CreamerSower
than to apply lesser amounts several times.
Agricultural experts were of little help to
farmers who wanted to know how much fertilizer
to use. In 1983, the University of Nebraska
Lincoln agronomy department compared fertilizer
recommendations from different laboratories
for four test plots. Some recommendations called
for twice as much fertilizer as others.
In addition, farmers often get advice on
fertilizer application from their fertilizer supplier,
said Scott Moore, aide to state Sen. Rod Johnson
of Sutton. The supplier may have an interest in
heavier use, Moore said.
The rate of build-up in groundwater depends
on the type of soil and the groundwater level in
an area. The nitrates appearing in Nebraska wells
today may have been building up for 10 or 20
years, Rowan said.
The solutions to such nitrate pollution are
controversial. Once into the groundwater, experts
agree, nitrates are hard to get back out.
A common misconception about groundwater,
Rowan said, is that there is some pool of water
lying in an underground cavern. In a few states
that is true, but Nebraska doesn't have any
underground rivers or lakes. Instead, ground
water fills the spaces between the particles of
soil, sand or gravel or squeezes into cracks in the
bedrock.
It's basically "saturated earth," Lock ex
plained. Given enough time, said Gale Hutton, chief of
the DEC's water division, groundwater will clean
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