chemicals, fertilizers, herbicides, and insecticides have definite
benefits. But they can also create serious water quality problems.
Explore more about the relationship between these chemicals and
land-applied chemical has a specific purpose. Fertilizers provide
nutrients to enhance plant growth. Theyre used on crops, on
gardens, on lawns and golf coursesany place you want plants
are two nutrients common to .
Herbicides and pesticides have a much different purpose. Theyre
used to kill weeds or insects that interfere with the plants youre
trying to grow, like corn or flowers. To get the desired results
and avoid water quality problems, these chemicals must be applied
correctly. Properly applied chemicals stay on the land and out of
water, where they can seriously damage aquatic environments.
do the chemicals get into water? One answer is
. Runoff is
part of the hydrologic cycle. Water, usually from precipitation,
moves across landscapes and eventually winds its way to streams
and rivers. If runoff moves across land where chemicals were applied,
the chemicals can be swept up into the cycle. If the chemicals are
not trapped before they reach streams and rivers, they can cause
happens when these chemicals get into water? When fertilizers are
swept into waterways by runoff, they provide nutrients to aquatic
plants, increasing their growth. This increased growth can trigger
a dramatic chain of events for aquatic ecosystems. Excess nitrogen
in drinking water poses a serious health threat to pregnant women
and babies. High concentrations of other chemicals, like herbicides
or pesticides, can kill aquatic plants and animals as well as posing
a health risk to people.
chemicals need to be managed very carefully, but the risk is especially
high on farms where chemicals are kept in large volume. Huge spills
are catastrophic to waterways and the plants and animals living
there. In Iowa, some of the states worst were caused
by big chemical spills.
Because there are risks associated with using land-applied chemicals,
should their use be controlled? There are some regulations in place
for farmers, but not many. Should there be more? How would they
be enforced? How about for homeowners?
All in the
What should you consider when applying chemicals to a landscape?
conditions What are the existing nutrient levels? (the
quantity of nitrogen and phosphorous in the soil)
precipitation Are you applying right before a rain?
This increases the chances of ?
of year will the plants use the nutrients now or will
they be stored in the soil?
- Are you
applying an appropriate product? an appropriate amount?
- Are there
waterbodies nearby that could be contaminated if the chemicals
and Chemical Application
farmers consistently produce enough crops and livestock to feed
not only our nation, but also to send food to nations around the
does it take to achieve a lush lawn? A perfectly manicured ballpark?
A rolling green golf course? Many times it takes chemicals. More
expected benefit of genetically engineered crops is the reduced
need for pesticides and herbicides. More
and the Dead Zone
Doyle family farms along the Mississippi River in Iowa. Their corn
and soybean crops grow in rich river soil, created by centuries
of sediment deposited by glaciers and the Mississippi's flood cycles.
Management Practices (BMPs) are suggestions to landowners on how
they can continue to use their land while maintaining the environment.
all lawn care products contain harmful chemicals. In 1986, Nick
Christians, an Iowa State University horticulture professor, discovered
that corn gluten kills dandelions and other weeds. More
to Market Links
source pollution targeted by EPA
According to the environmental protection agency, or e-p-a, there
are more than 20,000 u.s. lakes, streams and rivers that fail to
meet current water quality standards, as defined by the clean water
act of 1972.