This is the VOA Special English Agriculture Report.
Planting trees around poultry farms can
improve air and water quality -- and relations with neighbors. Research has shown
that just three rows of trees near poultry houses can reduce the release of
dust and ammonia. They can also reduce the strong smell of ammonia gas.
The trees capture dust, ammonia and odors in their
leaves. They also provide shade from the sun, so they reduce cooling costs in
summer. And they act as a windbreak, so they reduce heating costs in winter. Trees
can also improve water quality around farms by removing pollutants from soil
years ago, people were objecting to the odor of poultry farms on the Delmarva
Peninsula in the eastern United States. Delmarva is where the states of
Delaware, Maryland and Virginia come together. Two thousand farms there can each
house an average of seventy-five thousand chickens.
the farms used windows to provide fresh air in the chicken houses. Farmers
rarely planted trees or tall crops around the buildings, so there would be no
barrier to the airflow.
But then farms began to use new
ventilation systems. Instead of windows, the new systems used tunnel fans to
circulate air. The fans directed airflow from the poultry houses toward the
homes of neighbors.
Researchers led by George Malone at the University of
Delaware began dealing with the problem in two thousand. They found that over a
period of six years, planting three rows of trees reduced total dust and
ammonia by more than half. And they found that odors were reduced by eighteen
scientists reported their findings in two thousand eight at a meeting of the
American Chemical Society.
For the first row nearest the fans, they generally
suggested trees that lose their leaves in the fall or trees with waxy leaf
surfaces. They suggested evergreen trees for the other two rows. Some trees
work better than others. And what works in one area of the country may not work
as well in others.
may think trees will take too long to grow and be effective. But some trees can
At least one-third of the Delmarva farms
have planted trees, technically known as vegetative environmental buffers. The
idea offers a way to cut pollution, save money and energy, and make the
And that's the VOA Special English
Agriculture Report, written by Jerilyn Watson. I'm Steve Ember.