2004-11-29
I'm Gwen Outen with the VOA Special English Agriculture Report.
Farmers use different kinds of soil conservation methods to
protect their land from damage by farming and the forces of nature.
One important form of soil conservation is the use of windbreaks.
Windbreaks are barriers formed by trees and other plants with
many leaves. Farmers plant them in lines around their fields.
Windbreaks stop the wind from blowing soil away. They also keep
the wind from destroying or damaging crops. They are very important
for growing grains, such as wheat.
There have been studies done on windbreaks in parts of West
Africa, for example. These found that grain harvests can be twenty
percent higher in fields protected by windbreaks compared to fields
without such protection.
However, windbreaks seem to work best when they allow a little
wind to pass through. If the wall of trees and plants stops wind
completely, then violent air motions will take place close to the
ground. These motions cause the soil to lift up into the air where
it will be blown away.
For this reason, a windbreak is best if it has only sixty to
eighty percent of the trees and plants needed to make a solid line.
An easy rule to remember is that windbreaks can protect areas up
to ten times the height of the tallest trees in the windbreak.
There should be at least two lines in each windbreak. One line
should be large trees. The second line, right next to it, can be
shorter trees and other plants with leaves. Locally grown trees and
plants are best for windbreaks.
Windbreaks not only protect land and crops from the wind. They
can also provide wood products. These include wood for fuel and
longer pieces for making fences.
You can get more information about windbreaks and other forms of
soil conservation from the group Volunteers in Technical Assistance.
VITA is an organization that helps people around the world use
science and technology to solve problems. VITA is on the Web at
vita.org.
You can find more Agriculture Reports at voaspecialenglish dot
com. If you have a question for us, send it to special@voanews.com.
Make sure to include your name and where you live. We might be able
to answer your question on the air. But please know that we cannot
answer questions personally.
This VOA Special Agriculture Report was written by Gary Garriott.
This is Gwen Outen.