This is the VOA SpecialEnglish Agriculture Report.
Soil conservation efforts protect soil from wind and water thatcan blow or wash it away. Good soil produces food crops for bothpeople and animals.
One important form of soil conservation is the use of windbreaks.Windbreaks are barriers formed by trees and other plants with manyleaves. Farmers plant them in lines around their fields. Windbreaksstop the wind from blowing soil away. They also keep the wind fromdestroying or damaging crops. They are very important for growinggrains, such as wheat.
For example, in parts of WestAfrica, studies have shown that grain harvests can be twenty percent higher on fields protected by windbreaks compared to thosewithout such protection.
Windbreaks are effective when a wall of trees and other plantsblocks the wind. The windbreaks should also limit violent motions ofthe wind to those areas closest to the windbreak.
However, windbreaks seem to work best when they allow a littlewind to pass through. If the wall of trees and plants stops windcompletely, then violent air motions will take place close to theground. These motions cause the soil to lift up into the air whereit will be blown away. For this reason, a windbreak is best if ithas only sixty to eighty per cent of the trees and plants needed tomake a solid line.
An easy rule to remember is that windbreaks can protect areas upto ten times the height of the tallest trees in the windbreak.
There should be at least two lines in each windbreak. One lineshould be large trees. The second line, right next to it, can beshorter trees and other plants with leaves.
Windbreaks not only protect land and crops from the wind. Theycan also provide wood products. These include wood for fuel andlonger pieces for making fences. Locally grown trees and plants arebest for windbreaks.
You can get more information about windbreaks and other forms ofsoil conservation from the group Volunteers in Technical Assistance.VITA is an organization that helps people around the world usescience and technology to solve problems.
You can contact VITA through the Internet at its World Wide Webaddress, w-w-w dot v-i-t-a dot o-r-g.
This Agriculture Report was written by Gary Garriott.