VOA慢速英语-Agriculture Report - Building a Windbreak to Protect

Barriers of trees and other plants seem to work best when they let a little wind pass through. Transcript¹ of radio broadcast:
28 July 2008

This is the VOA Special English Agriculture Report.
　

A windbreak

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. Farmers plant these barriers 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 protecting grain crops.

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.

But windbreaks seem to work best when they allow some winds to pass through them. If the wall of trees and plants blocks the wind completely, then violent air motions² will take place close to the ground. These motions will lift soil 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.

If the quality of the land is not very good, studies have shown that one kind of tree that can grow well is the white pine. Another is the loblolly pine.

Windbreaks not only protect land and crops from the wind. Surplus³ trees can be cut down and used to provide wood.

Trees reduce the damaging effects of wind and rain. Their roots help protect soil from being washed away. And trees do something else -- they can provide grazing⁴ animals with shade from the sun.

And that's the VOA Special Agriculture Report. You can get more information about windbreaks and other forms of soil conservation at enterpriseworks.org. And you can also learn more about agriculture at our Web site, voaspecialenglish.com. I'm Jim Tedder⁵.

1 transcript   

n.抄本，誊本，副本，肄业证书

参考例句：

• A transcript of the tapes was presented as evidence in court.一份录音带的文字本作为证据被呈交法庭。
• They wouldn't let me have a transcript of the interview.他们拒绝给我一份采访的文字整理稿。

2 motions   

n.（物体的）运动( motion的名词复数 )；提议；通便

参考例句：

• She just went through the motions of being a poetess. 她只不过装成一个女诗人。 来自《简明英汉词典》
• He always accompanied his speech with motions. 他讲演时总是伴以手势。 来自《简明英汉词典》

3 surplus   

adj.过剩的，多余的；n.过剩，剩余额

参考例句：

• The manufacturers in some countries dumped their surplus commodities abroad.一些国家的制造商向国外倾销过剩产品。
• The surplus steam was blown off through the pipes.多余的蒸气通过管道放掉了。

4 grazing   

n. 放牧, 牧草 动词graze的现在分词

参考例句：

• There were cows grazing beside the river. 有些牛在河边吃草。
• Cows were grazing on the marshes. 牛群在湿地上吃草。

5 tedder   

n.（干草）翻晒者，翻晒机

参考例句：

• Jim Tedder has more. 吉姆？特德将给我们做更多的介绍。 来自互联网
• Jim Tedder tells us more. 吉姆？泰德给我们带来更详细的报道。 来自互联网