Phát âm chuẩn cùng VOA – Anh ngữ đặc biệt: Building a Windbreak (VOA)

Published on 29/10/2014

Học tiếng Anh hiệu quả, nhanh chóng:, Nếu không vào được VOA, xin hãy vào để vượt tường lửa. Các chương trình học tiếng Anh miễn phí của VOA (VOA Learning English for Vietnamese) có thể giúp bạn cải tiến kỹ năng nghe và phát âm, hiểu rõ cấu trúc ngữ pháp, và sử dụng Anh ngữ một cách chính xác. Xem thêm:

Luyện nghe nói và học từ vựng tiếng Anh qua video. Xem các bài học kế tiếp:

Ag: Luyện nghe nói tiếng Anh qua video: Chương trình học tiếng Anh của VOA: Special English Agriculture Report. Xin hãy vào để xem các bài kế tiếp.

Soil conservation methods help farmers protect their land from the damage caused by farming and the forces of nature. One method 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 help prevent the loss of soil. They stop the wind from blowing soil away. They also keep the wind from damaging or destroying crops. Windbreaks can be highly valuable for protecting grain crops. For example, studies have been done on windbreaks in parts of West Africa. These studies found that grain harvests were as much as twenty percent higher in fields protected by windbreaks compared to fields without them. But here is something interesting about windbreaks. They seem to work best when they permit some wind to pass through the barrier of trees or plants around a field. If not, then the movement of air close to the ground will lift the soil. Then the soil will be blown away. For this reason, a windbreak works best if it contains only sixty to eighty percent of the trees and plants that would be 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 or other plants with leaves. Locally grown trees and plants are considered the best choices for windbreaks.

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