官方APP下载:英语全能特训(微信小程序版,支持苹果手机、安卓手机)
创办于2003年
UNSV记不住?那就记中文谐音“忧安思危”吧!
  Slow and Steady Wins the Race!
UNSV英语学习频道 - Slow and steady wins the race!

英语全能特训(微信小程序)
UNSV英语学习频道淘宝网店
客服短信:18913948480
客服邮箱:web@unsv.com
初级VIP会员
全站英语学习资料下载。
¥98元/12个月

AGRICULTURE REPORT - Ideas for Getting a Firm Grip on Weed Control

阅读次数:


VIP会员专享下载:(非VIP会员无权下载!如果想下载,但还不是VIP会员,请点此订购
下载方式:使用鼠标右键(注意是鼠标右键!)点击下面的MP3音频/MP4视频链接,然后选择“另存为…”。
英汉翻译对照 英汉翻译对照  MP3节目录音 MP3节目录音  PDF节目文稿 PDF节目文稿  MP3同步字幕 MP3同步字幕 
文章正文
同步字幕
Bessie Tsimba, who is originally from Zimbabwe, weeds around her onion beds in Dracut, Massachusetts
Bessie Tsimba, who is originally from Zimbabwe, weeds around her onion beds in Dracut, Massachusetts

This is the VOA Special English Agriculture Report.

When is a plant considered a weed? Experts at Penn State University have a simple answer: When the undesirable qualities outweigh the good qualities.

Consider that crops generally produce several hundred seeds from each plant. By comparison, each weed plant can produce tens or even hundreds of thousands of seeds. And some buried seeds can survive up to forty years -- or even longer.

Eradicating weeds means that you have to remove all the seeds and roots so the plants will not grow back. But birds or the wind can reintroduce them to the land.

A more common way to deal with weeds is to control them enough so that the land can be used for planting. Experts advise using two or more control methods to deal with weeds.

Chemical weed killers or natural treatments like corn gluten can suppress weed growth. Dense planting of a crop can also act as a natural control.

Bill Curran at Penn State in University Park, Pennsylvania, is a professor of weed science. He says one of the most common methods for suppressing weeds is dense planting.

He says a dense, competitive crop that quickly shades the soil will help suppress many weeds. The seeds need light to grow, so blocking the sun will reduce weed growth.

Other controls include turning over the soil, pulling the weeds or covering them with mulch made of wood, garden waste or other material.

But even mulch has its limits. Natural resource specialists point out that weeds can be transported in mulch. This is also true of soil, grain, hay and animals.

Yet animals like sheep or goats eat weeds, so they can provide a biological control. Insects and other organisms can also act as biological controls.

Preventing the spread of weeds is an important part of weed management. Farm vehicles should be kept out of areas with weeds. If that is not possible, then clean off the equipment and your shoes when leaving.

Some people burn weeds or bury them deeply or make them into mulch.

Professor Curran says another way to make use of weeds is to compost them. The process of making organically rich compost produces heat. The heat will kill many, though not all, weed seeds. The same is true of seeds that pass through animals that graze on weeds.

And that's the VOA Special English Agriculture Report, written by Jerilyn Watson. Tell us about your own struggle against weeds. You can post comments at www.unsv.com or on Facebook or Twitter at VOA Learning English. I'm Jim Tedder.

网友的学习评论(0条):
版权所有©2003-2019 南京通享科技有限公司,保留所有权利。未经书面许可,严禁转载本站内容,违者追究法律责任。 互联网经营ICP证:苏B2-20120186
网站备案:苏ICP备05000269号-1中国工业和信息化部网站备案查询
广播台