You cannot see this page without javascript.


This is the VOA Special English Agriculture Reportt, from http://voaspecialenglish.com | http://facebook.com/voalearningenglish


Organic farming avoids the use of chemical pesticides and manmade fertilizers. Supporters say organic farming is better for the environment than other methods. But studies have shown that organic farming often produces less food per hectare. That lower yield means feeding the world organically would require more land. But good farmland is limited. And scientists say deforestation from the clearing of land for agriculture is already a problem for climate change. In a new study, researchers wanted to measure the difference between conventional and organic yields. So they combined the results of sixty-six earlier studies. They found that some organic farms can yield almost as much as conventional farms. But most cannot. The findings were reported in the journal Nature. The study's lead author was Verena Seufert of McGill University in Canada. She says convention farms usually have higher yields than organic ones. But some activities, environmental conditions and even crops can narrow the differences. On average, organic farms produced twenty-five percent less compared to conventional farms. But yields of organic fruits and other perennial crops nearly equaled the yields from conventional ones. So did the yields of legumes such as soybeans. Legumes produce some of their own nitrogen fertilizer. However, organic vegetables and cereal crops had a lot lower yields compared to conventionally grown crops. Ms. Seufert says the soil on organic farms holds water better, and that can reduce the yield difference. Also, organic farmers can improve their yields by making sure crops get enough fertilizer. But increasing the nitrogen is harder to do organically, using just animal waste and crop rotations. Organic farmers rotate food crops with plants that fertilize the soil. But while these "cover," or fertilizer, crops are growing, food crops have to be grown on other land. And if farmers use manure, they have to feed the animals that produce it, and that requires grazing land or crop land. The United Nations says world demand for food will grow seventy percent by the middle of the century. John Reganold is a scientist at Washington State University. He says no one should dismiss organic agriculture as part of the solution. He says farming is increasingly a mix of organic and conventional methods. For VOA Special English, I'm Alex Villarreal.(Adapted from a radio program broadcast 01May2012)

원문출처 : http://www.youtube.com/watch?v=XYY-pp0cFbQ&feature=youtube_gdata

profile
엮인글 :
List of Articles
번호 제목 글쓴이 날짜 조회 수
265 굿모닝팝스 2012/06/02 (토) 이근철의 굿모닝팝스 chanyi 2012-06-02 411
264 굿모닝팝스 2012/06/01 (금) 이근철의 굿모닝팝스 chanyi 2012-06-01 386
263 CNN Fighting in Syria; Michael Bloomberg Wants to Ban Large Sodas chanyi 2012-06-01 1066
262 굿모닝팝스 2012/05/31 (목) 이근철의 굿모닝팝스 chanyi 2012-05-31 375
261 CNN Charles Taylor Sentenced to 50 Years chanyi 2012-05-31 844
260 굿모닝팝스 2012/05/30 (수) 이근철의 굿모닝팝스 chanyi 2012-05-30 377
259 CNN Rescue Workers Search for Survivors After Earthquake in Italy chanyi 2012-05-30 739
258 굿모닝팝스 2012/05/29 (화) 이근철의 굿모닝팝스 chanyi 2012-05-29 359
257 CNN Observing Memorial Day; Tracking Tropical Storm Beryl chanyi 2012-05-29 586
256 VOA News Language Has Risks for Health Translators chanyi 2012-05-29 885
255 VOA News Teens Get a History Lesson From History Makers chanyi 2012-05-29 600
254 VOA News 'FlashFood' App Wins US Finals in Imagine Cup for Students chanyi 2012-05-29 435
» VOA News The Limits to Organic Farming in Feeding the World chanyi 2012-05-29 468
252 VOA News US-China Meeting Starts With Call for Fair Exchange Rate chanyi 2012-05-29 545
251 굿모닝팝스 2012/05/28 (월) 이근철의 굿모닝팝스 chanyi 2012-05-28 438
250 굿모닝팝스 2012/05/27 (일) 이근철의 굿모닝팝스 chanyi 2012-05-27 418
249 굿모닝팝스 2012/05/26 (토) 이근철의 굿모닝팝스 chanyi 2012-05-26 288
248 굿모닝팝스 2012/05/25 (금) 이근철의 굿모닝팝스 chanyi 2012-05-25 521
247 CNN CNN Student News Transcript - May 25, 2012 chanyi 2012-05-25 468
246 굿모닝팝스 2012/05/24 (목) 이근철의 굿모닝팝스 chanyi 2012-05-24 437
본 사이트에서는 회원분들의 게시된 이메일 주소가 무단으로 수집되는 것을 거부합니다. 게시된 정보 및 게시물의 저작권과 기타 법적 책임은 자료제공자에게 있습니다. 이메일:chanyi@hanmail.net Copyright © 2001 - 2022 EnjoyEnglish.co.kr. All Right Reserved.
커뮤니티학생의방교사의 방일반영어진로와 진학영어회화