VOA标准英语2010-Report Cites Biotech Crop Benefits

Advantages threatened by poor management

Steve Baragona | Washington, DC 15 April 2010

No-till agriculture is one of the benefits of GE crops that is threatened by poor management

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National Research Council report

Genetically¹ engineered crops have had a positive impact on the environment and on many farmers' profits, according to a new report by the U.S. National Research Council. But the report says poor management threatens some of those benefits.

Nearly half of the farmland in the United States is planted with crops that have been genetically engineered, mainly maize², soybeans and cotton.

There are two major traits among these GE crops: resistance to certain insect pests, and resistance to a weed-killer called glyphosate. The new report looked at research comparing the environmental impact of GE crops to conventional crops.

"In general, we find that genetically engineered crops have had fewer adverse³ effects on the environment than non-GE crops produced conventionally," says report co-author LaReesa Wolfenbarger, a biology professor at the University of Nebraska. 

Fewer chemicals, less tillage

Wolfenbarger says insect-resistant⁴ GE crops have fewer adverse effects because farmers don't have to spray as many toxic⁵ insecticides. And farmers planting glyphosate-resistant crops can use just one less-toxic herbicide to control weeds. And they often don't have to till at all, which is better for the soil.

And many farmers growing GE crops have seen economic benefits like higher yields, lower costs, and more flexibility⁶ than their conventional-farming counterparts.

Weeds strike back

However, farmers have relied so heavily on glyphosate that at least eight species of weeds are now resistant to it. Ervin says that means some farmers have returned to using soil-disturbing tillage or more toxic herbicides to control weeds.

"We really need to get after this weed resistance problem right away before we lose the efficacy of that technology," says report committee chair David Ervin of Portland State University. "There's just too much at stake to lose that, economically, environmentally, and perhaps even socially."

That's a view shared by Gregory Jaffe at the consumer group, the Center for Science in the Public Interest.

"The report reconfirms that we still need a strong regulatory system to ensure that the technology is not squandered⁷ away by poor management practices by both farmers and seed developers," Jaffe says.

Big questions remain

The report was intended to assess the environmental, economic, and social impact of GE crops on farm sustainability in the United States.

But, Ervin says, "We could not complete that assessment⁸ at this point because we don't have sufficient evidence."

For example, the report says the widespread adoption⁹ of no-till agriculture by farmers using glyphosate-resistant crops should reduce soil erosion, which is the largest source of water pollution in the United States. But there is no mechanism¹⁰ to track these effects.

The report also notes a lack of research on the economic impacts of widespread adoption of GE crops on the livestock¹¹ industry, which is their biggest consumer, or on farmers who do not grow GE crops.

Non-GE organic crops can often fetch a premium¹² price. But Bob Scowcroft, director of the Organic Farming Research Foundation, says in four surveys over the past decade, "We've documented organic farmers that have lost their [organic] certification because of GE contamination" from neighboring farmers' crops.

The report calls for more resources to study these important questions so farmers, seed developers, and policymakers can make better decisions.
 

1 genetically   

adv.遗传上

参考例句：

• All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
• Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物

2 maize   

n.玉米

参考例句：

• There's a field planted with maize behind the house.房子后面有一块玉米地。
• We can grow sorghum or maize on this plot.这块地可以种高粱或玉米。

3 adverse   

adj.不利的；有害的；敌对的，不友好的

参考例句：

• He is adverse to going abroad.他反对出国。
• The improper use of medicine could lead to severe adverse reactions.用药不当会产生严重的不良反应。

4 resistant   

adj.(to)抵抗的，有抵抗力的

参考例句：

• Many pests are resistant to the insecticide.许多害虫对这种杀虫剂有抵抗力。
• They imposed their government by force on the resistant population.他们以武力把自己的统治强加在持反抗态度的人民头上。

5 toxic   

adj.有毒的，因中毒引起的

参考例句：

• The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
• There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。

6 flexibility   

n.柔韧性，弹性，（光的）折射性，灵活性

参考例句：

• Her great strength lies in her flexibility.她的优势在于她灵活变通。
• The flexibility of a man's muscles will lessen as he becomes old.人老了肌肉的柔韧性将降低。

7 squandered   

v.（指钱，财产等）浪费，乱花( squander的过去式和过去分词 )

参考例句：

• He squandered all his money on gambling. 他把自己所有的钱都糟蹋在赌博上了。
• She felt as indignant as if her own money had been squandered. 她心里十分生气，好像是她自己的钱给浪费掉了似的。 来自飘（部分）

8 assessment   

n.评价；评估；对财产的估价，被估定的金额

参考例句：

• This is a very perceptive assessment of the situation.这是一个对该情况的极富洞察力的评价。
• What is your assessment of the situation?你对时局的看法如何？

9 adoption   

n.采用，采纳，通过；收养

参考例句：

• An adoption agency had sent the boys to two different families.一个收养机构把他们送给两个不同的家庭。
• The adoption of this policy would relieve them of a tremendous burden.采取这一政策会给他们解除一个巨大的负担。

10 mechanism   

n.机械装置；机构，结构

参考例句：

• The bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人体的组成部件。
• The mechanism of the machine is very complicated.这台机器的结构是非常复杂的。

11 livestock   

n.家畜，牲畜

参考例句：

• Both men and livestock are flourishing.人畜两旺。
• The heavy rains and flooding killed scores of livestock.暴雨和大水淹死了许多牲口。

12 premium   

n.加付款；赠品；adj.高级的；售价高的

参考例句：

• You have to pay a premium for express delivery.寄快递你得付额外费用。
• Fresh water was at a premium after the reservoir was contaminated.在水库被污染之后，清水便因稀而贵了。