Can Genetically Modified Crops Feed the World?
Humans have been genetically modifying crops for millenia the old-fashioned way—selective breeding. But new techniques that insert foreign genetic material, say bacterial genes to produce insecticide in a corn plant, have raised health and environmental concerns. And that has prompted European countries, most recently Germany, to ban genetically modified, or GM, crops.
Proponents argue that GM crops can help feed the world. And given ever increasing demands for food, animal feed, fiber and now even biofuels, the world needs all the help it can get.
Unfortunately, it looks like GM corn and soybeans won't help, after all.
A study from the Union of Concerned Scientists shows that genetically engineered crops do not produce larger harvests. Crop yield increases in recent years have almost entirely been due to improved farming or traditional plant breeding, despite more than 3,000 field trials of GM crops.
Of course, farmers have typically planted, say, GM corn, because it can tolerate high doses of weed-killer. And the Biotechnology Industry Organization argues that GM crops can boost yields in developing countries where there are limited resources for pesticides.
But it appears that, to date, traditional plant breeding boosts crop yields better than genetic modification. Those old farmers were on to something.
轉(zhuǎn)基因農(nóng)作物能給世界提供足夠多的糧食嗎?
人類以選擇性培育的傳統(tǒng)方式對農(nóng)作物進行基因改良已經(jīng)有幾千年歷史了。新的轉(zhuǎn)基因技術(shù)能把外界的基因物質(zhì),比如細菌基因植入到玉米中,從而產(chǎn)生殺蟲劑。這種方式引起了健康和環(huán)境方面的關(guān)注。這促使歐洲國家——最近主要是德國——禁止轉(zhuǎn)基因農(nóng)作物(GM)。
支持者稱轉(zhuǎn)基因農(nóng)作物能幫助解決世界糧食問題。考慮到世界對食物、動物飼料以及生物燃料日益增加的需求,這個世界需要所有它能得到的一切幫助。
不幸的是,好像轉(zhuǎn)基因的玉米和大豆根本就起不到作用。
來自“擔憂的科學家聯(lián)盟”(Union of Concerned Scientists)的一份研究表明,轉(zhuǎn)基因農(nóng)作物不能獲得更高的產(chǎn)量。雖然對轉(zhuǎn)基因農(nóng)作物進行了3000多次的室外試驗,但是近幾年農(nóng)作物產(chǎn)量的提高大部分完全是歸因于改進的農(nóng)業(yè)技術(shù)或者傳統(tǒng)的植物培育。
當然,農(nóng)場主們也經(jīng)常種植一些轉(zhuǎn)基因的農(nóng)作物,比如玉米,因為這些農(nóng)作物耐得住高劑量的除草劑。“生物科技工業(yè)組織” (Biotechnology Industry Organization)稱轉(zhuǎn)基因農(nóng)作物在缺乏殺蟲劑的發(fā)展中國家能提高產(chǎn)量。
但是到目前為止,似乎傳統(tǒng)的植物培育技術(shù)比轉(zhuǎn)基因技術(shù)更能提高農(nóng)作物產(chǎn)量。還是那些農(nóng)場主老手們有解決問題的辦法。
Vocabulary:
Millennium: 千年,復(fù)數(shù)為Millennia
Breed: 繁殖
Insecticide: 殺蟲劑
Proponent: 支持者
Tolerate: 忍受
Boost: 提高
Pesticide: 殺蟲劑