VOA慢速英语 2008 0506a

Agriculture Report - Using Charcoal¹ to Make Soil Into Black Gold
Scientists show a way to improve soil quality with ''biochar.'' Transcript² of radio broadcast:
05 May 2008

This is the VOA Special English Agriculture Report.
　

The dense3 Amazon rainforest near Manaus, Brazil

In South America, the fertile soil of the Amazon River basin in Brazil is known as "black gold." Scientists found that the secret to this rich soil was charcoal. Tribal⁴ people made it from animal bones and tree bark. They mixed the charcoal with the soil about one thousand five hundred years ago.

Now, scientists in the United States have done a modern demonstration⁵. They say charcoal fertilization offers a revolutionary way to improve soil quality for hundreds or even thousands of years.

Mingxin Guo and his team at Delaware State University heated tree leaves, corn stalks, small pieces of wood and poultry⁶ waste into "biochar." They reported their findings at a recent meeting of the American Chemical Society in New Orleans.

Biochar could be good news for farmers with poor soil and hungry populations to feed. Professor Guo says it could even help against global warming. Intensive farming and overuse of chemical fertilizer releases carbon dioxide into the atmosphere. Biochar does the opposite, he says: it traps carbon in the ground.

The researchers planted winter wheat in containers of soil in a greenhouse -- some with biochar, some without. Professor Guo says the wheat grew much better in the pots with biochar. The soil was amended⁷ with two percent charcoal. But he says even a one percent treatment would increase productivity.

The results demonstrated that biochar can increase organic matter in soil. Loss of nutrients⁸ in soil is an increasing problem worldwide as farmers try to grow more food for expanding populations.

Soils with less than three percent organic matter are generally poor and dense and unable to hold enough water and nutrients. Adding compost and animal manure⁹ and leaving crop wastes in fields has only a limited effect. The scientists say these added organic materials quickly break down into carbon dioxide.

Next the team will carry out a five-year study of biochar with spinach¹⁰, green peppers and tomatoes.

Mingxin Guo says he learned about the "black gold" in Brazil from a magazine story. He explains that it was discovered in the jungle, in the area where waters flow to the Amazon, in the nineteen sixties. But it was not until recent years that scientists began to bring public attention to it.

And that’s the VOA Special English Agriculture Report, written by Jerilyn Watson. For more of our reports, go to voaspecialenglish.com. I'm Jim Tedder¹¹.

1 charcoal   

n.炭，木炭，生物炭

参考例句：

• We need to get some more charcoal for the barbecue.我们烧烤需要更多的碳。
• Charcoal is used to filter water.木炭是用来过滤水的。

2 transcript   

n.抄本，誊本，副本，肄业证书

参考例句：

• A transcript of the tapes was presented as evidence in court.一份录音带的文字本作为证据被呈交法庭。
• They wouldn't let me have a transcript of the interview.他们拒绝给我一份采访的文字整理稿。

3 dense   

a.密集的，稠密的，浓密的；密度大的

参考例句：

• The general ambushed his troops in the dense woods. 将军把部队埋伏在浓密的树林里。
• The path was completely covered by the dense foliage. 小路被树叶厚厚地盖了一层。

4 tribal   

adj.部族的，种族的

参考例句：

• He became skilled in several tribal lingoes.他精通几种部族的语言。
• The country was torn apart by fierce tribal hostilities.那个国家被部落间的激烈冲突弄得四分五裂。

5 demonstration   

n.表明，示范，论证，示威

参考例句：

• His new book is a demonstration of his patriotism.他写的新书是他的爱国精神的证明。
• He gave a demonstration of the new technique then and there.他当场表演了这种新的操作方法。

6 poultry   

n.家禽，禽肉

参考例句：

• There is not much poultry in the shops. 商店里禽肉不太多。
• What do you feed the poultry on? 你们用什么饲料喂养家禽?

7 Amended   

adj. 修正的 动词amend的过去式和过去分词

参考例句：

• He asked to see the amended version. 他要求看修订本。
• He amended his speech by making some additions and deletions. 他对讲稿作了些增删修改。

8 nutrients   

n.（食品或化学品）营养物，营养品( nutrient的名词复数 )

参考例句：

• a lack of essential nutrients 基本营养的缺乏
• Nutrients are absorbed into the bloodstream. 营养素被吸收进血液。 来自《简明英汉词典》

9 manure   

n.粪，肥，肥粒；vt.施肥

参考例句：

• The farmers were distributing manure over the field.农民们正在田间施肥。
• The farmers used manure to keep up the fertility of their land.农夫们用粪保持其土质的肥沃。

10 spinach   

n.菠菜

参考例句：

• Eating spinach is supposed to make you strong.据说吃菠菜能使人强壮。
• You should eat such vegetables as carrot,celery and spinach.你应该吃胡萝卜、芹菜和菠菜这类的蔬菜。

11 tedder   

n.（干草）翻晒者，翻晒机

参考例句：

• Jim Tedder has more. 吉姆？特德将给我们做更多的介绍。 来自互联网
• Jim Tedder tells us more. 吉姆？泰德给我们带来更详细的报道。 来自互联网