The Next Big Thing in Agriculture May Be Very Small

From VOA Learning English, this is Science in the News.

I'm Anna Matteo.

And I'm Christopher Cruise.

Today we tell how some extremely small organisms may help meet our food needs in the future. Then, we report on an American project to save endangered orchids. Finally, we tell about the discovery of what British scientists are calling the oldest human footprints found outside of Africa.

Small Organisms May Help Meet Food Needs of the Future

Experts say farmers will need to produce about 70 percent more food by the middle of the century. They predict that nine billion people will need to be fed worldwide by 2050.

The prediction means experts will need to develop more-effective farming methods that cause less harm to the environment. Experts say living things called "microbes" could help meet that need. A microbe is an organism so small it can be seen only with a microscope.

Jeff Dangl is a biology professor at the University of North Carolina. He says researchers are finding extremely small organisms in the ground.

"This soil was teeming with life."

Jeff Dangl says one gram of soil contains between 100 million and one billion microbes.

He says microbes are taking part in a healthy exchange with the plants that share the soil. Around plant roots, microbes change chemicals in the air and soil into food for the plants. The microbes include bacteria and material known as "fungi."

Some microbes act as bodyguards. They produce anti-bodies and other chemicals to fight harmful germs.

Plants make sugar through a process called "photosynthesis." This happens when a plant receiving light changes water and carbon dioxide into food.

Professor Dangl says much of the sugar is pumped down through the roots. There, it is turned into sugar-based microbe food and released into the soil. He says that is done to get microbes to help the plants grow better. Some of the organisms turn chemicals in the air and soil into food that the plants can eat.

The microbes produce antibiotics and other chemicals to fight the harmful germs. Professor Dangl said bacterial and fungal parts of the plant organism must be considered to understand how plant organisms operate.

The biosciences company Novozymes already sells one kind of fungi that helps plants get phosphorous from the soil.

Shawn Semones is the head of product research for the company. At an experimental greenhouse in Virginia, he is treating the roots of corn plants with a microscopic fungus.

He holds a small plastic cup which has a dead insect inside. The insect is developing a fine white coat of mold -- a substance that grows on living organisms. That mold killed the insect. The white covering is producing spores that will blow in the wind to infect another insect.

Shawn Semones says the microbe develops naturally. He says Novozymes has found a way to produce it in very large amounts and offer it to farmers as a bio-pesticide. A bio-pesticide protects crops from animals, microbes, bacteria and fungi.

Novozymes recently signed a $300 million deal with Monsanto, a company best known for producing seeds and chemicals. The goal is to help bring discoveries about microbes to farmers' fields.

You are listening to the VOA Learning English program Science in the News. With Christopher Cruise, I'm Anna Matteo in Washington.

Project to Save Endangered Orchids Growing in Florida

Our planet is home to 20,000 kinds of orchids. Orchids exist on almost every continent. But the beautiful and valuable flowers live mainly in warm, moist climates like that found in the southern part of Florida.

America's "sunshine state" has about 50 native species of orchid. But many are in danger of dying out. This threat has led scientists to launch a five-year project to save them.

Carl Lewis directs Miami's Fairchild Tropical Botanical Garden. He says many orchid species native to Florida have become rare.

"Most of those orchids are very difficult to find now. They've, they've been hunted almost to extinction in the wild. So, really, we launched this project just as an effort to bring those orchids back."

The project to grow and plant one million orchid seedlings began two years ago. Orchids grow mostly on trees. But their seedlings are extremely small, delicate and weak. So they start their life in a laboratory.

The seeds grow in clean bottles with required nutrients. After that, the young plants are moved to a warming device with LED lights. Next, they go to a nursery -- an area where plants are grown. Two years may pass before the plants are strong enough to be connected to -- or fixed onto -- trees.

Volunteers help Carl Lewis to transplant -- or move -- the orchid plants. He says it is important to transplant enough older orchids so they can continue to reproduce without that help.

"This is supposed to be an infusion, just to get so many out there that they start to reproduce on their own."

After these plants are moved to areas where other orchids grow, scientists hope insects and tiny organisms will find the orchids.

The campaign to save native orchids also depends on help from local students. They have been asked to watch the transplanted orchids in their neighborhoods. A number of plants will also be given away to try to reduce the chance that people will steal them off the trees.

The Center for Plant Conservation guides the conservation and study of threatened plants across the United States. The center is based in the city of St. Louis, Missouri.

Britain's Oldest Human Footprints Found on Coastline

Finally, British scientists have found what they believe are the oldest human footprints ever discovered outside of Africa. The footprints of what appears to be ancient humans were found in the seaside community of Norfolk, in eastern Britain. The scientists estimate the markings are between 800,000 and almost one million years old. They may be about 500,000 years older than the earliest footprints ever found in the country. If so, that could provide the oldest evidence of human beings in northern Europe.

Images and a model of one of the footprints were recently shown to reporters at the British Museum in London. A team of scientists found the footprints in May, 2013. The scientists work for the British Museum, Britain's Natural History Museum, and Queen Mary University of London. The researchers say ocean water from incoming tidal waves made it impossible to remove the prints from the coast.

The area appears to have 50 footprints of both adults and children. They were found near the village of Happisburg. The British Museum says the Happisburg area has what it calls a "remarkable concentration" of early Stone Age archeological sites. All were found since 2000.

Archeologist Nick Ashton described how he felt when he recognized the footprints came from prehistoric humans. At the time, he was looking at e-mails on his computer.

"It was only when the, this overhead views e-mailed through to me back in my office I suddenly looked at it and opened up the file and I thought, ‘This is absolutely amazing, you know -- there, there is no doubt this is really is human footprints."

He says the discovery will change the understanding of early human history in Europe.

The researchers estimate the height of the early humans at between about .93 and 1.73 meters. The difference in the heights suggests a group of mixed ages.

Isabelle de Groote is with Liverpool John Moores University in the city of Liverpool. She examined the footprints. She says the markings help to tell about the humans who may have made them.

"The spread of the footprint size gives us an indication that we have children, a number of children and then probably some adults there with at least one, you know with probably one, male."

One footprint appears to show the mark of toes.

Scientists say Britain was joined to continental Europe about a million years ago. It is not known how the early humans survived in the cold climate of northern Europe. Scientists believe the creatures who left the footprints were related to Pioneer Man, an ancestor of Homo sapiens. Pioneer Man was known to have lived in a warmer climate.

Researchers continue looking for human fossil remains in the Happisburg area. A report on the footprint discovery and its meaning was published in the journal PLOS ONE.

This Science in the News was written by Jerilyn Watson. It was based on stories from VOA reporters Steve Baragona and George Putic. Christopher Cruise produced the program.

I'm Anna Matteo.

And I'm Christopher Cruise.

To comment on this program, go to our website, tingvoa.com. While you are there, you can read, listen to and download our programs. You can follow us on Facebook, iTunes, LinkedIn, Twitter and on our YouTube Channel, all at VOA Learning English.

Join us again next week for more news about science on the Voice of America!

词汇解析

finding

难度：5星基本词汇，属常用1000词

英汉解释

n.调查(或研究)的结果;[律] 裁决

find的现在分词.

参考例句

用作名词 (n.)

The finding is based on such an inquiry.

基于如上调查所得出的发现

bacteria

英汉解释

n.(复数)细菌

参考例句

用作名词 (n.)

Many diseases are caused by bacteria.

许多疾病是由细菌引起的。

carbon

难度：4星核心词汇，属常用3000词

英汉解释

n.碳;复写纸;复本;碳精棒

参考例句

用作名词 (n.)

Carbon dioxide consists of carbon and oxygen.

二氧化碳是由碳和氧组成的。

moist

难度：3星常用词汇，属常用6000词

英汉解释

adj.潮湿的;湿润的;[医]湿性的

参考例句

用作形容词 (adj.)

This gave a warm and moist feeling to the picture.

这样让整张画有了些温暖和潮湿的感觉。

launch

难度：4星核心词汇，属常用3000词

英汉解释

v.发起;推出(新产品);发射;使(船)下水

n.发射;产品推介

参考例句

用作动词 (v.)

The company researched the market demand and decided to launch their new product.

这家公司调查了市场需求，决定推出新产品。

The people all over the country exulted in the success in launching a new satellite.

全国人民为成功地发射了一颗新的人造卫星而欢欣鼓舞。

用作名词 (n.)

We have got good media coverage for the launch of the new model.

传播媒介对我们的新型产品投放市场作了有利的报导。

transplant

难度：3星常用词汇，属常用6000词

英汉解释

v.移居;移栽(植物);移植(器官)

n.移植;移植物

参考例句

用作动词 (v.)

It is now possible to transplant organs from animals into people.

现在将动物身上的器官移植入人体内已经成为了可能。

用作名词 (n.)

The transplant was rejected by the body.

移植器官遭到了身体的排斥。

conservation

难度：3星常用词汇，属常用6000词

英汉解释

n.保存;保护;守恒;节约

参考例句

用作名词 (n.)

If I may refer back to the problem we discussed, I think we shall stress on the conservation of our natural resource.

请允许我重提我们刚才讨论过的问题，我想我们应该强调保存我们的自然资源。

Who discovered the conservation of energy?

谁发现了能量守恒?

overhead

难度：3星常用词汇，属常用6000词

英汉解释

n.经常开支;普通用费

adj.高架的;在头上的

adv.在头顶上;在空中;在高处

[计算机] 总开销.

参考例句

用作名词 (n.)

Their office is in central Beijing, so their overhead is very high.

他们的办事处设在北京市中心，所以他们的日常开支很大。

用作形容词 (adj.)

This button turns on your overhead light.

这个按钮用来开亮您头顶上方的灯。

用作副词 (adv.)

The lantern hanging overhead swung in the wind.

吊在高处的灯在风中摇动。