How science could spark a second Green Revolution

To fight poverty and overpopulation, crops need coaxing. Advances in deep-root food plants may trigger a new Green Revolution.

By , Staff writer

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    A Malawian child sits among harvested corn near Linongwe, the capital. A team of US researchers is working to promote a second Green Revolution, focusing on resilient crops and simple, effective practices for marginal lands.
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    Chinese farmers prepare for planting in Yongjing. China’s shift from being a food importer to being more self-sufficient could be instructive for some in Africa hoping for a new Green Revolution.
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Jonathan Lynch wants to get at the roots of the problem of producing enough food for humanity. Literally.

In projects around the world, the professor of plant nutrition at Pennsylvania State University and his colleagues are trying to develop crops whose root systems can resist drought and take up fertilizer from the soil more efficiently.

With world population expected to grow by nearly 50 percent to more than 9 billion people by midcentury, farmland is going to need to be much more productive. Even today, nearly 1 out of every 6 people in the world – more than 1 billion – are going hungry, according to the United Nations Food and Agriculture Organization.

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With most good farmland already under cultivation, any new acreage would likely be in marginal land with either poor soil conditions or little rainfall. What's more, climate change is expected to make some regions drier or hotter, which may send crop yields plummeting.

What the world needs, say Dr. Lynch and others, is a new Green Revolution that can increase yields in the face of challenging and changing conditions.

"The idea that we could fertilize and irrigate our way out of this problem was the first Green Revolution" led by Nobel Peace Prize-winner Norman Borlaug and others, Lynch says. The second Green Revolution is going to be how we get plants to grow productively with less water and artificial fertilizer, he says.

That's where Lynch's idea for improving roots comes in. He calls the concept "steep, cheap, and deep" – developing crop roots that grow steeper and deeper into the soil, making them able to find more moisture and nutrients, thereby reducing need for irrigation and nitrogen fertilizers. (With crops that rely on phosphorus, he's breeding shallow roots, since phosphorus is typically found in topsoil.)

Working with bean breeders around the world, for example, Lynch's team has identified root traits that can produce "two or three times more food without fertilizer," he says, using conventional breeding techniques that select for superior root traits.

His work on new varieties of corn is less advanced. But Lynch has published a paper that identified a previously unrecognized trait that improved yields eight times in experimental corn lines grown under drought conditions.

A key component in raising American corn yields in recent decades, nitrogen fertilizer, is more expensive in Africa than in the United States, Lynch says. In addition, as it runs off fields it can contaminate water supplies and produce nitrous oxide, a potent greenhouse gas.

While Lynch employs traditional cross-breeding methods, genetically modified (GM) crops seem likely to play an important role in the second Green Revolution. Concerns about safety and unexpected consequences have led to a slow rate of adoption in Europe and parts of Africa, although GM crops are already widely planted and consumed in the US.

"There's incredible debate over to what extent you can achieve these productivity goals without [GM crops]," says Mark Rosegrant, an economist at the International Food Policy Research Institute in Washington.

GM crops will be an "essential" part of increasing yields in Africa, says Calestous Juma, a professor of international development at Harvard University and the director of the Agricultural Innovation in Africa Project funded by the Bill & Melinda Gates Foundation. "In the medium to long run, genetic engineering is going to become inevitable," he says.

An important test case may come in the form of a new GM crop, a drought-tolerant corn variety being developed by the Monsanto Company for use in the US. But while Mr. Rosegrant sees GM crops as an "important" part of the solution, he adds, "there has to be a lot of mainstream crop breeding as well, not just one or the other."

GM or not, new crop varieties are just one part of the equation in Africa, Dr. Juma says. Also important are factors like developing road networks so that farmers have a faster way to bring crops to market. Farmers equipped with cellphones can check on market prices, receive weather forecasts, or even learn about new seeds or farming techniques.

For models of self-sufficiency, Juma points to Malawi and China. Malawi, a small landlocked country in Africa and one of the continent's poorest nations, has helped its farmers become more productive by building roads and introducing new farming techniques. The president, Bingu wa Mutharika, appointed himself minister of agriculture in order to ensure that food production would be a top government priority and that government ministries would work in concert, Juma says.

"There's absolutely no reason why other African countries can't do it" too, he says. In January, Mr. Mutharika was appointed chairman of the African Union, representing 53 countries. His slogan: "Feeding Africa through new technologies."

China's dramatic turnaround from being a food importer to having the ability to essentially feed itself is also "going to continue to be very instructive for African countries," Juma says.

The key to China's dramatic improvement has been investment in research and training, says Mark Alley, a professor of agriculture at Virginia Tech University in Blacksburg and past president of the American Society of Agronomy. But in their all-out drive to increase production, the Chinese have also "created some problems," he says. "They've pumped some aquifers dry in the north China plain, for example."

As the world steps up production, "We have to protect the water and air quality. And we have to produce safe and nutritious food," Dr. Alley says. Keeping a large portion of the Earth's surface under cultivation is not an option. "The alternative is that we starve. And that's not an alternative," he says. So better yields and sustainable practices must go hand in hand.

Alley remains optimistic that new technologies and techniques will meet the situation. In the US in the early 1900s, he points out, an acre of corn yielded about 25 bushels. Last year, an acre of corn produced an average of 162 bushels.

But sending surplus US grain to places like Africa, while an immediate help, does nothing to make Africans more self-sufficient. As the Chinese proverb puts it, "Give a man a fish and you feed him for a day. Teach a man to fish and you feed him for a lifetime."

The nice thing about improving seeds: They can be sent to a place like Africa and "nothing else has to happen," Lynch says. Farmers don't need specialized training in how to use them or need to apply more water or fertilizer to get better results.

"In Mozambique, where we work, 70 percent of the population are subsistence farmers" earning less than $1 a day, Lynch says. "They live in mud huts. They don't have shoes. They don't know how to read and write. They rarely see outsiders or get help from their own government. Many don't even live near a road. They live on what they plant in the ground and eat.

"So if we can improve their yield 10 or 20 percent with better seed," he says, "maybe they can feed their kids more, maybe they can even sell some of their crop and begin to climb out of this poverty trap."

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