News

Study: Most Organic Crops Fall Short on Yields

Lower yields means feeding world organically requires clearing more land

A new study shows organic crops typically yield less than those raised with artificial fertilizers and pesticides.
A new study shows organic crops typically yield less than those raised with artificial fertilizers and pesticides.

Some organic crops produce nearly as much as conventional agriculture, but most still fall short, according to a new analysis.  

With a growing world population and limited land available to feed it, the study has implications for the debate on how to feed the world sustainably.

But some note there is more to sustainability than just crop yields.

Organic advocates say farming without artificial fertilizers and pesticides has less environmental impact.

But skeptics note organic farming generally produces less food per hectare. Lower yields means feeding the world organically would require clearing more land. Deforestation for agriculture is already a major contributor to climate change and biodiversity loss.

The new study in Nature looks at how big the gap is between conventional and organic yields.

More productive

The study combines 66 earlier yield studies. “Conventional yields are typically higher than organic yields, but with certain management practices, certain environmental conditions, and certain crop species this yield difference can be quite small,” says lead author and McGill University researcher Verena Seufert.

On average, organic crops produced 25 percent less than conventional.

Vegetables and cereal crops (maize and wheat, for example) performed worse: 33 and 26 percent, respectively. But organic fruits and other perennials nearly matched conventional yields. So did legume crops like soybeans that produce some of their own fertilizer.

The organic penalty was smaller on organic farms that relied on rainfall, which were 17 percent less productive, compared to irrigated farms, which fell behind by 35 percent.

“Under rainfed conditions where water supply varies depending on weather conditions, the organic soil can actually provide water better to the crops because it can capture and maintain this water for longer,” Seufert says.

Harder to manage

One area where organic farmers could improve, she says, is giving their crops enough nitrogen fertilizer. Those that received more nitrogen had smaller yield differences, she says.

But that’s harder to do organically with just manure and crop rotations, she says.

“In conventional agriculture, you just dump inorganic nitrogen fertilizer on the plants and they grow; while in organic agriculture, you need to manage the system. You need to manage the soil. You need to improve the soil quality,” Seufert says.

And besides fertilizers, farms that also used industry-standard best management practices for weeds and pests reached nearly 90 percent of conventional yields.

Land issue

If organic crops were given the right amount of nutrients and protected from weeds and pests, they could produce the same amount as conventional crops, says agronomist Ken Cassman at the University of Nebraska at Lincoln.

But he says that’s not the issue.  

“The problem is the land issue, if you’re talking global food security,” he says. “Because either you’ve got to have [a] longer [crop] rotation or you have to bring nutrients from outside the system somehow.”

Organic farmers rotate food crops with plants that fertilize the soil. But while fertilizer crops are growing, food crops are not. So food has to be grown somewhere else.

Or farmers fertilizer with manure. But it takes grazing land or crop land to feed the animals that make the manure.

The world’s food demand will grow by 70 percent by mid-century, according to the United Nations. Cassman says researchers need to figure out how to meet the demand on the same amount of land that farmers are using today.

“There really isn’t much good land left that’s not, for instance, rainforest, or wetlands, or grassland savannah, which are the last carbon-rich and biodiverse regions that we have,” he says.

Hybrid farming

“I think when people see these studies, their first reaction is, ‘Well, my goodness, organic farming can’t feed the world,’” says Washington State University soil scientist John Reganold. “Guess what? Conventional farming cannot sustainably feed the world.”

He says it takes a lot of energy to make artificial fertilizer, and experts say some key ingredients are running out.

And he adds that sustainability means more than just producing high yields, according to the U.S. National Academy of Sciences. The environment, social justice and economic viability are important, too.

He says organic and conventional systems are bookends - extremes at opposite ends of the spectrum. He says more and more, farming is becoming a hybrid of both.

The University of Nebraska's Ken Cassman says the arguments over ideology are a distraction.

“You don’t focus on whether organic is better or conventional is better,” he says. “You simply focus on the outcome.”

“In my personal food decisions, I have a mix," says study author Verena Seufert. "And I think we do have to have to have that on a larger scale.”

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Getting it Done Beyond a Nuclear Deali
X
July 07, 2015 12:02 PM
If a nuclear deal is reached between Iran and world powers in Vienna, it will be a highly technical road map to be used to monitor nuclear activity in Iran for years to come to ensure Tehran does not make nuclear weapons. Equally as complicated will be dismantling international sanctions that were originally intended to be ironclad. VOA’s Heather Murdock talks to experts about the key challenges any deal will present.
Video

Video Getting it Done Beyond a Nuclear Deal

If a nuclear deal is reached between Iran and world powers in Vienna, it will be a highly technical road map to be used to monitor nuclear activity in Iran for years to come to ensure Tehran does not make nuclear weapons. Equally as complicated will be dismantling international sanctions that were originally intended to be ironclad. VOA’s Heather Murdock talks to experts about the key challenges any deal will present.
Video

Video Rice Farmers Frustrated As Drought Grips Thailand

A severe drought in Thailand is limiting the growing season of the country’s important rice crop. Farmers are blaming the government for not doing more to protect a key export. Steve Sandford reports from Chiang Mai, Thailand.
Video

Video Making Music, Fleeing Bombs: New Film on Sudan’s Internal Refugees

In 2012, Sudanese filmmaker Hajooj Kuka went to make a documentary among civil war refugees in Sudan’s Blue Nile and Nuba Mountains region. What he found surprised him: music was helping to save people from bombing raids by their own government. VOA’s Carolyn Weaver has more.
Video

Video 'From This Day Forward' Reveals Difficult Journey of Transgender Parent

In her documentary, "From This Day Forward", filmmaker Sharon Shattuck reveals the personal journey of her transgender father, as he told his family that he always felt he was a woman inside and decided to live as one. VOA’s Penelope Poulou has more.
Video

Video Floodwaters Threaten Iconic American Home

The Farnsworth House in the Midwest State of Illinois is one of the most iconic homes in America. Thousands of tourists visit the site every year. Its location near a river inspired the design of the house, but, as VOA’s Kane Farabaugh reports, that very location is now threatening the existence of this National Historic Landmark.
Video

Video Olympics Construction Scars Sacred Korean Mountain

Environmentalists in South Korea are protesting a Winter Olympics construction project to build a ski slope through a 500-year-old protected forest. Brian Padden reports that although there is strong national support for hosting the 2018 Pyeongchang Winter Olympics, there are growing public concerns over the costs and possible ecological damage at the revered mountain.
Video

Video Xenophobia Victims in South Africa Flee Violence, Then Return

Many Malawians fled South Africa early this year after xenophobic attacks on African immigrants. But many quickly found life was no better at home and have returned to South Africa – often illegally and without jobs, and facing the tough task of having to start over. Lameck Masina and Anita Powell file from Johannesburg.
Video

Video Family of American Marine Calls for Release From Iranian Prison

As the crowd of journalists covering the Iran talks swells, so too do the opportunities for media coverage.  Hoping to catch the attention of high-level diplomats, the family of American-Iranian marine Amir Hekmati is in Vienna, pleading for his release from an Iranian prison after nearly 4 years.  VOA’s Heather Murdock reports from Vienna.
Video

Video UK Holds Terror Drill as MPs Mull Tunisia Response

After pledging a tough response to last Friday’s terror attack in Tunisia, which came just days before the 10th anniversary of the bomb attacks on London’s transport network, British security services are shifting their focus to overseas counter-terror operations. VOA's Henry Ridgwell has more.
Video

Video Obama on Cuba: This is What Change Looks Like

President Barack Obama says the United States will soon reopen its embassy in Cuba for the first time since 1961, ending a half-century of isolation. VOA White House correspondent Luis Ramirez reports.
Video

Video Hate Groups Spread Influence Via Internet

Hate groups of various kinds are using the Internet for propaganda and recruitment, and a Jewish human rights organization that monitors these groups, the Simon Wiesenthal Center, says their influence is growing. The messages are different, but the calls to hatred or violence are similar. VOA's Mike O’Sullivan reports.
Video

Video Blind Somali Journalist Defies Odds in Mogadishu

Despite improving security in the last few years, Somalia remains one of the most dangerous countries to be a journalist – even more so for someone who cannot see. Abdulaziz Billow has the story of journalist Abdifatah Hassan Kalgacal, who has been reporting from the Somali capital for the last decade despite being blind.

VOA Blogs