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.
Turkey's Main Opposition Party Hopes for Election Breakthroughi
X
May 22, 2015 10:23 AM
Turkey’s main opposition Republican People’s Party has sought an image change ahead of the June 7 general election. The move comes after suffering successive defeats at the hands of the Islamist-rooted AK Party, which has portrayed it as hostile to religion. Dorian Jones reports from the western city of Izmir.
Video

Video Turkey's Main Opposition Party Hopes for Election Breakthrough

Turkey’s main opposition Republican People’s Party has sought an image change ahead of the June 7 general election. The move comes after suffering successive defeats at the hands of the Islamist-rooted AK Party, which has portrayed it as hostile to religion. Dorian Jones reports from the western city of Izmir.
Video

Video Europe Follows US Lead in Tackling ‘Conflict Minerals’

Metals mined from conflict zones in places like the Democratic Republic of Congo are often sold by warlords to buy weapons. This week European lawmakers voted to force manufacturers to prove that their supply chains are not inadvertently fueling conflicts and human rights abuses. Henry Ridgwell reports from London.
Video

Video Class Tackles Questions of Race, Discrimination

Unrest in some U.S. cities is more than just a trending news item at Ladue Middle School in St. Louis, Missouri. As VOA’s Kane Farabaugh reports, it’s a focus of a multicultural studies class engaging students in wide-ranging discussions about racial tensions and police aggression.
Video

Video Mind-Controlled Prosthetics Are Getting Closer

Scientists and engineers are making substantial advances towards the ultimate goal in prosthetics – creation of limbs that can be controlled by the wearer’s mind. Thanks to sophisticated sensors capable of picking up the brain’s signals, an amputee in Iceland is literally bringing us one step closer to that goal. VOA’s George Putic reports.
Video

Video Afghan Economy Sinks As Foreign Troops Depart

As international troops prepare to leave Afghanistan, and many foreign aid groups follow, Afghans are grappling with how the exodus will affect the country's fragile economy. Ayesha Tanzeem reports from the Afghan capital, Kabul.
Video

Video Poverty, Ignorance Force Underage Girls Into Marriage

The recent marriage of a 17-year old Chechen girl to a local police chief who was 30 years older and already had a wife caused an outcry in Russia and beyond. The bride was reportedly forced to marry and her parents were intimidated into giving their consent. The union spotlighted yet again the plight of many underage girls in developing countries. Zlatica Hoke reports poverty, ignorance and fear are behind the practice, especially in Asia and Africa.
Video

Video South Korea Marks Gwangju Uprising Anniversary

South Korea this week marked the 35th anniversary of a protest that turned deadly. The Gwangju Uprising is credited with starting the country’s democratic revolution after it was violently quelled by South Korea’s former military rulers. But as Jason Strother reports, some observers worry that democracy has recently been eroded.
Video

Video California’s Water System Not Created To Handle Current Drought

The drought in California is moving into its fourth year. While the state's governor is mandating a reduction in urban water use, most of the water used in California is for agriculture. But both city dwellers and farmers are feeling the impact of the drought. Some experts say the state’s water system was not created to handle long periods of drought. Elizabeth Lee reports from Ventura County, an agricultural region just northwest of Los Angeles.
Video

Video How to Clone a Mammoth: The Science of De-Extinction

An international team of scientists has sequenced the complete genome of the woolly mammoth. Led by the Swedish Museum of Natural History in Stockholm, the work opens the door to recreate the huge herbivore, which last roamed the Earth 4,000 years ago. VOA’s Rosanne Skirble considers the science of de-extinction and its place on the planet
Video

Video Blind Boy Defines His Life with Music

Cole Moran was born blind. He also has cognitive delays and other birth defects. He has to learn everything by ear. Nevertheless, the 12-year-old has had an insatiable love for music since he was born. VOA’s June Soh introduces us to the young phenomenal harmonica player.

VOA Blogs