New meta-analysis shows organic can play important role in feeding the world
Here's some seasonal good news: A new meta-analysis shows that organic yields don't lag much behind conventional. On average, organic yields were 19% lower, less of a gap than older studies have found.
An earlier study, conducted over 21 years at the Rodale Institute, found even more promising results for organic. Corn and soy yields were about equal between conventional and organic farming systems, but in drought years the organic systems had significantly higher corn yields (31% higher) than the conventional system. There's more about the Rodale study here and here.
According to a press article, the new analysis "tackles the lingering perception that organic farming, while offering an environmentally sustainable alternative to chemically intensive agriculture, cannot produce enough food to satisfy the world's appetite."
1. Can organic crops compete with industrial agriculture?
2. Diversification practices reduce organic to conventional yield gap
3. Organic nearly as productive as industrial farming, new study says
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1. Can organic crops compete with industrial agriculture?
Phys.org, 9 Dec 2014
http://phys.org/news/2014-12-crops-industrial-agriculture.html
A systematic overview of more than 100 studies comparing organic and conventional farming finds that the crop yields of organic agriculture are higher than previously thought. The study, conducted by researchers at the University of California, Berkeley, also found that certain practices could further shrink the productivity gap between organic crops and conventional farming.
The study, to be published online Wednesday, Dec. 10, in the Proceedings of the Royal Society B, tackles the lingering perception that organic farming, while offering an environmentally sustainable alternative to chemically intensive agriculture, cannot produce enough food to satisfy the world's appetite.
"In terms of comparing productivity among the two techniques, this paper sets the record straight on the comparison between organic and conventional agriculture," said the study's senior author, Claire Kremen, professor of environmental science, policy and management and co-director of the Berkeley Food Institute. "With global food needs predicted to greatly increase in the next 50 years, it's critical to look more closely at organic farming because, aside from the environmental impacts of industrial agriculture, the ability of synthetic fertilizers to increase crop yields has been declining."
The researchers conducted a meta-analysis of 115 studies - a dataset three times greater than previously published work - comparing organic and conventional agriculture. They found that organic yields are about 19.2 percent lower than conventional ones, a smaller difference than in previous estimates.
The researchers pointed out that the available studies comparing farming methods were often biased in favor of conventional agriculture, so this estimate of the yield gap is likely overestimated. They also found that taking into account methods that optimize the productivity of organic agriculture could minimize the yield gap. They specifically highlighted two agricultural practices - multi-cropping (growing several crops together on the same field) and crop rotation - that would substantially reduce the organic-to-conventional yield gap to 9 percent and 8 percent, respectively.
The yields also depended upon the type of crop grown, the researchers found. There were no significant differences in organic and conventional yields for leguminous crops, such as beans, peas and lentils.
"Our study suggests that through appropriate investment in agroecological research to improve organic management and in breeding cultivars for organic farming systems, the yield gap could be reduced or even eliminated for some crops or regions," said the study's lead author, Lauren Ponisio, a graduate student in environmental science, policy and management. "This is especially true if we mimic nature by creating ecologically diverse farms that harness important ecological interactions like the nitrogen-fixing benefits of intercropping or cover-cropping with legumes."
The researchers suggest that organic farming can be a very competitive alternative to industrial agriculture when it comes to food production.
"It's important to remember that our current agricultural system produces far more food than is needed to provide for everyone on the planet," said Kremen. "Eradicating world hunger requires increasing the access to food, not simply the production. Also, increasing the proportion of agriculture that uses sustainable, organic methods of farming is not a choice, it's a necessity. We simply can't continue to produce food far into the future without taking care of our soils, water and biodiversity."
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2. Diversification practices reduce organic to conventional yield gap
Lauren C. Ponisio, Leithen K. M'Gonigle, Kevi C. Mace, Jenny Palomino, Perry de Valpine, Claire Kremen
Proceedings of the Royal Society of London B: Biological Sciences
DOI: 10.1098/rspb.2014.1396 Published 10 December 2014
http://rspb.royalsocietypublishing.org/content/282/1799/20141396
Abstract
Agriculture today places great strains on biodiversity, soils, water and the atmosphere, and these strains will be exacerbated if current trends in population growth, meat and energy consumption, and food waste continue. Thus, farming systems that are both highly productive and minimize environmental harms are critically needed. How organic agriculture may contribute to world food production has been subject to vigorous debate over the past decade. Here, we revisit this topic comparing organic and conventional yields with a new meta-dataset three times larger than previously used (115 studies containing more than 1000 observations) and a new hierarchical analytical framework that can better account for the heterogeneity and structure in the data. We find organic yields are only 19.2% (±3.7%) lower than conventional yields, a smaller yield gap than previous estimates. More importantly, we find entirely different effects of crop types and management practices on the yield gap compared with previous studies. For example, we found no significant differences in yields for leguminous versus non-leguminous crops, perennials versus annuals or developed versus developing countries. Instead, we found the novel result that two agricultural diversification practices, multi-cropping and crop rotations, substantially reduce the yield gap (to 9 ± 4% and 8 ± 5%, respectively) when the methods were applied in only organic systems. These promising results, based on robust analysis of a larger meta-dataset, suggest that appropriate investment in agroecological research to improve organic management systems could greatly reduce or eliminate the yield gap for some crops or regions.
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3. Organic nearly as productive as industrial farming, new study says
Doug Gurian-Sherman
Civil Eats, 10 Dec 2014
http://civileats.com/2014/12/10/organic-nearly-as-productive-as-industrial-farming-new-study-says/
[Excerpt only below, full article at link above]
Industrial agriculture has huge, unsustainable impacts on our environment. And while organic and other ecologically based farming systems (agroecology) have huge benefits, some have suggested that it will never produce enough food. Production is only one of the challenges for food security. But, according to new research, even by this measure, critics seem to have substantially underestimated the productivity of organic farming.
Impressive research from Iowa State University has already begun to show that agroecological systems that don’t completely eliminate synthetic chemicals can match or exceed yields from U.S. industrial grain production and provide equal or higher profits to farmers. Now, new research by a team of U.C. Berkeley scientists shows that organic systems can also be highly productive.
I want to point out that, despite the fact that we currently produce more than enough crops to feed our global population, around a billion people are hungry around the globe. And, in the meantime, we waste between 30 to 40 percent of the food we produce. In other words, crop productivity is only one piece of the food security puzzle. Food sovereignty is another important one…
[Read on at http://civileats.com/2014/12/10/organic-nearly-as-productive-as-industrial-farming-new-study-says/]