- New study reveals organic farming yields fall short of conventional farming by an average of 25%
- Organic cereals and vegetables fare worst, while fruits and oilseed crops nearly match conventional yields
- Study's co-author says organic/conventional debates are often quite heated
- "We should not be looking for the silver bullet solution, but rather combining different approaches," says co-author
Organic farming is widely perceived to be a healthy, more environmentally-friendly alternative to conventional agricultural techniques.
But its role in providing for an increasingly crowded planet remains unclear with its merits hotly contested.
New research looks set to refuel the debate revealing yields from organic farming to be, on average, 25% lower than conventionally-farmed produce.
Reporting in the science journal Nature, researchers from Canada's McGill University and the U.S.'s University of Minnesota say that the differences are not uniform across every crop with some performing better than others.
The comprehensive analysis of current scientific literature compared 316 organic and conventional crops across 34 species from 62 study sites.
Organic cereals and vegetables fared worst with yields 26% and 33% respectively lower than conventional agriculture.
But other organic produce fared much better.
Legumes (e.g. soybeans) were 11% lower while fruits were almost comparable with conventional farming with yields just 3% lower.
"I think what we were able to do is identify situations where organic agriculture performs well and situations where (it) is not so good," said co-author Verena Seufert from McGill University.
"What we should do is try to address the issues and build systems that achieve high organic yields,"she added.
Researchers say higher quantities of nitrogen in the soil enable organic crops to perform better while pH-neutral soils can also provide a better growing environment.
Adhering to the best organic management practices can also help, closing the average yield gap with conventional farming to just 13%, according to researchers.
Achieving sustainable food security will require many different farming techniques including organic, conventional and possibly "hybrid" systems, researchers say, enabling food production at affordable prices for both farmers and consumers, while limiting the impact on the environment.
"We need to have a more nuanced debate about organic versus conventional agriculture. Instead of saying it's an either/or, or it's black and white, we need to take the best of both approaches and identify the situations that work and those that don't," Seufert said.
As the study points out, numerous comparative studies of organic and conventional yields have already been conducted with conflicting results.
A 2007 study "Organic agriculture and the global food supply" concluded organic food could match and, in some instances, exceed the production of conventional farming.
But, as Seufert and colleagues point out, the findings were queried for use of data from "crops not truly under organic management and inappropriate yield comparisons."
The new study has attempted to address some of the criticisms by limiting analysis to "truly" organic systems.
Food is an emotional topic, says Seufert and much more than about consuming nutrients.
"There are a lot of social and cultural values that we associate with food. So many of these food debates -- like meat or vegetarian diets, about local or global food systems -- all of these debates are often quite heated," she said.
"What we need to do is to try and understand the arguments on both sides and assess the different options as objectively as possible, by supporting them with empirical evidence.
"Maybe we should not be looking for the silver bullet solution, but rather combining different approaches and taking the best from different suggestions."
But Megan Kintzer, director of development at the Rodale Institute, an organic farm and research center in Pennsylvania, says that organic farming is a more sustainable system.
"There is less energy use from organic farming, and the conventional systems produce 40% more greenhouse gases," Kintzer said.