It's one of the biggest and oldest debates when it comes to conventional vs. organic - can organic feed the world? A new study looks at this issue and adds some points for the conventional agriculture side of the debate.
The new study, published in Nature, shows that overall, conventionally grown crops may yield more than organically grown crops. Researchers used a comprehensive meta-analysis to examine global wide organic and conventional farming systems and their respective yields. The analysis of all available data shows that organic farming practices result in lower yields, typically than conventional practices.
However, according to the researchers, the yield differences are highly contextual, depending on many variables such as system and site characteristics, plus yields ranged wildly by type of crop. For example, rain-fed legumes and perennials on weak-acidic to weak-alkaline soils had 5% lower organic yields, but in general yields from organic farming in developed countries were 20% lower than conventional results. That said, when organic farming is done under specific conditions, such as with good management practices, particular crop types and growing conditions, the organic crops nearly matched conventional yields.
Verena Seufert, an Earth system scientist at McGill University in Montreal, Canada, and the study's lead author reports to Nature, "I think organic farming does have a role to play because under some conditions it does perform pretty well, but overall, organic yields are significantly lower than conventional yields."
A limit of this analysis include low past study availability. Just 66 studies comparing the yields of 34 different crop species in organic and conventional farming systems were used. What was different here is that the researchers included only studies that assessed the total land area used, which means they were able to compare crop yields per unit area. In contrast other studies that show larger organic yields don't look at the total size of the area planted.
According to the report's summary, you may well need the best management practices and growing conditions to produce higher organic yields to be able to more fully establish organic agriculture. Additionally, the report points out that the factors that limit organic yields are not fully understood and deserve more extensive research.