While organic farming may limit the amounts of chemical fertilizers, herbicides, and pesticides entering the environment, it may not be the most efficient way to feed the world's more than 1 billion chronically hungry inhabitants, according to a new study comparing conventional and organic agricultural practices.
The study, which was published online in Nature yesterday (April 25), reanalyzed data from 66 studies comparing the yields of 34 different crops in both organic and conventional farming systems. The authors found that yields from organic farms were up to 34 percent lower than yields from conventional farms cultivating the same crop. Organic farming practices resulted in particularly low yields for wheat and some vegetables. Fruits, like strawberries, and oilseed crops, such as soybean, on the other hand, showed only modest yield reductions on organic farms; just 3 and 11 percent lower than conventional farming yields, respectively.
"I think organic farming does have a role to play because under some conditions it does perform pretty well," lead author and McGill University Earth system scientist Verena Seufert told Nature. But "overall, organic yields are significantly lower than conventional yields." Seufert and her coauthors suggested that soil nitrogen was likely one of the limiting factors in organic farming systems.