Crops are getting more diverse globally. But not on our plates

Despite rising crop diversity globally, our plates are increasingly dominated by only a few of them, according to a new paper in PLOS ONE. And leaving profits aside, the trend leaves no winners in the long term.

To explore the trend, a team of researchers from the University of Toronto analyzed data on over 160 plant groups for the period from 1961 to 2014. Their findings suggest that despite a general diversification of crops grown, a number of factors have been steadily pushing less popular crops to the fringes. Thus, we can now see wheat, maize, soy and rice covering around half of all the agricultural areas globally.

Among the major causes are widespread government subsidies to crops like soy and wheat that helped to kick off their initial expansion globally. Other factors are more specific to different regions and may include trade agreements, market forces, population growth and environmental change.

The outcome: farms are growing more and more similar, killing off the evolutionary diversity and uniqueness of local agriculture around the world. And according to Adam Martin, a lead author of the paper, the planet as a whole is going to bear the outcomes if we don’t change this.

A threat is that the decreasing genetic diversity of crops makes the food system much more vulnerable to pests, diseases and environmental stresses. While certain strains of a crop might be more viable from the market perspective, they are far less so from the ecosystem-based one, which acknowledges the long history of ecological relations and unique traits of locally-adapted species.

According to the researchers, such a tendency to impact ecosystems on a global scale is a landmark feature of the Anthropocene, a conceptual epoch emphasizing the power of humans to shape the path of life on Earth.

To live through this time responsibly, the team argues for more humane and ecologically aware policies at regional scales, supporting diverse local polycultures. Researchers also emphasize the need for stronger international collaboration on acknowledging the important links between agriculture, biodiversity and other sustainability issues.