A new University of Toronto study suggests that globally we’re growing more of the same kinds of crops, and this presents major challenges for agricultural sustainability.
The study, done by an international team of researchers led by U of T assistant professor, Adam Martin, used data from the UN’s Food and Agricultural Organization (FAO) to look at which crops were grown where from 1961 to 2014.
They found that within regions crop diversity has actually increased — in North America for example, 93 different crops are now grown compared to 80 back in the 1960s. The problem, Martin says, is that on a global scale we’re now seeing more of the same kinds of crops being grown on much larger scales.
In other words, large industrial-sized farms in Asia, Europe, North and South America are beginning to look the same.
“What we’re seeing is large monocultures of crops that are commercially valuable being grown in greater numbers,” says Martin.
“So large industrial farms are often growing one crop species, which are usually just a single genotype.”
Soybeans, wheat, rice and corn are prime examples. These four crops alone occupy just shy of 50 per cent of the world’s entire agricultural lands.
It’s widely assumed that the biggest change in global agricultural diversity took part during the so-called Columbian exchange when the old and new worlds met.
But the authors found that in the 1980s there was a massive increase in global crop diversity as different types of crops were being grown in new places. By the 1990s that diversity flattened out, and has begun to decline.