Debates about feeding the world often come back to a simple claim that also underpins supply-demand projections: “They’re not making any more farm land.”

“The U.S., Canada, Australia, the European Union, Argentina, even Russia and China are fairly tapped out when it comes to arable land,” says Jay O’Neil, senior agricultural economist at Kansas State’s International Grains Program.

That’s borne out by the 2014 USDA Long-term Projections, which show those producer nations expanding harvested corn areas by less than 14 million acres over the next decade.

“The only major producer today with enough potential land mass for a major expansion is Brazil,” he continues, suggesting that most new production will come from yield increases.

However, some analysts argue that currently untapped potential acres could change this supply-demand equation.

untapped arable acres

In the former Soviet Union, 74 million acres that were farmed in the late 1970s sat idle in 2012, roughly equivalent to total U.S. soybean acres, Ray Wyse, senior director of trading for Gavilon, told a Federal Reserve agricultural summit last year.

Brazil has 470 million in untapped potential acres, and the Democratic Republic of Congo, with a climate and water resources similar to Brazil’s, offers an additional 200 million acres and can produce three crops a year.