Ecological consequences

With those lower yields, feeding the world organically could require clearing more land for farms.

“We’ll have to get more land into cultivation to do it that way," says Columbia University soil scientist Pedro Sanchez, "with horrible, negative ecological consequences.”

Experts say deforestation to make way for agriculture is already contributing to climate change and a loss of biodiversity.

And farmers will have nine billion mouths to feed by mid-century, which puts agriculture in a difficult position.

“Right now, we can’t feed 9 billion people with the ways we’re farming, whether it’s conventional or organic,” says U.S. Department of Agriculture researcher Michel Cavigelli.

Working both sides

So experts are working on both sides of the equation. Cavigelli is working to improve the productivity of organic farms using natural fertilizers like chicken manure. The trouble, he says, is that often it does not provide enough nutrients.

“We need to improve all systems. And so, what’s the best way to do that, both to feed the world’s population but also to do it in the way where we’re not destroying the planet?”

Many of the African farmers Pedro Sanchez has worked with have used synthetic fertilizers to triple their yields, making a huge difference in their food security.