What we grow is as important as how we grow it, and some researchers are looking to hardier food crops and biodiversity as a solution to help increase yields. Our industrial food system focuses on what's called monocropping, which means that farmers plant the same crops on the same land year after year. Monocropping means less biodiversity in the field, which over time is bad for yields. A large-scale 2009 study in China found a 33.2 to 84.7 percent increase in production when farmers grew a mix of crops in their fields, rather than focusing on just one [source: Li].
Some experts advocate a switch from annual crops to perennial. Annual crops like corn need to be re-planted year after year, but perennials come back without replanting. As Shulman points out, that makes them hardy, so they use less fertilizer and less water. These types of plants are also more resilient to environmental changes, like a super hot summer. The extreme summer drought of 2012 destroyed the corn crop, but perennial grains didn't have this problem.
The Land Institute -- a Kansas-based research entity on food -- suggests that a switch to perennial grains could also help increase yield by making crops more weather-resistant, using less water, and reducing soil erosion, thanks to their deeper roots [source: Kunzig]. Perennial hybrids, like wheat-wheatgrass, are hardier and use less water and can be made into flour, just like the annual wheat we're used to seeing in fields now.
So, why aren't we growing more perennial crops and focusing on biodiversity in our farming on a larger scale? Our food system is pretty entrenched in a monocropping system. Farmers who have been growing corn year after year for decades may not be keen on growing varieties of food or on growing something new. Some crops receive government subsidies while others don't. There also hasn't been enough research on perennials to convince farmers to make the switch [source: Kunzig].