The Bronx is getting fresh with Brooklyn.

The world’s largest rooftop farm may soon take root in Hunts Point — a proposed 200,000-square-foot project that’s double the size of the much-touted, massive hydroponic greenhouse already being built atop a building in Sunset Park, Brooklyn.

The Bronx project would be able to produce about 3 1/2 football fields’ worth of fresh crops a year when it’s completed.