Yes that's what people doing in Asia and Europe where they have less land but it's useful mostly for vegetables, not for tradational crops.. I know ppl who are using similar method geting 3 produces, one above the ground, one under the ground and one going up vertically. 3 in 1,called multi farming, but here you guys have vast lands... so not sure farmers will adopt it here or no. But back to your point, it's great way to earn more from little space, here in New York city people are renting vacant building and doing vertical farming to meet NYC need of vegetables.