Plus, crop yields vary hugely. Where I live now has lots of "arable" land. It used to grow cotton and/or sugar cane. But, because of the steep, rocky landscape, unless it was terraformed into terraces, it was incredibly labor intensive to grow. That works for high-value crops, but it's not going to work for standard food crops.

We have friends who are trying to launch an aquaponics initiative, to produce more standard food crops.