On an important note, to avoid too much work (I understand, I've run many RPs in different formats, as previously demonstrated I'm knew to the forum type), you might want to borrow from existing IPs, partially anyways. Fallout seems like an attractive option, particularly. I've done similar things before. Radstags and brahmin and the such. Mutfruit, corn (something like the variety I wrote about), tatos, etc.

*My advice is my own opinion, of course, take it or leave it. But I would appreciate some idea in just how developed agriculture is. From the way it sounds, I imagine somewhere around the fallout games? Maybe a bit behind?