Whirl has a point.

Modern Ag is driven by nitrogen.

Our ability to produce nitrogen based fertilizers on an industrial scale is what has allowed us to grow unheard of amounts of crops in the 20th century.

Unfortunately, isolating and extracting nitrogen for the purpose of making acids (you’d be surprised what we use nitric acid to make), fertilizers, propellants, explosives, etc, takes a bit of doing. I seriously doubt any Joe Baggadonuts could pull it off in his garage, unless he had access to some very specialized equipment and training…

Without the ability to isolate and extract nitrogen and the ability to make nitrogen based compounds, you can forget about trying to jump-start civilization after a fall…

Vets – animal doctors? Even here in Dirtville Kentucky, we have at least 3 that I know of. My next door neighbor is a vet. And, as you’d figure, in a place like Kentucky, we don’t have any shortage of farriers or horses… though I do expect that a great many guys raising cattle will switch to whatever crops they can grow when things go sideways.

Tobacco won’t die out – too valuable, too popular. I think everyone and their brother will be breeding horses, mules and donkeys… mules are considered hard to work with, but they can go longer than horses can, can weather heat better, carry heavier loads, etc… I wouldn’t use horses or mules for plowing. Not if I had a choice. I’d use oxen. I wouldn’t burn up a horse doing that. Horses are transportation…

Non GMO seeds are going to be right popular, I expect…

The wicked flee when none pursueth..." - Proverbs 28:1