I was reading other commenters mentioning the relatively old age of farmers. Maybe the only good option would be something like removing/phasing out existing subsidies so that only right amount of young people choose the profession coupled with a generous retirement program. Something like social security plus but with your farmland backing the plus part. Maybe in the spirit of what you’re describing. I worry about the unforseeable consequences of paying to leave arable land fallow. You’re essentially raising food prices and that really affects poor people the most.