There are a half-dozen US correctional facilities that have prisoners learning crop/food production skills. I don’t think it will ever be mainstream. You need non-violent offenders, healthy enough and safe enough to use tools. Land that can be secured — securely fencing acres of land is costly.
Then there is the question of: do the prisoners want to do this — physically can they? Will they become modern-day slaves on prison plantations? How many farmers can the economy provide jobs to once they leave prison? Couldn’t they already get low-wage farm jobs without on-the-job training provided by the corrections facility?
Yes, in the right environment, this is a great plan. You need the right land, the right climate and the population that fits this approach. Sometimes I think we just need fewer prisons.