Well, the felons never stop being prisoners in the time they work. This tends to result in an unmotivated workforce no matter what the activity. No only this project but most prison labor projects fail.
I'm unable to locate a resource indicating the pay, only a blurb that says prisoners must pay for their transportation (I'm sure that isn't marked up or anything...) and the pay rate must be at least minimum wage.
I'm guessing pay rate is a big part of the prisoners lack of enthusiasm.
Well, prisoners are unskilled and keeping them supervised while working is a significant expense, so the net value they yield is going to be very low.
Clearly, being a farm worker isn't a career path for the prisoner so the prisoner has no motivation to learn the intricacies of the job. And farm work turns out to have many intricacies. So yeah, this project seems impossible.
I'm guessing pay rate is a big part of the prisoners lack of enthusiasm.