Before we talk about the pros and cons of going to an ag school, let's tak about why you want to do it. Do you have an agricultural background? Flying the airplane is maybe 15% of my job. The rest is knowing my chemicals and crops, and what my swath is doing. Nothing wrong with going to a school if you need ratings and tailwheel time, but I would advise going and finding an operator and volunteering to work as ground crew loading and mixing before I tried to get a seat.
It's easier to teach a farmer to fly than it is to teach a pilot to farm. Not saying it's impossible to get into, but it's not getting any easier.