Visited this farm twice now. It is an impressive operation.
I work(
volunteer) almost full time at a CSA farm www.AnandaValleyFarm.org and we are trying to emulate Paul & Elizabeth's methods, in a similar climate.
What they have done is very innovative in it's practicality.
Like many smaller market farms they rely on growing many different types of vegetables for a CSA direct to consumer retail pricing.
A lot of work, but a method smaller farms can compete with larger mechanized ones while giving people fresher, healthier food.
Their profitability probable exceeds large farms when looking at profit/acre, profit/capital investment. Profit/man hour is probably less though, but this means they employ more labor and employ less machines.