THANKS FOR THE RESPONSE. TIMELY.
The numbers I have for oil production from industrial hemp (Cannabis sativa) result from similar amounts of fertilization, irrigation, pesticides, and whatnot as the other crops. Hemp will grow without fertilizer, irrigation, pesticides, and whatnot (like all plants), but not nearly as well and with a massively reduced yield (especially seed oil yield).
USED FOR COTTON.
But we are not discussing cotton or other fiber crops. We are discussing energy crops. Industrial hemp is a very good fiber crop. If you want to make cloth or paper, industrial hemp would be a very good idea (if it were legal). However, industrial hemp is a poor energy crop. If you want to fuel your car, grow rapeseed or something better.
THE MULTIPLE USE FACTOR FOR FUEL OIL IS JUST ONE OF THE PLUS ITEMS.
Now if you're talking about taking the extra seed byproduct from growing hemp for fiber and putting it into a general oil seed feedstock for producing energy, then there's nothing wrong with your position. However, the low oil energy per acre output for hemp (especially compared to it's high fiber per acre output) means it will never be more than a tiny blip in any renewable energy economy.
If you're advocating growing hemp specifically as an energy crop, there are many significantly better energy crops out there.