Tom, there is no one answer to your questions due to many variables. However our Pluribus and 6000 units both take no more than about 15 hp per row. I used to say 10 hp per row but that was when folks tended to travel at 6 mph. The systems work well at 7 or 8 mph where you have terrain and conditions (few rocks) and that ups the hp to the 15hp/row range in some conditions.

Don't forget the hp just to haul 10-12 tons of fertilizer up a hill at 8 mph. And the fan on a dry cart at high speeds and flow rates can take in the range of 40 hp, usually hydraulic. I would talk to Roger Montag about those numbers however.

Tom, A real nice system is an MFWD 250 hp range tractor with a 12R30 vertical fold 3 point tool with Gnuse hydraulic top link and a Montag cart. This will have the 3-point lift capacity and a bit of hp as insurance. Here is an older video of an eastern Iowa customer with this type system. He is using a Moore-Built toolbar out of Benedict, NE (just north of York) very heavy duty and moderate cost. This system would probably work well with the 6000 also as long as there was a bit of weight from the cart on the toolbar for higher air pressures in harder ground.

Montag does make a 3-point lift assist version of his air cart which may let you use a slightly smaller tractor. However in NW Iowa hills I would not underestimate the weight nor hp for safe road transport and operation at the higher speeds you will want to run once you get the RTK and system going. Roger can tell you more about the cart requirements.

Jim at Dawn

the Case 8950 on the 24 row system in the photos above is listed at 225 hp but it needs the aux power for the cart fan and is speed limited to about 6-7 mph when the cart is full.