In McBain Michigan we have a couple custom manure haulers and corn choppers and I work for them a little bit part time and they have 19 Quad Axle manure spreaders and about 20 1042 fendt tractors, trust me it's a lot of fun but you got to know what you're doing
how much manure do you spread? 15.000 gallons per acre? In German we are limited at 170 kg nitrogen/hectar or 68 kg n/acre. That leads to 3.600 gallons per acre