mjncad
Super Member
Is there a rule of thumb for disc harrow HP requirements? For example, 5hp per 1-foot of harrow width?
Depends on several variables: weight of the disc, depth of blade penetration, soil type, soil moisture. I use a heavy 6.5 ft wide offset disc and pull it with my 2008 Mahindra 5525 (55 hp engine, loaded rear tires, about 6500 lb tractor weight). YOu need to pull a disc at 5-6 mph to get it to work effectively. I have plenty of hp in dry soil. If the soil is wet, then the disc digs deeper and loss of traction is a problem. So my guess is you'll need 5-10 engine hp to operate a disc like this.