Appendix
Spreading rate calculation
2018-9015-001
09-2016
Flow rate formula:
Metric unit
Spreader volume ÷ spreading time = litres/minute
Example: 14550 litres ÷ 3 minutes = 4850 litres/minute
Imperial unit
Spreader volume ÷ spreading time = gal (UK)/minute
Example: 3200 gal (UK) ÷ 3 minutes = 1067 gal (UK)/min
Spreading rate formula:
Metric unit
Flow rate x 600 ÷ spreading width ÷ tractor speed = litres/hectare
Example: 4850 litres/minute x 600 ÷ 11.5 meters ÷ 9.6 km/h = 26359 litres/hectare
Imperial unit
Flow rate x 495 ÷ spreading width ÷ tractor speed = gal (UK)/acre
Example: 1067 gal (UK)/minute x 495 ÷ 38 feet ÷ 6 mph = 2316 gal (UK)/acre
Spreading rate versus spreading speed:
● Determine the proper spreading rate according to your application in order
to define the tractor speed;
● Apply the rule of three as follows;
Tractor speed x required spreading rate ÷ monitored spreading rate = new
speed
Example: 9.6 km/h x 20000 litres/hectare ÷ 26359 litres/hectare = 7.28 km/h
To spread 20 000 litres/hectare of manure, the driver must maintain the tractor
speed to 7.28 km/h.
Note!
Also read section Flow rate adjustment.