CALIBRATION
For field applications of fertiliser, sprays etc:
g/litre—parts/million (ppm): multiply by 1000
g/litre—ounces/Imperial gallon: multiply by 0.160
g/m^2 —oz./yard^2 :divide by 33
kg/ha—lb./acre:multiply by 0.892
22
lb./acre—kg/ha:multiply by 1.121
miles/hour (MPH)—km/hour: multiply by 1.6
How to Determine Miles per Hour (MPH) using a tractor:
- With two stakes, mark out a distance of 26.8 metres.
applying fertiliser etc.
stopwatch.
km/hour, multiply by 1.6.
Converting Spray Broadcast Rate to Row Basis
Instructions for applying sprays, and sometimes fertilisers, are often only given for
coverage of the entire surface area. But if the chemicals are to be applied in bands, ie
along the plant row only, then the actual amount of solution to use per hectare can be
calculated by using this formula:
Broadcast Rate (litres/ha) multiplied by
[the Band Width (cm) divided by the Row Spacing (cm)].oz./yard —g/m :multiply by 33
GROWING FOOD – THE FOOD PRODUCTION HANDBOOK 315
To convert: into
- Select the gear and accelerator setting of the tractor to be used when spraying, or
- From a running start, measure the time taken to cover the 26.8 metres, using a
- Divide 60 by the time in seconds. This gives the speed in mph; to covert into