Calibration of Seed Drill
Determining Normal Width of Seed Drill
Determine the nominal width of coverage of the drill.
Nominal width = Number of furrow x distance between furrows
e.g. A nine furrow drill with furrows spaced at 25 cm
25 x 9 = 225 cm = 2.25 m
Determining Length of Strip
After getting the nominal width value let uscalculate how much
length needs to be traveled to cover 1 ha with this drill.
e.g. 10000 m 2/2.25 m = 4444 m ~ 4500 m approx
Determining revolutions of ground wheel
To find the number of revolutions that the ground wheel will
make to cover the length of strip.
Circuimference of wheel = Pi (22/7) x Diameter of wheel = 3.14
x 0.6 m ~ 1.8 m
1.8 m = 1 revolution
4500 m = 4500 / 1.8 = 2500 revolutions
Determining Revolution of Ground Wheel
To find the number of revolutions that the ground wheel will
make to cover the length of strip.
Circuimference of wheel = Pi (22/7) x Diameter of wheel = 3.14
x 0.6 m ~ 1.8 m
1.8 m = 1 revolution
4500 m = 4500 / 1.8 = 2500 revolutions
PY13032UN03OCT11
Revolution of Ground Wheel per hectare
Determine the number of revolutions of ground wheel to convenient
fraction of a hectare, say 0.25 hectare.
e.g. A drill having a nominal width of 2.25 m and ground wheel
diameter of 60 cm will require about 500 revolutions to cover 0.25
hectare.
Revolution of Ground Wheel per minute
For calculating the revolutions of ground wheel per minute,
let us take an example.
Calculate revolutions per minute of ground wheel at a speed
of 35 km/hr.
e.g. A 60 cm diameter wheel makes about 30 revolutions per minute
when traveling at a speed of 4 km/hr.

Mark on ground wheel to validate the calculations.

Select and fill the seeds and fertilizers.

Place plastic bag or container at the end of each seed &
fertilizer tube & collect it.

Record the weight of seeds and fertilizers dropped with respect
to the positions of levers.

Determine the weight of the total seeds and fertilizer collected
separately.

Calculate the seed rate i.e. weight of seeds in kg per unit
area in hectare.

RP90046,00007D11920111003

