Fertilizer rate calibration – Great Plains 3P1006NT Material Rate User Manual
Page 35
Great Plains Manufacturing, Inc.
Fertilizer Rate
33
2011-10-21
151-144B
Fertilizer Rate Calibration
Differences will exist between the tested fertilizer and
field conditions used to generate the Rate Chart, and
your fertilizer and conditions. To accurately achieve your
target application, Great Plains recommends calibrating.
Perform the calibration with the drill hitched and raised.
Install lift-assist cylinder lock(s). Calibration with the drill
lowered is not recommended, as the drive tires in ground
contact prevent drive operation.
Due to the large number of crank revolutions per acre
(310 or 569) and per hectare (766 or 1405), a practical
calibration is a simulation of
1
⁄
10
th
acre or
1
⁄
10
th
hectare.
1.
Estimate the sample sizes.
2.
To perform this calibration, you need a scale that is
accurate near the aggregate sample size, and 3 light
weight containers, each capable of holding a row’s
sample.
3.
Raise the drill so the gauge wheel is out of ground
contact. Install cylinder lock(s).
4.
Remove the calibration crank from its storage stob.
Store the retaining pin on the stob.
5.
Place the hex socket of the crank at the left side
cranking shaft (see page 2).
6.
Pull the fertilizer hoses off the top of three openers,
at the top of the openers. Place the hoses into each
sample container.
7.
If not already done, make any density correction,
then using the chart for the target rate, set rate
adjuster. If seed is loaded, remove the drive chain for
the seed box (unless you are simultaneously
calibrating seed rate).
8.
Load fertilizer above the rows to be sampled. Load
well more than the expected sample size.
Possible Agricultural Chemical Hazard:
Follow material supplier recommendations for safety
precautions in handling fertilizer.
9.
Rotate the crank several turns counter-clockwise to
ensure that the drive and meters are engaged,
working properly, free from foreign material, and that
material is flowing steadily from the meters. Stop.
Example: You want to apply 109 pounds per acre, and
want to simulate
1
⁄
10
th
acre. RateSample is 10.9.
Example: SamplePerRow is 0.73:
Example: 3 rows are to be used in the sampling.
ExpectedSample is 2.18:
10.9
109
10
---------
=
0.73
10.9
15
-----------
=
2.18
0.73
3
×
=
RateSample
TargetRate
10
-----------------------------
=
SamplePerRow
RateSample
RowCount
------------------------------------
=
ExpectedSample
SamplePerRow
SampledRows
×
=
Example: 3 containers each weighing 0.5 lb
or 1.5 lb total
Crushing Hazard:
Install lift lock(s) on a raised drill.
See example on page 32, which determined an initial
rate adjuster setting of:
60