Great Plains 1205NT Operator Manual - Manual (Page 38)

1205NT
150-131M 3/28/12
36
Fertilizer Meter Rate
Fertilizer application rates will vary with fertilizer
type, density and particle size. Relative humidity
and field conditions can also affect application
rates. The chart on page 37 is based on material
with a density of 65 pounds per cubic foot (1.04 kg/
L) and average particle size. Initially set rate accord-
ing to the charts, then calibrate the drill to your
material as described below.
NOTE: For drills built after October 1, 2005, cali-
brate using gauge wheels or supplied calibration
crank. For drills built before October 1, 2005, cal-
ibrate using gauge wheels or order calibration crank
kit available through your Great Plains Dealer.
1. To calibrate using gauge wheels, raise drill with
tractor hydraulics so drive wheels are off the
ground. To calibrate using supplied calibration
crank, attach crank to coupler on gauge wheel
jackshaft with retaining pin. Disengage lockout
on the drive wheels.
2. Rotate drive wheels or calibration crank to see
that metering system is working properly and
free from foreign material.
3. From the chart on page 37, find the setting
number for your row spacing and desired appli-
cation rate. Rotate gate adjustment knob to the
number obtained from the chart.
The fertilizer rate chart is for granular fertilizer with a
density of 65 pounds per cubic foot (1.04 kg/L). If you are
applying fertilizer with a different density, use the density
conversion chart.
4. Check that gauge-wheel tires are the correct
size and properly inflated. Refer to “Tire Infla-
tion Chart”, page 61.
5. Record the weight of an empty container large
enough to hold fertilizer metered for one acre.
6. Place several pounds of fertilizer over three fer-
tilizer feed cups on outside end of drill box. Pull
fertilizer tubes off these three openers.
7. Turn gauge wheels or calibration crank a few
turns to fill feed cups with material. Continue to
turn until fertilizer drops to the ground from all
three tubes.
NOTE: You can also rotate the gauge wheel jack-
shaft by means of a wrench or socket. If rotating
gauge wheel jackshaft, disengage the lockout on
the drive wheel and use same number of rotations
as for rotating drive wheel.
8. Place a container under the three tubes to gather
metered fertilizer.
9. Turn gauge wheel or calibration crank for approxi-
mately 346 rotations (one acre). Check that the
three feed cups have plenty of fertilizer coming into
them.
10. Weigh metered material. Subtract initial weight of
the empty container. Divide by three. Multiply by
the number of openers on your drill to determine
total pounds-per-acre metered. If this figure is dif-
ferent than desired, reset adjustment knob accord-
ingly.
NOTE: You may want to repeat the calibration proce-
dure if your results vary greatly from the chart.
23386
1205NT Calibration Crank
Equations for calibrating seed rate:
measured seed - empty container
3 (number of seed cups measured)
= pounds per seed cup
pounds per seed cup x number of openers = pounds per acre