Great Plains 3N-3020P Material Rate - Manual (Page 4)

196-248B 12/1/2009
Great Plains Mfg., Inc.
4
Checking Seeding Rate
Checking Volumetric Seeding Rate
The seed charts are based on cleaned seed and
12.5 x 15, rib implement transport tires and 13 x
5.00 - 6 contact drive wheel tires. Factors includ-
ing foreign material, seed treatment, seed size,
seed weight, field conditions and tire pressure will
affect seeding rate. Set and check the seeding
rate, then readjust the rate as necessary.
1. Record the weight of an empty container
large enough to hold seed metered from three
meters for one acre.
2. Place several pounds of seed over three seed
meters on an outside end of the drill box.
NOTE: If drill box is full, shut off sliding seed tubes
to all but three meters on an outside end.
Refer to Figure 3
3. Turn contact drive wheel clockwise a few
turns to fill meters with seed and until seed
drops to ground from all three openers.
4. Place a container under the three openers to
gather seed as it is metered.
5. Turn contact drive wheel clockwise 420 revo-
lutions. Check to make sure seed tubes have
plenty of seed covering them.
6. Weigh measured seed. Subtract initial weight
of empty container. Divide by three for the
amount metered by each meter, then multiply
by the number of drill openers for the pounds-
per-acre seeding rate.
7. If seeding rate is different than desired:
• Double check transmission sprocket and
drive range sprocket combinations.
• Check for meter malfunction.
• Check for correct seed meter wheel.
• Check that all three rows are getting seed.
• Refer to the troubleshooting guide in the
operator’s manual.
8. Readjust transmission and/or range sprock-
ets and repeat test.
Equations for calibrating volumetric seeding rate:
measured seed empty container –
3 (number of meters measured)
----------------------------------------------------------------------------------------- pounds per meter =
pounds per meter number of openers × pounds per acre =
19114
Figure 3