Great Plains 1520P Material Rate - Manual (Page 4)

118-959B 12/1/2009
4
Checking Volumetric Seeding Rate
The seed charts are based on cleaned seed and
9.5L x 15, rib implement tires. Factors including
foreign material, seed treatment, seed size, seed
weight, field conditions and tire pressure will af-
fect 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.
3. Raise drill off ground.
4. Turn gauge wheel a few turns to fill meters
with seed and until seed drops to ground from
all three openers.
5. Place a container under the three openers to
gather seed as it is metered.
6. Using the chart on the right, select your row
spacing and determine the correct number of
revolutions per acre. Turn drive gauge wheel
the selected revolutions for your row spacing.
Check in box to make sure seed tubes have
plenty of seed covering them.
7. 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.
8. 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 Troubleshooting in the operator’s
manual.
9. Readjust transmission and/or range sprock-
ets and repeat test.
Checking Seeding Rate
Planted Row
Spacing (Inches)
Number of
Rows
Tire
Revolutions
per Acre for
15ft drills
7.5” 24 365
10” 18 365
10” 19 346
15” 12 365
15” 13 337
20” 9 365
20” 10 329
30” 6 365
Twin Row 30” 12 365
Twin Row 30” W/S 19 346
Equations for calibrating volumetric seeding rate:
measured seed - empty container
3 (number of meters measured)
pounds per meter number of openers × pounds per acre =
= pounds per meter