Great Plains 1520P Material Rate - Manual (Page 5)

12/1/2009 118-959B
5
Checking Singulated Seeding Rate
The seed charts are based on cleaned and sized
seed. Extreme seed size variations, foreign material
and tire pressure will affect the seeding rate. Check
the seed population rate as described below.
1. Adjust the planting depth to a shallow setting.
2. Plant at the desired planting speed for a short
distance.
3. Using the table, determine how many rows
need to be counted.
4. Measure a distance, according to the table, for
the row spacing in the planted area.
5. Count the number of seeds, in the appropriate
number of rows, over the distance measured.
6. Multiply the number of seeds counted by 200 if
measuring for 1/200 acre or by 1,000 if measur-
ing for 1/1,000 acre. This is the plant population
in seeds per acre.
Example 1: Single Row
If you have a 10-inch drill, according to the chart,
three rows must be counted. Measure 17’ 5” and
count the number of seeds in three rows. If the num-
ber is, for example, 180, multiply 180 by 1,000.
180 x 1,000 = 180,000 seeds per acre.
Example 2: Twin Row
If you have a Twin Row 30” spacing drill, according to
chart, both rows of the twin row must be counted. Mea-
sure 87’ 1” and count the number of seeds in the
parallel row. If the number is, for example, 170, multiply
170 by 200.
170 x 200 = 34,000 seeds per acre.
NOTE: Both rows of the Twin Row count as one row.
7. If the planting population is significantly different
than desired, make the following checks:
• Double check the transmission and range sprocket
combinations. Refer to the seed population chart
for the seed being planted.
• Check the air pressure in the gauge wheel tires.
Refer to “Tire Inflation Chart” in the operator’s man-
ual.
• Refer to Troubleshooting in the operator’s manual.
Seed rate charts
Seed rate charts begin on page 6. The charts give
transmission sprocket combination and drive range
sprockets for row spacing used, to achieve the popula-
tion or pounds per acre desired. The charts also give
seed spacing for singulated seed and maximum plant-
ing speed for both singulated and volumetric seeds.
Each seed chart has a corresponding page showing
the different drive ranges for that seed and a transmis-
sion sprocket reference.
Planted row spacing
(inches)
Number of
rows to count
Length of row
to measure
for 1/1,000
acre
Length of
row to
measure for
1/200 acre
7 1/2” 4 17’ 5”
9 1/2” 3 18’4”
10” 3 17’ 5”
15” 2 17’ 5” 87’1”
19” 2 13’9” 68’9”
20” 1 26’ 2” 130’8”
Twin Row 30’ or 30” 1** 17’ 5” 87’1”
Twin Row 36” or 36” 1** 14’6” 72’7”
Twin Row 38” or 38’ 1** 13’9” 68’9”
Twin Row 40” or 40” 1** 13’1” 65’4”
15” Skip Row or 17 1/7 2 15’3” 76’3”
**Count Twin Row as one row.
NOTE: USE 1/200 ACRE FOR POPULATIONS LESS THAN 100,000 SEEDS/ACRE.
USE 1/1,000 ACRE FOR POPULATIONS ABOVE 100,000 SEEDS/ACRE.