# Calculate seeds per foot of row and seeds per acre

Proper calibration of seeding equipment requires that the operator be able
to calculate the number of seeds that will be planted per foot of row using
the desired plants per acre. It is often beneficial to calculate seeds per acre
from seeds per foot of row as well.

#### Equations

Seeds per foot of row = [seeds/acre]/43,560] x [row spacing/12]

where 43,560 is the square feet in an acre, row spacing is the distance
between two adjacent rows in inches; and 12 is the inches in one foot.

The equation above can be manipulated to calculate seeds per acre from seeds
per foot of row as well.

Seeds per acre = [43,560 x 12]/row spacing x seeds per foot of row

where 43,560 is the square feet in an acre, row spacing is the distance
between two adjacent rows in inches; and 12 is the inches in one foot.

#### Example problem

You are planting soybean in 15 inch rows and intend to plant at 200,000 seeds
per acre. How many seeds per foot of row will be planted?

Seeds per foot of row = [200,000 seeds per acre]/43,560] x [15 inches/12]

= 5.74 seeds per foot of row

You calibrate your planter to drop 6 seeds per foot of row. During a test run
you find that it is actually dropping 5 seeds per foot of row. If you do not
change the settings on the planter, what will be your seeding rate in plants
per acre?

Seeds per acre = [43,560 x 12]/15 x 5

= 174,240 seeds per acre

##### Agronomy 212 - Grain and
Forage Crops

Authored by Dr. Lance R. Gibson

Copyright © 1998-99, 2000-03 Iowa State University. All rights reserved.

Revised:
October 13, 2003
.