Agronomy 212 - Grain and Forage Crops

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

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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 .