From the Rows: How to Pull a Corn and Soybean Sample

August 17, 2012 10:32 AM

From the Rows - Chip Flory - How to Pull Corn and Soybean Samples

Your chance to participate in Crop Tour from home!

While we're scouting fields across the Corn Belt Aug. 20-23 on the Pro Farmer Midwest Crop Tour, you can participate with your own personalized corn data via the Pro Farmer Virtual Crop Tour. Starting Aug. 17, you will be able to access the Virtual Crop Tour page on This will help you compare your yields to potential yields from across the Corn Belt and it will help us get a deeper understanding of the U.S. corn crop in a year full of uncertainty.

In each corn field -

Crop Tour scouts will get past the end rows and march 35 paces down the main rows. This helps preserve the randomness of plot selection.

- At the 35th pace, lay out a 30-foot plot and count all the ears that will make grain on two 30-foot rows.

- From one row, pull the 5th, 8th and 11th ears to include in the yield sample. These could be the three best, or worst, ears in the field, but this gives us a consistently random process to select sample ears.

- Measure the length of grain (in inches, rounded to the nearest one-quarter inch) on each ear (don't measure blank cob).

- Count the number of kernel rows around on each ear.

- Record the row width in the field.

To calculate the estimated yield, take the average number of ears in 30-foot of row TIMES the average length of grain per ear TIMES the average number of kernel rows around; divide the total by row width:

(47 ears X 6.5 inches X 16.7 kernel rows)/30 inch row

This example gives you an estimated yield at that spot in the field of 170.1 bu. per acre.

Or simply go to and follow the link to the Virtual Crop Tour and enter your collected data there!

In each soybean field -

Go to a "representative spot" in the field. Measure one 3-foot plot. Count all the plants in the plot and randomly select three plants. Count all the pods on those three plants and calculate the average number of pods per plant.

- To calculate the number of pods in a 3'X3' square, multiply the average number of pods per plant by the number of
plants in the 3-foot plot. Multiply the number of pods in 3 feet by 36 and divide by row width:

(14 plants X 32 pods per plant X 36)/15 inch row

This example gives you 1,075.2 pods in a 3'X3' square.


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