Farm Progress is part of the Informa Markets Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them. Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Serving: IN

# A fact about crop yield you may not know

Amaze your friends with this crop yield brain-teaser, or use it to rethink how you apply inputs!

Sometimes facts are stranger than fiction. It's even true when it comes to crop yields and inputs. What you think you know because you've heard it repeated over and over again may not necessarily be fact.

Related: Longer Ears Could Send Yields Soaring in Corn Fields

Brian Denning, Justin Petrosino and Trevor Perkins, all agronomists in the Agronomy in Motion program for Stewart Seeds, Greensburg, threw out facts during a presentation to farmers at Columbus recently.

See if this one catches you off-guard. You may want to rethink some your input practices you follow with some of your most expensive inputs for crop production.

Question 1: How many bushels per acre can you add to yield per acre if each row on each ear is just one kernel longer?

Fact: Would you believe it's five to seven bushels per acre? Denning says it is, and notes that's why you can't afford to run out of nitrogen during pollination and grain fill. If one kernel aborts on each ear on each row, you lose five to seven bushels per acre.

Is he right? Here's an example using the standard formula for estimating yields with 80,000 kernels per bushel as the standard. You count 30 ears per 1/1,000th acre, with 16 rows of kernels and 38 kernels per row. In the next location the average is 30 ears with 16 rows, but 39 kernels per row. Here is the math:

(Based on Purdue University Corn & Soybean Field Guide): Spot one: (30 ears x 16 rows x 38 kernels =18,240 divided by 80) = 228 bushels per acre.

For spot 2: (30 ears x 16 rows x 39 kernels =18,720 divided by 80) =234 bushels per acre. Subtract 228 from 234 – that's 6 more bushels per acre for just increasing the kernel count per row by one kernel!

Even if corn is \$3 per bushel, that's \$18 per acre more gross revenue per acre. If it costs 10 more pounds of nitrogen at 47 cents per pound to get the extra kernel, that's \$4.70. You still net \$13.30 per acre. On 1,000 acres, that's \$13,300. That's real money!