Crop Scene Investigation - 34: What happened to Karl's corn planter?

Tuesday, November 1, 2011

by BERNARD TOBIN

With the challenging planting conditions of spring 2011, Pioneer Hi-Bred agronomist Scott Fife knew it would only be a matter of time before he received his first call from a grower asking him for help with some strange happenings in a newly planted field.

Fife's first call to investigate came in late June from Karl, a Glengarry County farmer, who was trying to understand why his corn field featured an odd pattern – five short rows followed by one taller, knee-high row – that was repeated across the entire field.

From an agronomic perspective, nothing seemed out of the ordinary. "It was a really nice loam soil, very mellow and forgiving ground," recalls Fife. "It was tiled land that was chisel-plowed in the fall and cultivated in the spring."

The first thing Fife thought of when he visited the field was that there was a fertilizer problem. Maybe something was broken on the planter and the fertilizer was not delivered uniformly. The shorter plants may have been deprived of key nutrients during the early growing period.

The other consideration was planting depth. Was the slow-growing corn planted more or less deeply than the tall row?

When Fife dug up some of the slower-growing plants, he discovered that the seeds were set much shallower than the taller row which was planted at a normal 1.5 to two inches deep. Because of the shallow seeding, these seeds were deprived of crucial moisture. This, combined with dry weather following planting, produced the delayed emergence and slower growth.

Fife questioned Karl on how he cultivated the field. "If you work the field on an angle, it can cause valleys and sometimes your depth is affected, but we ruled that out because of the one row across the field that was not affected."

Fife then figured he would find the answer in Karl's six-row corn planter – all he needed was a closer look. What he found was a well-maintained planter. "There were no issues with fertilizer delivery – everything had been taken apart, oiled and greased. Karl had done a good job and other parts had been recently replaced, including one of the row units. The seed disc openers were new, as well as the seed tubes."

With no obvious solution to the short plant puzzle, Fife then asked Karl to hook the planter to the tractor and drive it in the yard to see if they could find an answer. "We couldn't really see any problems and we were getting frustrated. Then Karl stopped and lifted the planter off the ground. When I leaned down to get a closer look at the row units, I tried to spin one of the gauge wheels, but it was stuck."

Fife then asked Karl to run the planter again. He then noticed that the gauge wheels on five of the units would not spin without lifting up. The sixth unit appeared to work fine.
When Fife looked closely at the gauge wheels on the units in question, he discovered an inch and a half gap between the gauge wheel and the frame. When he tried to spin the wheels, they appeared to be jammed by mud that had packed into the gap. The wheel eventfully broke free and began to spin normally.

Do you know what was wrong with Karl's planter and what caused the uneven corn pattern? Send your solution to Better Farming at rirwin@betterfarming.com or by fax to
613-678-5993.

Correct answers will be pooled and one winner will be drawn for a chance to win a Wireless Weather Station. The correct answer, along with the reasoning followed to reach it, will appear in the next issue of Better Farming. BF