Dr. Dan Talks Agronomy

Learn to Map Your Corn Stands

Dan Davidson
By  Daniel Davidson , DTN Contributing Agronomist
Almost all the corn in this central Illinois corn field emerged the same day and that leads to a more uniform stand and higher yield. (DTN photo by Pam Smith)

Many of you pay a lot of attention to your planter and how it singulates seed and places it properly in the soil, and you are very aware of the soil conditions necessary for optimal emergence. But are you taking the time to see how your corn plants respond to your management?

We all know the runts in a litter of pigs typically don't gain as well as the stronger piglets surrounding them.

The same is true of corn stands. Plants that emerge later or come up too close together will consume resources and often produce a smaller ear or sometimes, no ear. They tend to become the runts of the row and do little to achieve yield goals. Our goal is to have every seed emerge at the same time, look the same and produce the same size of ear.

We all should know the basics of getting a good corn stand, assuming the seed is viable and vigorous, include seeding into the right soil conditions, with favorable weather conditions for five days ahead and running a finely tuned planter.

What's so important today is the available planter technology that improves planting performance includes changing down pressure, sweeping trash away from the row, singulating seed in the furrow, preventing seed bounce in the row, firming the soil around the seed and fracturing the sidewall after closure to prevent compaction. But we can't rely on technology to do it all for us.

Doing corn stand counts is a normal practice and tells you if you are close to your target population or if the population is low and you need to consider replanting. The process is simple and requires several measurements per field. Measure off the distance appropriate for your row width for 1/1000th of acre, count the number of live plants and multiply by 1,000 to obtain an estimate of plants per acre.

But this practice doesn't tell the whole story either. It's important to attempt to get those seedlings emerging at the same time.

Our farm neighbors in Stanton County, Neb. have been working on perfecting emergence and getting corn off to a good start for the past few years. I have been impressed that they take the time to tag rows of corn plants as they come up to check emergence timing and growth rate on bare soil, under residue, different rotations and planting dates. They have noticed a huge different in emergence, early growth rate and ear size. By doing this they have changed how they plant corn on their farm. Watching what they learned has also influenced how I plant on our farm.

They are now more sensitive to soil conditions, soil temperature and residue coverage. It has caused them to adopt a policy of waiting to plant corn until after mid-April when soil conditions are better and the weather forecast is more favorable three to five days out. They often wait for those perfect conditions by planting soybeans instead.

I hope more corn producers will take the time to check if their management of planting corn is helping them meet their emergence and stand goals.

Bob Nielsen at Purdue University has written on stand variability in corn and its causes https://www.agry.purdue.edu/….

Dan Davidson can be reached at djdavidson@agwrite

(PS/ES)

Dan Davidson