Don’t leave money on the table in seed

Think you may be dropping too many or too few soybean seeds per acre? You can do two things: First, put out a replicated trial. Second, do simple calculations that illustrate how much you might save in seed costs if you’re still planting at relatively high rates.

Key Points

• Fields with multiple soil types may require variable-rate seeding.

• Find the most uniform, representative field possible for conducting a trial.

If you can cut seeding rate and maintain yield, you can save thousands of dollars!

Traci Bultemeier, accounts manager for Pioneer Hi-Bred, Fort Wayne, and an Indiana Certified Crop Adviser, believes in on-farm trials, but only if the trials are replicated and set up correctly. Otherwise, too many factors can influence the test results.

Factor in soil type

“Depending on where you are in the state, even a small-acreage field can have three or more soil types,” Bultemeier says. “Many fields in northeast Indiana have eight or more in one field, ranging from heavy clay to blow sand to muck, all within a few yards of each other!

“Your soil type and corresponding tillage or no-tillage practices will have an impact on your ideal seeding rate due to stress emergence issues, including seedling blights, crusting and wet feet. Variable-rate seeding takes many of these factors into account when a prescription is written.”

The first step to conducting a successful on-farm trial is to learn how many acres the trial requires, Bultemeier notes. Then it’s time to factor in soil differences.

“My recommendation would be to find a uniform site that would be representative of the majority of your soil types,” she says. “Since this could be difficult, you can enhance your learning by harvest mapping the trial and using a soil overlay map to determine if there are any variances in performance of the seeding rate as soil type changes.”

Bultemeier also strongly recommends using a weigh wagon for individual comparisons. She believes harvest maps should only be used to determine performance over variable soil types.

Dollars add up

Here’s the payoff, perhaps the reason for going to such lengths for a trial. Dan Ritter, Newton County Extension ag educator and also a CCA, uses this example: The Purdue University Corn & Soybean Field Guide suggests a planting rate of about 160,000 seeds per acre for a final stand of near 130,680 plants per acre.

If you determine through plots that you could shave the rate and save 10,000 seeds per acre, here’s how much money you could save.“If you plant 1,200 acres of soybeans, you would save 85 units of seed at $50 per unit,” Ritter notes. That’s assuming an average price for Roundup Ready seed.

“It’s a four- to five-hour investment [to put out a test plot] worth $4,250,” Ritter says. “There are times when the information you gain won’t be as profitable, and there are times when it will be even more profitable.“You won’t know unless you’ve done the research and done it correctly,” he concludes.


Too many or just right?: On-farm trials could help you determine if you need this many plants per acre. If not, you could save money by decreasing seeding rate.

This article published in the March, 2012 edition of INDIANA PRAIRIE FARMER.

All rights reserved. Copyright Farm Progress Cos. 2012.