Harvest is well underway in Missouri. For many farmers, fertilizer spreaders soon will follow in the fields. But just how even is your application?

Peter Scharf, University of Missouri Extension nutrient management specialist, and his MU colleague Larry Mueller are testing the spread pattern of spinner machines this fall, and they need farmers to participate.

For many Missouri farmers, fall fertilizer is part of their postharvest routine. It is a way to replenish fields with phosphorus and potassium taken up from the soil by the crop. And, Scharf says, most farmers will apply fertilizer using a spinner spreader.

This type of applicator can cover a lot of acres quickly. However, Scharf says, the main issue with spinner spreaders is the potential for uneven applications of fertilizer.

“Over the past few years, we have tested a number of spinner spreaders with catch pans and have found that it's fairly common for the spread pattern to be less than what you'd want,” he explains in an MU Integrated Pest Management Newsletter article.

He offers the following graph to show just how variable the coverage from a spreader spinner can be. It depicts the spread pattern on average for two tests:

Scharf says there is no good way to verify that these types of machines are spreading the pattern farmers want except to catch the fertilizer and weigh it. So, he and Mueller want to do just that in Missouri farm fields.

The two are running a test program, funded by the Missouri Fertilizer Board, to determine the spread pattern of spinner spreaders and verify that they are right, or, he adds, “help people to get them right.”

If you would like to have the spread pattern tested for your machine or in your fields, text Scharf at 573-808-5396 or Mueller at 573-289-1748 to set up a time.

University of Missouri Extension contributed to this article.