Spend some quality time with your fertilizer spreader
March 19, 2009 - Author: Fred Springborn, Michigan State University Extension, ANR Educator
Editor’s note: This article is from the archives of the MSU Crop Advisory Team
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The high cost of fertilizer this year has everyone looking for ways to use it more efficiently and to use no more than necessary. One way to be sure that you are getting the most for your fertilizer dollar is to apply fertilizer as uniformly as possible. Many farmers in Michigan and the Midwest still rely on various versions of the spinner spreader for granular fertilizer applications. This year it is important not to overlook the details. Such as, does the old spinner spreader apply fertilizer uniformly? Or could it do better?
A fairly easy way to check the spread pattern is to lay out six to nine or more greased boards in the field over the width of your intended spread pattern, spread over them, and observe the distribution of particles on the boards. If particle size and density of the fertilizer material is uniform, then particle distribution should be uniform on the boards across the spread pattern. Compare the outside, mid-points and center of the intended spread pattern.
The boards need to be large enough to collect enough particles at your application rate to be representative, 18-inches by 18-inches square pieces of plywood work well. The grease on the board will make the particles “stick” and not roll off the board. For most fertilizers such as potash or urea, a thin layer of black grease will work. You may want to use a different color of grease if using a dark-colored fertilizer, such as some of the byproduct Ammonium sulfate products. Why not just look at the ground? Crop debris, soil surface cracks, soil surface color and clods can make it difficult to see and compare particle distribution.
The most common spreading error encountered is improper overlap distance where the driver is too close or too far away from the previous pass resulting in strips of over or under application. Remember that different fertilizers have different particle sizes and densities which affect the rate of flow and distance of throw.
Other problems encountered include: improperly adjusted or worn fins on the spinners; bent dividers on double spinner spreaders, making application rates higher on one side of the spreader than the other; a bent and or sprung frame holding the spinner(s) at an unintended angle to the ground; and fluctuating rpm’s of the spinners, especially when the machine is traveling up and down slopes.
As with all of your planting and application equipment, check drive components such as bearings, chains and belts regularly to ensure smooth and consistent operation. Lubricate according to the equipment manufacturer’s recommendations and properly clean and store your equipment at the end of the season.
For more information on troubleshooting the spread pattern and adjusting your spreader, consult the manufacturer’s operator’s manual.
Editor’s note: For more advice about efficient fertilizer use, see our 2009 special issue at: http://www.ipm.msu.edu/fertilizer2009.htm