Farmers tend to skimp on fertilizer when costs are on the rise. Proper fertilization, though, is necessary for quality pasture forage. Spreader calibration is a great way to save money and is a best management practice.
Spreader calibration assists farmers in applying the exact amount of fertilizer while saving money and protecting the environment. Spreader calibration is considered a best management practice because it helps reduce the over application of nutrients. When nutrient over-application occurs, farmers lose money and the additional nutrients can end up in runoff water after a rain.
Weight Per Area Calibration
The preferred method for calibrating any fertilizer spreader is the weight per area method. In the weight per area method the spreader is loaded with fertilizer and then weighed. A pass-through of a pre-measured 10 by 100 foot area is conducted and the spreader is then weighed again to determine how much fertilizer per 1,000 feet was used. This amount is then translated to how much fertilizer per acre would have been used. Farmers then know how much fertilizer was spread per acre and they can make adjustments to either increase or decrease the amount of fertilizer spread.
Weight Per Tarp Area Calibration
Conducting a pass-through is not the only available option when using the weight per area method. The alternative is to use a securely anchored tarp of known size and empty weight. A pass over the tarp is made at the desired fertilization pace and spreader setting. The tarp is weighed with the fertilizer after the pass-over. A determination is then made as to how much fertilizer was distributed per tarp area. The weight per tarp area is then translated into the amount per acre. Again, the fertilization speed and spreader delivery setting allows the farmer to make adjustments to fertilization rate which will save money and protect water quality applying only the fertilizer needed.
Soil Tests
Another tool to use in determining how much fertilizer to apply is a soil test. A soil test provides information on the nutrient levels of a particular field. For example, soil test results provide information as to which fields may need more or less potassium in the form of pot-ash. If the same rate of pot-ash is applied to all pastures then some may get to much while others might not get enough resulting in costly and inefficient fertilizer use. The soil test also aids farmers in efficient application of fertilizer since only the amounts needed are recommended to be applied.
For more information on fertilizer spreader calibration, best management practices or forage management, contact your local extension office.
John Pennington is a Washington County Extension Agent with the University of Arkansas Division of Agriculture, specializing in Agriculture and Water Quality.
