How do you calibrate a granular spreader for turf to deliver the labeled rate per 1,000 square feet?

• A. Determine the spreader setting to deliver the labeled pounds per 1,000 sq ft, calibrate by weighing the product released over a measured area, adjust as needed
• B. Use the maximum spreader setting and apply
• C. Ignore calibration and apply by eye
• D. Calibrate by counting drops per square foot

Answer: (A)

Calibrating a granular spreader means setting it so it delivers the exact amount shown on the label for a defined area, usually per 1,000 square feet, and then confirming that the actual output matches that rate. To do this, pick a measured area and run the spreader while collecting the product that comes out. Weigh what was dispensed and calculate the rate per 1,000 square feet using the formula: rate = (weight dispensed) × (1,000 / area tested in square feet). If the result isn’t equal to the labeled rate, adjust the spreader setting and repeat the test until the measured output aligns with the label. This method ensures uniform coverage and accurate application, rather than guessing or relying on the widest setting or visual estimation. Using the maximum setting or applying by eye would likely over- or under-apply, and counting drops per square foot isn’t a practical method for granular products.