Calculating the pounds of fertilizer to apply
There are literally thousands of fertilizers and fertilizer/pesticide combinations available to homeowners and professionals. Therefore, we can’t recommend how many pounds of a specific fertilizer to apply, but rather we must recommend fertilization rates in pounds of nitrogen per thousand square feet or lbs N/1000ft2. You can use our fertilizer calculator at http://www.agry.purdue.edu/turf/fertcalc/Fertilization%20calc.html or you can use the handy table [PDF]. If you chose to calculate it yourself, use the following two steps:
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Step 1. Calculating the amount of fertilizer/1000 ft2: |
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Desired rate in lbs N |
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% nutrient |
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Total fertilizer needed |
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Step 2. Calculating the amount of fertilizer to treat the entire turf area: |
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Total fertilizer needed |
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Area to be treated in ft2 |
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lbs fertilizer needed to treat the area |
For example, how much fertilizer do you need to apply a 16-8-8 fertilizer at 0.75 lbs N/1000 ft2 to an 8000 ft2 lawn?
| Step 1. Calculating the amount of 16-8-8/1000 ft2: | ||||
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0.75 lbs N |
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.16 N |
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4.69 lbs 16-8-8 |
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Step 2. Calculating the amount of 16-8-8 to treat the entire 8000 ft2 turf area: |
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4.69 lbs 16-8-8 |
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8000 ft2 |
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37 lbs 16-8-8 needed to treat an 8000 ft 2lawn |
You’ll need 37 pounds of 16-8-8 to treat the 8000 ft2 lawn at 0.75 lbs N/1000 ft2. More information of choosing fertilizers, fertilization schedules, calibrating spreaders, and more can be found in AY-22: Fertilizing Established Lawns