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/1000 sq ft. You can use our fertilizer calculator at http://www.agry.purdue.edu/turf/fertcalc/Fertilization%20calc.html or you can use the handy table. If you chose to calculate it yourself, use the following two steps:
| Step 1. Calculating the amount of fertilizer/1000 sq ft: | ||||
| Desired rate in lbs N / 1000 sq ft | ÷ | % nutrient | = | Total fertilizer needed / 1000 sq ft |
| Step 2. Calculating the amount of fertilizer to treat the entire turf area: | ||||
| Total fertilizer needed / 1000 sq ft | X | Area to be treated in sq ft | = | 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 sq ft to an 8000 sq ft lawn?
| Step 1. Calculating the amount of 16-8-8/1000 sq ft: | ||||
| 0.75 lbs N / 1000 sq ft | ÷ | .16 N | = | 4.69 lbs 16-8-8 / 1000 sq ft |
| Step 2. Calculating the amount of 16-8-8 to treat the entire 8000 sq ft turf area: | ||||
| 4.69 lbs 16-8-8 / 1000 sq ft | X | 8000 sq ft | = | 37 lbs 16-8-8 needed to treat an 8000 sq ft lawn |
You’ll need 37 pounds of 16-8-8 to treat the 8000 sq ft lawn at 0.75 lbs N/1000 sq ft. More information of choosing fertilizers, fertilization schedules, calibrating spreaders, and more can be found in AY-22: Fertilizing Established Lawns.