1) Determining the rate of fertilizer per 1,000 sq. ft. based on Nitrogen needs:

Divide the pounds of Nitrogen you need by the percent Nitrogen in the formulation to get pounds of fertilizer you need per thousand sq. ft.

Example: 25-2-4 fertilizer needs 0.80 lb. Nitrogen per thousand.

0.80 lbs. Nitrogen required / 0.25% Nitrogen in fertilizer ~ 3.2 pounds 25-2-4 per 1,000 sq. ft.

__lbs. N / __% N = __lbs. per 1,000 fertilizing material to apply.

2) Find an open area, at least 50 feet long and get a bucket, calculator, tape measure, scale and 25-2-4 fertilizer to be calibrated.

3) Estimate the amount of 25-2-4 you will need for the test and place it in the spreader.

4) Set the spreader at the setting suggested on the bag for your spreader. This is a suggested setting only. The condition of your spreader (age and specific variations in your model) will cause differences in the actual setting and the suggested one.

5) Spread the material along the open area you have chosen. Walk at the pace you normally will during actual applications in yards. Many spreaders are dependent on walking speed along with spreader settings. Start your walk before your measured start point to ensure accurate calculations.

6) Weigh the amount of material left in the spreader.

7) Measure the length and width of the area covered. Calculate this into sq. ft. (length x width).

8) Calculate the amount applied per 1,000 sq. ft.

Example: 4.0 lbs. applied on 500 sq. ft.

2.0lbs. x (1,000 sq. ft. / 500 sq. ft.) = 4.0 lbs. applied per 1,000 sq. ft.
__lbs. x (1,000 sq. ft. / __sq. ft.) = __lbs. applied per 1,000 sq. ft.

9) Adjust the spreader setting to adjust your rate to spread less material and repeat the test process to spread 3.2 lbs. fertilizer per 1,000 sq. ft. (to apply 0.8 pounds Nitrogen per 1,000 sq. ft.).
10) Factors that affect spreader settings include walking speed, differences in granular size, moisture content of granules, coatings (such as Team Pro®), age and condition of spreader, amount of overlap and other similar conditions.