Fertilizing the lawn is an essential component of proper turf management. Apply fertilizer regularly to increase grass density, improve color and prevent the appearance of weeds and lawn disease. Test the pH of the yard's soil before fertilization to determine what kind of fertilizer you need to use in your lawn. You must also have a fairly accurate idea of the square footage of your lawn to determine the correct amount of fertilizer to purchase, and the proper broadcast setting when using a lawn spreader.
Take a sample of dirt from your lawn that is 4 to 6 inches deep from 10 or more locations, and put the sample in a plastic container, according to University of Arkansas Extension. Send the sample to your local university cooperative extension for testing. The lab results will come back with recommendations on what kind of fertilizer to use in your yard for best results.
Determine the size of your lawn by taking measurements using a tape measure. Multiply the length times the width of the measured area to determine the area. Fertilizers are applied based on 1,000-square-ft. measurements, notes the University of Arkansas Extension.
Core aerate the lawn using a hand-held aerating tool, or rent a gas-powered aerator if your yard is large. Aeration removes plugs of dirt from the yard, which improves water flow and will increase the effectiveness of applied fertilizer. Run an aerator in two directions for the best results.
Calibrate your spreader before applying the fertilizer to the lawn suggests Virginia Cooperative Extension. Place fertilizer into the spreader and place a bucket or bent piece of plastic or cardboard under the spreader to catch the fertilizer as it comes out. Push the spreader over a 100-ft. square, then weigh the fertilizer caught under the spreader. Multiply the weight by 10 to determine how much fertilizer you need per 1,000 square ft.
Apply half of the fertilizer in one direction, then spread the other half crossing the lawn in another direction to prevent over fertilizing in any one area, according to University of Arkansas Extension. Rotary spreaders throw granules 3 to 5 feet on each side of the spreader. Overlapping ensures the best coverage. Turn off the spreader at the edge of the lawn to prevent fertilizer waste.
Lightly water the lawn with 1/4 inch of water after the fertilizer is applied to reduce fertilizer run off. Watering also activates the granules.