What Are the Benefits of Slow Release Nitrogen Fertilizer on Grass?

Nitrogen

• Grass uses nitrogen to create amino acids, nucleic acids and chlorophyll. Plants need chlorophyll to perform photosynthesis, the process of converting sunlight into energy. Grass and other plants will die if they don't have any nitrogen. Most soils contain some nitrogen, but lawns usually need more nitrogen than exists in the soil. If grass doesn't have enough nitrogen, it may grow too slowly, appear yellow, grow thinly or be more susceptible to diseases. Slow-release nitrogen fertilizer provides nitrogen for your grass.

Benefits

• Slow-release nitrogen fertilizer helps your grass grow thicker and greener, giving it a healthier appearance. Slow-release nitrogen fertilizer lasts longer in your grass than quick-release nitrogen fertilizer, improving the color and growth of your lawn for months. Slow-release nitrogen fertilizer is also less risky than quick-release fertilizer, because it's less likely to burn your lawn or leach into groundwater.

Ingredients

• Slow-release nitrogen fertilizer may contain synthetic forms of nitrogen, such as isobutylidene diurea, polymer coated urea, sulfur-coated urea or urea-formaldehyde. Some types of slow-release nitrogen fertilizer also contain manure, activated sewer sludge or other organic products. Inorganic forms of nitrogen are only used in quick-release fertilizers. The first number in the N-P-K ratio on the fertilizer package lists how much nitrogen the fertilizer contains by weight. For example, a fertilizer labeled 16-0-8 contains 16 percent nitrogen.

Recommendations

• Apply 1 to 4 lbs. nitrogen per 1,000 square feet of grass each year, divided into one to four applications. High-maintenance, quickly-growing lawns require more nitrogen than low-maintenance lawns. Leaving grass clippings on the lawn instead of bagging them also helps add nitrogen and other nutrients back to the grass. Don't overfertilize your lawn; too much nitrogen will cause excessive growth, shallow roots, susceptibility to disease and low food reserves. Soil tests for nitrogen aren't very reliable, but performing a soil test can help you identify whether your lawn needs other important nutrients, such as phosphorus or potassium.