Nitrogen's Effects on Grass

Nitrogen Application for Lawns

• Nitrogen increases the top growth of plants. The more nitrogen applied, the thicker the grass. However, according to a fact sheet by the Ohio State University Extension, too much rapid growth can become a mowing nightmare and increase disease susceptibility. Instead, nitrogen application should be limited to very little during the spring and summer and increased during late summer and fall. Fall nitrogen application stimulates deeper root growth and an overall healthier plant.

Types of Nitrogen

• Nitrogen fertilizer should contain water insoluble and water soluble forms of nitrogen. Water insoluble nitrogen works slower, providing nitrogen over a longer period of time and giving a more consistent growth to the grass Water soluble nitrogen releases quickly into the ground, providing a quick growth.

Nitrogen Application for Pastures

• Grazing animals on grass pastures reduces the overall amount of applied nitrogen. Over 80 percent of the nitrogen consumed by grazing animals returns to the pasture as urine and feces. Moreover, Cuomo recommends waiting until mid-June to apply nitrogen to pastures. Nitrogen application in mid-June will stimulate growth for fall forage grazing.

Types of Nitrogen for Pastures

• Replenishing nitrogen in pasture grass, can by done through livestock manure fertilizer and by growing legumes with the grass. Legumes will replenish the soil with 80 to 100 pounds of nitrogen per acre, according to Cuomo. Livestock who feed on the legumes will return approximately 80 percent of that nitrogen back onto the pasture.