Lawns are ubiquitous in the United States, and most homeowners fertilize their lawns at least once a year, usually with a high-nitrogen product. This has raised environmental concerns because fertilizer runoff can pollute waterways.
To help homeowners reduce their use of nitrogen fertilizer on cool-season grasses, researchers at Purdue University in Indiana tested eight different nitrogen fertilizer application rates on three different cool-season grasses -- Kentucky bluegrass, perennial ryegrass, and turf-type tall fescue. They wanted to determine which grass responded best to lower fertilization rates by evaluating characteristics such as dry matter yield, visual quality, canopy greenness, and disease susceptibility.
Although Kentucky bluegrass had better scores at higher nitrogen fertilization rates than the other two grasses in the study, turf-type tall fescue required less nitrogen input (less than 2.5 pounds nitrogen per 1,000 square feet per year) than Kentucky bluegrass to produce a lawn with acceptable visual quality and color and fewer disease problems. Perennial ryegrass required even more nitrogen fertilizer than Kentucky bluegrass to maintain its visual quality and color.
For more information about this study, go to: Agricultural Research Service.