Turfgrass research yields surprise
How fertilizing your lawn can improve the environment
A fertilized lawn may help you compete with the neighbors when it comes to curb appeal, but did you know it also has important environmental benefits?
University of Minnesota research is helping us discover that healthy, fertilized lawns—once viewed as polluters—can benefit soil and water quality if fertilizer recommendations are followed.
A five-year Extension study examined the amount and quality of runoff from test plot lawns with various levels of fertilizer used. Results showed that unfertilized lawns resulted in greater phosphorus runoff than lawns kept healthy with fertilizer treatments.
"Homeowners sometimes think fertilizer is bad for water quality, but our research shows that's not always true," explains Brian Horgan, Extension turfgrass specialist and one of the study's authors. "The health and density of the lawn was what made the difference, and good fertilization practices create healthier, denser lawns."
The longest-running study on turfgrass runoff in the Upper Midwest, University research showed that 80 percent of the runoff occurred during the winter, when soils were frozen.
Healthy turfgrass can improve surface water by stabilizing soil against water and wind erosion and reducing runoff. It can improve groundwater by filtering water as it passes through and using microorganisms in the root zone to break down contaminants. The infiltration process also helps recharge groundwater supplies, according to Horgan. Other factors influencing water quality include how compacted soil is and what species of turf is used.
The results of this study are informing the Minnesota Pollution Control Agency's update of stormwater best management practices. For the first time, a healthy lawn may qualify as a stormwater credit.
Lawns that contribute to slowing runoff and filtering water mean cleaner lakes, rivers, and drinking water for Minnesota. And competing with the neighbors? Well, appearance shouldn't be the basis for judging your lawn's level of environmental friendliness, Horgan cautions.
"Grass doesn't have to look green all the time to be healthy. It's very hard for homeowners to accept that with our 'Keeping Up With the Joneses' attitude."
For more lawn-care research and resources, visit Turfgrass.
According to Extension turfgrass research, a healthy lawn is an environmental asset because dense, growing grass prevents runoff and controls erosion.