Research by the University of Minnesota demonstrates that properly fertilized lawns have healthy root systems, which do a better job of holding soil in place than the root systems of non-fertilized lawns.
An unfertilized lawn loses its density and exposes soil, which leads to erosion and loss of nutrients. A fertilized lawn holds the soil in place, meaning less loss of nutrients and less phosphorus run-off. An unfertilized lawn actually has more phosphorus run-off than a lawn that is fertilized.
Brian Horgan, Ph.D., associate professor at the University of Minnesota and extension turfgrass specialist said, “If you don’t fertilize your lawn thinking you’re doing better, you’re actually doing a lot more harm than if you properly fertilize your turf.”