Annually we spread millions of tons of insecticides, herbicides, fungicides, and fertilizer around homes to have the envy of the neighborhood – a perfectly green, weed free lawn. Interestingly, water quality suffers as excess nutrients from lawns are one of the largest sources of non-point pollution impacting water quality in our streams, rivers, lakes, and the Chesapeake Bay.
Penn State’s Center for Turfgrass Science estimates that Pennsylvanians maintain about 2 million acres of grass (about 7% of the state’s surface area) and 1.4 million acres of this are home lawns (about 5% of the state). About two-thirds of Pennsylvania is in the Chesapeake Bay watershed and contains an estimated one million acres of lawns.
There is a very strong link between land use and our water resources. Buildings, pavement, lawns, fields – human changes to the landscape – have affected natural water movement and water cycles Water now moves across the land and into streams in different ways and carries with it nutrients and other pollutants.
Most lawns are very poor at absorbing water. In fact, they are only a little better than pavement! Your lawn, because of grass root structure and soil compaction, can only absorb about 2 inches of water per hour compared to a forest that can handle 14 inches or more in the same amount of time. In the ideal scenario, water should not move across the land – instead, it should move into and through the soil.
Among all the different land uses, forests are best at managing water quantity and quality, rain or snow falling on forested land is more likely to percolate through the soil and in the process augment aquifers and control water flow into streams. As well, through this process, forest soils remove sediments and other pollutants. The fact that nearly 60% of Pennsylvania is forested is a real benefit to our water resources.
If you have a lawn and an interest in reducing its impact on water quality, consider participating in the Woods in Your Backyard Webinar Series. A principle focus of the webinar series is to learn about what happens to the rain and snow that falls on your land. This webinar-based education program will use a full-color, 108-page publication by the same title to guide you through the process of developing and implementing projects to enhance your land’s natural resources. For more information and to register, visit the Penn State Extension website or call 877-345-0691.