How much do you pay attention to the green space around you when you're strolling through your local neighborhood or suburbs? While the manicured lawn looks aesthetically pleasing, new research suggests that there is a more dangerous side behind these perfectly manicured green rectangles.
Lawns occupy an important part of the residential landscape, providing benefits for human health and well-being, as well as serving the environment. But in fact, these lawns are not necessarily greener. Multiple surveys conducted by a new study show that about half of U.S. homeowners use fertilizer on their lawns, and many lack understanding of the negative effects of nitrogen fertilizers.
The vast majority of people seem to just want their lawns to be thick, healthy and green, but many homeowners (about 60%) are unaware of the negative effects of such fertilizer use. Nitrogen from lawn fertilizers can enter waterways and harm ecosystems, including algal blooms and anoxic waters. The United Nations Environment Programme (UNEP) strongly recommends limiting nitrogen pollution as much as possible, as this has a negative impact on both human health and climate change.
In the Baltimore metropolitan area of Maryland, the team wanted to identify "hot spots" in suburban areas that had an uneven impact on nitrogen emissions in the region. Similarly, they are looking for "hot moments", which are times when nitrogen emission rates are high.
To do this, the team measured nitrogen emissions at three different lawn scenarios, including suburbs, campuses, and rural areas, with simulated rainfall events. They found that the areas that are responsible for the greatest emissions or nitrogen emissions – hot spots – come from where fertilizer is applied.
Survey respondents showed interest in retrofitting lawns to features that reduce nitrogen emissions, especially if the retrofit was subsidized and easy for homeowners. Some survey respondents even expressed interest in the restrictions on fertilizers, including those who had used fertilizer at home.
The team believes that retrofitting just 5 to 10 percent of a suburban lawn can have a significant impact on nitrogen emission levels. Other suggestions include using autumn leaves as a natural cover instead of initially introducing nitrogen fertilizer, and taking nine easy steps to improve biodiversity in your garden.
The study was published in the journal PNAS.