by David Salman
Lawns are a mainstay of American landscapes. But traditional lawn care and maintenance methods are an ecological nightmare. American gardeners and landscape professionals need to make a concerted effort to make our lawns more eco-sensible.We can do this by:
- reducing the amount of area covered by turf and use more groundcovers where appropriate
- select regionally appropriate native and “low mow” lawn grass varieties
- use only organic/natural fertilizers and soil amendments to restore the soil’s health and slow the rampant growth that results from the use of high nitrogen chemical fertilizers.
The following excerpt from the most recent issue of sciencedaily.com will be quite startling to most folks.
ScienceDaily (Jan. 22, 2010) — Dispelling the notion that urban "green" spaces help counteract greenhouse gas emissions, new research has found -- in Southern California at least -- that total emissions would be lower if lawns did not exist.
Turfgrass lawns help remove carbon dioxide from the atmosphere through photosynthesis and store it as organic carbon in soil, making them important "carbon sinks." However, greenhouse gas emissions from fertilizer production, mowing, leaf blowing and other lawn management practices are four times greater than the amount of carbon stored by ornamental grass in parks, a UC Irvine study shows. These emissions include nitrous oxide released from soil after fertilization. Nitrous oxide is a greenhouse gas that's 300 times more powerful than carbon dioxide, the Earth's most problematic climate warmer.
"Lawns look great -- they're nice and green and healthy, and they're photosynthesizing a lot of organic carbon. But the carbon-storing benefits of lawns are counteracted by fuel consumption," said Amy Townsend-Small, Earth system science postdoctoral researcher and lead author of the study, forthcoming in the journal Geophysical Research Letters. The research results are important to greenhouse gas legislation being negotiated. "We need this kind of carbon accounting to help reduce global warming," Townsend-Small said. "The current trend is to count the carbon sinks and forget about the greenhouse gas emissions, but it clearly isn't enough."
Turfgrass is increasingly widespread in urban areas and covers 1.9 percent of land in the continental U.S., making it the most common irrigated crop.
This research emphasizes yet another big reason why it is imperative that we:
- Stop the use of chemical fertilizers and toxic herbicides, fungicides and other lawn chemicals and
- Plant native and improved dwarf “low mow” turf grass varieties that don’t require intensive mowing and maintenance.