By Steve Noe
With growing concerns about our impact on the environment, we hear a lot of buzz these days about minimizing our “carbon footprint,” which is a “measure of the impact human activities have on the environment in terms of the amount of greenhouse gases produced, measured in units of carbon dioxide,” according to Wikipedia.org.
Well, contrary to what the California Air Resources Board and the Environmental Protection Agency might lead you to believe, lawn mowers and other lawn maintenance equipment actually do help reduce the carbon footprint, according to a turfgrass study recently conducted by Dr. Ranajit (Ron) Sahu, an independent environmental and energy expert and university instructor, on behalf of the Outdoor Power Equipment Institute (OPEI).
Sahu found that responsibly managed lawns sequester, or store, significant amounts of carbon, capturing up to four times more carbon from the air than is produced by the engine of a typical lawn mower. The findings are based on several peer-reviewed, scientific studies and models, where carbon sequestration had been measured in managed and unmanaged turfgrass.
“We were unsure about the study’s outcome, but existing data shows that a net carbon benefit exists from well-managed turfgrass such as the typical American lawn,” said Sahu. “When you take care of your lawn and promote a healthy root system, your lawn acts as a carbon sink, pulling and storing away carbon.”
The report, titled “Technical Assessment of the Carbon Sequestration Potential of Managed Turfgrass in the United States,” assesses the carbon benefit of well-managed turfgrasses that are cut regularly and at the appropriate height, fed with nutrients such as grass clippings, watered in a responsible way, and not disturbed at the root zone. Key report findings are as follows:
• Perennial managed grassland systems such as turfgrass with minimal disturbance (e.g. residential lawns, golf courses, parks, commercial landscapes and greenbelts) sequester the greatest amounts of carbon, meaning that roots can grow deeper and soak up even more carbon.
• For the average managed lawn, turfgrass captures four times the carbon from the air than the carbon output of a typical mower.
• When comparing a well-managed lawn to a poorly managed lawn or unmanaged grasslands, the net carbon intake of a well-managed lawn is five to seven times higher than the carbon output of mowing.
• The largest amount of carbon intake occurs with the recycling of nitrogen contained in grass clippings, meaning clippings should be left on the ground to break down and recycle.
• To maximize carbon intake benefits, lawns and other turfgrass areas must be managed by cutting grass, leaving grass clippings, and responsible watering.
“It turns out that you can reduce your carbon footprint right in your own backyard,” said Kris Kiser, vice president, public affairs, OPEI. “Mowing grass and pruning shrubs and trees keeps plants in a growing state. This, in turn, ensures they are actively pulling carbon dioxide — a greenhouse gas — from the air.”
Added Sahu, “Your lawn, if managed properly, can be essentially a decent foot soldier in our quest to reduce our carbon footprint. The key is to actively manage your lawn to improve its carbon intake, and not letting it ‘go to seed’ and into a ‘dormant state.’”
The full report is available at www.opei.org/carbonreport.
OPE Editor Steve Noe