ASHS Press Releases

American Society for Horticultural Science

  • Increase font size
  • Default font size
  • Decrease font size
Home HortScience Reducing the Carbon Footprint of Urban Lawns
E-mail Print

COLUMBUS, OH—Atmospheric concentrations of carbon dioxide (CO2) have been on the rise since the industrial revolution. Looking for ways to mitigate or slow the release of CO2, one field of research is concentrating on the study of soil C (carbon) sequestration. Soil organic carbon (SOC) sequestration and the impact of carbon cycling in urban soils is a significant area of interest in horticultural researcher.

According to a new study, urban residents have great potential to affect C sequestration in their own backyards. "Seventy-five percent of the U.S. population lives in urban areas," noted Gina Zirkle, a scientist in Environmental Stewardship at Scotts Miracle-Gro Company. "Urban lawns are potential C sinks and their prevalence in urban landscapes suggests that lawns can store a significant amount of C," she noted. Zirkle and colleagues at the Carbon Management and Sequestration Center at The Ohio State University developed a simple model to compare the rate of SOC sequestration under a range of home lawn management practices. The model contrasted gross C sequestered versus hidden carbon costs associated with typical lawn maintenance practices. Results of the research appeared in HortScience.

The scientists studied three lawn management scenarios: minimal input, do-it-yourself, and best management practices. Minimal input (MI) lawns were defined as those that were mowed once a week without irrigation, fertilizer, or pesticide use. Do-it-yourself (DIY) practices featured intermittent watering, fertilizer use, and pesticide applications, while best management practices (BMPs) were classified by the use a lawn care service or application of fertilizer multiple times a year. "Lawn care services typically adopt university BMPs as a management program. This program is defined as mowing once per week, fertilizing four times a year with pest prevention, and irrigating regularly when rainfall is insufficient for healthy grass growth," Zirkle explained.

The data showed that an average size home lawn in the United States has the potential to sequester 20.3 to 163.4 kg C per lawn per year. The largest increase in C sequestration occurred when management practices increased from MI to DIY. Employing best management practices increased the rate of SOC sequestration even more.

SOC sequestration was not the only factor considered. The scientists also evaluated hidden carbon costs (HCC), which they explained can offset the benefits of C sequestration, especially at the higher levels of lawn management. Mowing, irrigating, fertilizing, and using pesticides are all products of energy-based inputs; HCCs are defined as the amount of energy expended by these practices—from manufacturing to the amount of energy used in actual lawn care. "Lawns in the arid southwest under a BMP lawn program have more HCC and a lower net rate of SOC sequestration. In contrast, a lawn in the northeast under a DIY program requires less HCC to maintain a healthy lawn and has a higher rate of SOC sequestration," Zirkle said.

The research determined that residential landscapes are a positive net sink for atmospheric CO2 under all the evaluated levels of landscapes. "Even though there are hidden carbon costs associated with lawn management practices, the potential for soils to sequester C may offset these costs," the team concluded. "Residential landscapes have a significant influence on the C cycle."

###

The complete study and abstract are available on the ASHS HortScience electronic journal web site: http://hortsci.ashspublications.org/cgi/content/abstract/46/5/808

Founded in 1903, the American Society for Horticultural Science (ASHS) is the largest organization dedicated to advancing all facets of horticultural research, education, and application. More information at ashs.org


 

Original Article:

Modeling Carbon Sequestration in Home Lawns
Gina Zirkle, Rattan Lal, and Bruce Augustin
HortScience 46:808–814. [Abstract][Full Text][PDF]

Corresponding author. E-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it