I referenced an article published in 2005 in the previous blog post in regards to home lawns and the topic still holds true today and maybe even more so now. There are good reasons to think about the impact of lawns on the water and carbon cycle and how homeowners can implement practices that will help their landscape be more efficient at sequestering carbon and helping the environment.
According to the 2010 Unites States Census Bureau, 75% of the U.S. population lives in urban areas with an estimated 40-50 million acres of urban grasslands. Homeowners could, therefore, potentially affect carbon sequestration with their own home landscape and garden.
What is carbon sequestration? There are three types of carbon sequestration, Biological, Geological and Technological. For the purposes of this blog we will refer to Biological carbon sequestration, which is the storage of carbon dioxide from the atmosphere in plants, soils and oceans.
Sound familiar? Keep reading.
A typical suburban home has landscape beds, shrubs, trees and a grass lawn. The grass lawn captures 81-90% of the carbon sequestered by the landscape, according to the Lawn Institute. Landscape management practices can also affect how much carbon is sequestered. Lal and Augustin, 2011 reported the differences in carbon sequestration in home lawns based upon lawn maintenance practices ranging from low to high management.
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Low management: minimal input included mowing only and had a net soil organic carbon sequestration rate of 25.4 to 114.2 g C/m2/year.
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Medium management: The do-it yourself (DIY) management by homeowners was 80.6 to 183.0 g C/m2/year.
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High management: based upon university and industry-standard best management recommendations had a net soil organic carbon sequestration rate of 51.7 to 204.3 g C/m2/year.
How do plants capture or sequester carbon - well, this type of biological sequestration is called ……photosynthesis.
Photosynthesis is the process in which green plants use sunlight to make their own food.
Plants capture light energy from the sun, carbon, as carbon dioxide from the atmosphere and water from the root system and the air.
The green part of the plant will use the light energy from the sun to change the water and carbon dioxide into a sugar called glucose.
Glucose is used by the plant for food and the oxygen is released into the air. The plant also sends 40–50% of this food down to the roots. The root system fixes about 1.5-10 times the amount of carbon as the above ground part of the plant.
Lawns, beautifully landscaped yards and gardens sequester carbon through photosynthesis. How much have we considered the role of soil in carbon sequestration? I have heard so many people say soil is just dirt - dirt is something you sweep up off your kitchen floor. Soil is so much more than that.