From Soil Science Society of America
Special to Road Trips for Gardeners

Using best practices, in the long-term, can reduce greenhouse gases and help the environment. A post in The Soil Science Society of America (SSSA) “Soils Matter” blog explains how gardens and lawns can be used to store more carbon in soil.

Plants capture carbon dioxide (CO2) from the atmosphere during photosynthesis. They convert the CO2 to simple sugars that plants use for energy and growth, or structural compounds such as fibers and cellulose. This is the first step of what scientists call carbon sequestration – or carbon storage.

When plant roots die, or when plant parts are incorporated into the soil, soil-dwelling insects, worms and microorganisms break down the sugars and other compounds to “eat”. Some of the carbon is released back to the atmosphere as CO2 by the microorganisms. Some remains in the soil. Some of the plant matter is harder to break down, and becomes part of the soil’s organic matter. This is a natural process of carbon sequestration. Plants capture CO2, a greenhouse gas, and place it in the soil in more stable forms.

Of course, the process works in reverse, too. Those sugar-eating microorganisms do release some CO2 into the atmosphere – just like humans do when we breathe out!

If you think about the two CO2 cycles just described, our goals are to improve plant growth (use of CO2) and reduce the breakdown of plant residues (release of CO2). Doing these captures and retains more carbon in the soil.

“Our goals are to improve plant growth (use of carbon dioxide) and reduce the breakdown of plant residues (release of carbon dioxide),” says Jim Friedericks, Outreach and Education, AgSource Laboratories.

Friedericks offers tips to increase carbon storage in soil:

*Allow grass in your yard to grow a bit longer before mowing. This encourages more root growth below ground.
*Longer grass leaves also means more grassy leaf area–and that means more carbon dioxide is captured from the air.
*Plant perennials. Plants that live longer accumulate biomass -– which is made of carbon (the woody stems or trunks, and their extensive roots).
*Cover your soil with plants or mulch. Bare soil is prone to erosion, and does not foster the best plant growth. Mulch conserves moisture and supplies nutrients to the soil.
*Minimize or eliminate tilling to keep carbon dioxide in the soil and slow the decomposition of organic matter.

Friedericks writes, “Small steps that encourage plants to grow and slowly add the plant residue back to the soil will convert carbon dioxide into more stable forms of carbon. There are things that you can do that make a difference!”

To read the entire blog post, go online

(Photo and image courtesy of Soil Science Society of America)