CINCINNATI, Ohio -- Carbon sequestration -- storing soil carbon using conservation tillage practices -- is a slow process that can take years to show results. But there is a way to measure soil carbon value more quickly.
Ohio State University agricultural engineers and soil fertility specialists have found that breaking down total soil carbon into its various components and analyzing each one provides a more immediate picture of carbon sequestration and its benefits. Randall Reeder, an Ohio State University Extension agricultural engineer and conservation tillage specialist, said that the information could help growers see the value of conservation tillage practices when it comes to carbon sequestration efforts.
"If you are just measuring total soil carbon, you don't see much difference between no-till and intensive tillage practices when it comes to carbon storage. It may take 10 or 20 years to show a significant change," said Reeder, who holds an Ohio Agricultural Research and Development Center appointment. "But by measuring the components of soil carbon, you can see that good things are happening in no-till fields. The results verify that no-till has value without having to wait so many years to prove it."
Reeder and his colleagues (OSU Extension educator Alan Sundermeier and Rafiq Islam, an OSU South Centers at Piketon soil fertility specialist) compared carbon sequestration between no-till and tilled fields after five years at OARDC's Northwest Agricultural Research Station near Hoytville, Ohio. They found no difference between tilled and no-till fields when total soil carbon was measured. However, when the carbon was broken down into fractions (microbial carbon, active carbon, particulate organic matter and extractable carbon) and each one was measured, researchers found signficant results with carbon storage in no-till fields.
"Everyone hears about total carbon, but what really counts is the components of carbon and how those change based on specific production practices," said Reeder. "We couldn't see the differences when we measured total carbon, but when we tested the soil for components of carbon we found that they can be early indicators of carbon sequestration."
Reeder and his colleagues will present their research results at the 16th annual National No-Till Conference on Jan. 9 from 3:20 p.m. to 4:10 p.m. The conference will take place Jan. 9-12 at the Netherland Hilton Hotel in Cincinnati, Ohio. Complete agenda and registration information can be found at http://www.notillfarmer.com, by calling (800) 645-8455 or e-mailing firstname.lastname@example.org.
Islam, who analyzed the soil samples at his lab in Piketon, said that measuring total carbon alone doesn't provide the full picture because much of the carbon is locked in the soil and unavailable for plants. Certain fractions of carbon, however, such as microbial carbon, are available for plants to use. The most significant measure of carbon sequestration came from microbial carbon.
"For every 100 pounds of total carbon in soil, about 1 pound is microbial biomass carbon, 10 to 30 pounds are active carbon and 40 to 50 pounds are particulate organic carbon," said Islam, who holds an OSU Extension appointment. "Increasing microbial carbon, even doubling it, is good for plant growth even though it may increase total carbon very little."
Reeder and his colleagues will also present findings on the impacts of compaction on carbon sequestration. By analyzing the components of carbon, the researchers found that compaction reduces carbon sequestration.
"Compaction generally reduces yields, in part because of less root growth. Much of the carbon deep in the soil comes from decaying roots," said Reeder, "so it is logical that compacted soils accumulate less carbon."
Reeder said that the results of the compaction study add value to practicing controlled traffic -- a method to manage soil compaction, whereby all farm equipment is the same width and traffic is confined to specific paths year after year. With this system, between 50 and 80 percent of the soil is untouched by heavy traffic, which means carbon can be sequestered more quickly.
Other Ohio presenters during the National No-Till Conference include Washington Court House no-till farmers Tony and Doug Anderson, who will present information on strip tillage; Mount Vernon crop consultant Mike Dailey, who will offer tips to build extra profits in no-till soybeans; and Ed Winkle of Hymark Consulting in Martinsville, who will offer tools to make no-till more profitable and sustainable.
The National No-till Conference will feature presentations by leading researchers, agri-business firms, and farmers who will share hundreds of field-tested ideas to increase yields and profits by farming with no-till farming methods. The conference will also feature dozens of exhibits from seed, chemical, fertilizer, machinery and equipment, computer hardware and software, and other agri-business companies. The National No-till Conference, widely regarded as the premier conservation tillage conference, draws approximately 700 no-till farmers, agriculture officials and university researchers from around the country.