April 13, 2005,
ARS News Service: No-till soil management can
play an important role in keeping carbon in the soil,
rather than allowing it to escape into the atmosphere
as carbon dioxide, according to a cooperative study
by Agricultural Research Service (ARS) and Brazilian
scientists at Beltsville, Md.
Capturing carbon and other substances in the soil keeps
them from contributing to "global warming"
as greenhouse gases.
Brazilian scientist Helvecio De-Polli worked on the
study from 2002-2004 with ARS soil scientist Gregory
McCarty and others at ARS' Environmental Quality Laboratory
(EQL) in Beltsville. De-Polli works for the Brazilian
Ministry of Agriculture, Livestock and Food Supply's
Empresa Brasileira de Pesquisa Agropecuaria (Embrapa).
The soil carbon study was done at a field site where
researchers had conducted a 10-year tillage experiment
comparing no-till farming with cultivation by plowing.
Soil microbial biomass and carbon stocks stored in the
soil were measured at the end of the 10-year period.
Also, emissions of methane, carbon dioxide and nitrous
oxide from the soil were monitored for an entire year.
These three are the most important "greenhouse
gases" exchanged between agricultural systems and
Microbes are responsible for processes in the soil
that produce these gases. A complete understanding of
greenhouse gas emissions is important to development
of methods to capture soil carbon, according to De-Polli.
His work shows that no-till farming can play a positive
role in mitigating greenhouse gases by capturing carbon
that's stored in the soil in plant tissues which remain
in the field after the crop is harvested.
Read more about this research in the April issue of
Agricultural Research magazine, available online at:
ARS is the U.S. Department of Agriculture's chief
scientific research agency.