April 25, 2011, Madison, WI – Nitrous oxide is a potent greenhouse gas
and a precursor to compounds that contribute to the destruction of the
ozone.
April 25, 2011, Madison, WI – Nitrous oxide is a potent greenhouse gas
and a precursor to compounds that contribute to the destruction of the
ozone. Intensively managed, grazed pastures are responsible for an
increase in nitrous oxide emissions from grazing animals’ excrement.
Biochar is potentially a mitigation option for reducing the world’s
elevated carbon dioxide emissions, since the embodied carbon can be
sequestered in the soil. Biochar also has the potential to beneficially
alter soil nitrogen transformations.
Laboratory tests have indicated that adding biochar to the
soil could be used to suppress nitrous oxide derived from livestock.
Biochar has been used for soil carbon sequestration in the same manner.
In a study funded by the Foundation for Research Science and
Technology, scientists at Lincoln University in New Zealand, conducted
an experiment over an 86-day spring/summer period to determined the
effect of incorporating biochar into the soil on nitrous oxide
emissions from the urine patches produced by cattle. Biochar was added
to the soil during pasture renovation and gas samples were taken on 33
different occasions.
Addition of biochar to the soil allowed for a 70 percent reduction in
nitrous oxide fluxes over the course of the study. Nitrogen
contribution from livestock urine to the emitted nitrous oxide
decreased as well. The incorporation of biochar into the soil had no
detrimental effects on dry matter yield or total nitrogen content in
the pasture.
Arezoo Taghizadeh-Toosi who conducted the study, says that under the
highest rate of biochar, ammonia formation and its subsequent
adsorption onto or into the biochar, reduced the inorganic-nitrogen
pool available for nitrifiers and thus nitrate concentrations were
reduced. Such effects would have diminished the substrate available for
microbial nitrous oxide production.”
Research work is ongoing and still required to determine
seasonal effects. The study was published in the March/April 2011 issue
of the Journal of Environmental Quality.
The full article is available for no charge for 30 days
following the date of this summary. View the abstract at
https://www.agronomy.org/publications/jeq/abstracts/40/2/468.
