University of Tübingen microbiologists show soil microbe communities can be influenced to decrease nitrous oxide emissions.
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| Biochar |
Introducing biochar into agricultural soils changes the composition
and activity of microorganisms in a way that emissions of nitrous oxide
-- also known as laughing gas (N2O) -- are significantly
reduced, according to researchers Johannes Harter and Hans-Martin
Krause. Their study was supervised by environmental microbiologist Dr.
Sebastian Behrens and geomicrobiologist Professor Andreas Kappler of the
Center for Applied Geosciences at the University of Tübingen in
cooperation with researchers from the University of Hohenheim. The
results are important not only for a sustainable, more effective use of
nitrogen fertilizers; they also present a new possibility for reducing
greenhouse gas emissions worldwide.
Biochar is produced by high-temperature thermochemical decomposition
of organic material, a process known as pyrolysis. Unlike charcoal,
which is primarily used to produce heat, biochar is used as a soil
supplement in agriculture. Nitrous oxide is produced by
nitrogen-transforming microorganisms in the soil, and these emissions
increase with the use of nitrogen fertilizers. Biochar's surface
properties prevent nutrients from being washed out of poor soils. It
also positively influences the abundance, composition, and activity of
microorganisms in the soil, which form complex biological communities
involving plants and animals. "Soil biochar amendment helps to raise
water storage capacity and decrease soil nutrient leaching, which in
turn increases soil fertility and can help to reduce greenhouse gas
emissions because it stores carbon in the soil," says Sebastian Behrens.
Indigenous peoples in tropical zones of South America and Africa were
aware of biochar's positive effect on soil and plant growth thousands
of years ago. The current study underlines the importance of biochar
research -- because biochar not only has the potential to open
profitable new markets for agriculture and industry, it also provides
data important to the protection of soils and the climate.
The results are also important in the light of the recently-released
5th Assessment Report, in which the United Nations Intergovernmental
Panel on Climate Change (IPCC) revealed that concentrations of the
greenhouse gases CO2, methane and nitrous oxide in the
atmosphere have risen by 40%, 150% and 20%, respectively since 1750
because of human activity. The main source of nitrous oxide is
agriculture (84%). It is therefore of great economic and environmental
importance to find strategies to reduce nitrous oxide emission while
making nitrogen fertilizer use sustainable -- and maintaining crop
yields.
Source : sciencedaily.com
