taken from http://www.corriere.it/scienze_e_tecnologie/09_marzo_10_
will be the revival, in modern terms, of an ancient pre-Columbian agriculture techniques to save the planet by the greenhouse effect? The hypothesis is suggestive but not farfetched: they are working in various scientific research centers around the world, including the Institute of Biometeorology CNR (Ibimet) in Florence, where a team of researchers coordinated by Dr. Franco Miglietta scored already very encouraging results. Read the article
The biochar is a charcoal that is obtained by pyrolysis of different types of biomass. Of particular interest is its production from agricultural waste: trimming, corn or wheat stubble, rice husks, almond husk, dry leaves, etc.. The biomass pyrolysis can be obtained from a gas (syngas) with a calorific value of LPG that can be used in manufacturing processes that require heat (eg drying), heat rooms or be transformed into electricity.
The product of pyrolysis is biochar (90% carbon) which, if applied to soils, is a potent fertilizer. Its high porosity makes it possible the storage of water and nutrients that are longer available for plants, also improves soil structure and its mechanical properties (Chan et al., 2007). Several studies have demonstrated the positive impact that the application of biochar has on agricultural yields by reducing the demand for water and nutrients (Nishio, 1996; Hoshi, 2001, Lehmann et al., 2003, Yamato et al., 2006, Chan et al., 2007; Rondon et al., 2007).
The aromatic structure of biochar makes this product not to be degraded by soil microorganisms, and then to store carbon rather than return it to the atmosphere as CO2 as in the case of compost or burning of pruning (Kuhlbusch et al., 1996, Lehmann et al., 2002, Harris and Hill, 2007). Moreover, according to Yanai et al. (2007), the use of biochar on agricultural land can reduce emissions of N2O from the soil, a greenhouse gas with 296 times the Global Warming Potential of CO2 (IPCC, 2001).
As a result, the biochar is the only technique for mitigation of climate change that is not just carbon neutral but actually carbon negative, or sequester more carbon than it emits to produce energy. It is estimated that a 250 ha farm using bio-char added nitrogen is able to seize 1,900 tons of coal per year. Further research is needed in the field, but the results obtained so far are positive enough to make believe this is the most promising strategy for mitigating climate change.
know more about visiting the following link:
http://ec.europa.eu/environment/integration / research / newsalert / pdf /
