What is Biochar?
What exactly is BioChar?
Biochar is pyrolized biomass, or biomass that has been burned in the absence of oxygen. This process creates a highly porous structure that provides the optimum host for soil microbes. Biochar also holds 50% of the biomass’ carbon and when applied to soil, sequesters that carbon for centuries, reducing the overall amount of atmospheric CO2 by removing it from the active cycle. Biochar also enhances plant growth which absorbs more CO2 from the atmosphere. Overall, these benefits make the biochar process carbon negative.
How does it work?
Biochar stimulates the activity of a variety of agriculturally important soil microorganisms, and can greatly affect the microbiological properties of soils. The pores in biochar provide a suitable habitat for many microorganisms by protecting them from predation and drying while providing many of their diverse carbon (C) energy and mineral nutrient needs. Since soil organisms provide a myriad of ecosystem services, adding biochar to soil may affect soil ecology and is critical for assuring that soil quality and the integrity of the soil rhizophere are maintained.
How is it used?
The natural process of biochar is found in soils around the world as a result of vegetation fires and historic soil management practices. Intensive study of biochar-rich dark earths in the Amazon (terra preta), has led to a wider appreciation of biochar’s unique properties as a soil enhancer. Biochar also improves water quality and quantity by increasing soil retention of nutrients for plant and crop utilization. More nutrients stay in the soil instead of leaching into groundwater and causing pollution.
How can biochar help farmers?
Biochar has consistently showed an increase in yields for most agriculture crops and is a preferred amendment in organic farming. There is also evidence from thousands of years of traditional use of charcoal in soils. The most well-know example is the fertile Terra Preta soils in Brazil, but Japan also has a long tradition of using charcoal in soil, a tradition that is being revived and has been exported over the past 20 years to countries such as Costa Rica. The Brazilian and Japanese traditions together provide long-term evidence of positive biochar impact on soils.
Can biochar sequester carbon?
Recent studies have indicated that incorporating biochar into soil reduces nitrous oxide (N2O) emissions and increases methane (CH4) uptake from soil. Methane is over 20 times more effective in trapping heat in the atmosphere than CO2, while nitrous oxide has a global warming potential that is 310 times greater than CO2. Although the mechanisms for these reductions are not fully understood, it is likely that a combination of biotic and abiotic factors are involved, and these factors will vary according to soil type, land use, climate and the characteristics of the biochar. An improved understanding of the role of biochar in reducing non-CO2 greenhouse gas (GHG) emissions will promote its incorporation into climate change mitigation strategies, and ultimately, its commercial availability and application.
Regional Biochar groups help support local biochar research and projects applicable to that geographical area. These regional groups often hold conferences and meetings, provide updates on regional biochar projects to their members, undertake projects such as field tests and biochar production, advocate for policy on the local and regional levels, write and publish reports, and provide a network of people all working in a similar geographic area.