APPLICATIONS FOR CARBON SEQUESTRATION
TOPICS:Biochar application research | Biochar land application study
TERRA PRETA: A POSSIBLE MODEL FOR CARBON SEQUESTRATION
Slash and char was described as an alternative practice to slash and burn and charcoal is currently used by some Amazonian settlers to improve soil fertility. If biomass is burned, only a very small percentage of the carbon is converted into charcoal, but when pyrolyzed, charcoal production can capture 50% of the carbon stored in biomass. Charcoal when used as a soil amendment (biochar) shows very high recalcitrance against biological or chemical decay and stores carbon over centuries or millennia.
Conservation and restoration of soil organic matter (SOM) is of crucial importance to maintain soil fertility. Biochar management holds out the prospect to rapidly increase SOM and maintain it in soils for long periods of time.
Most potting soils, herbicides in carbon-based formulations, and culture media formulations contain charcoal or activated carbons, although the scientific rationale for these applications is not always known. Recent studies showed that biochar amendments are indeed capable of increasing soil fertility. Biochar can improve soil chemical, biological, and physical properties, but the mechanisms of fertility enhancement are not completely discerned. The effects on soil biology seem to be essential as charcoal has the potential to alter the microbial biomass and composition.
On a global scale, the total carbon release flux due to fire is almost as large as that from fossil fuel consumption. This emphasizes the potential for C management by only using biomass that would otherwise be ablaze each year. The global potential of biochar reaches far beyond slash and char. Inspired by the recreation of Terra Preta, most biochar research was restricted to the humid tropics. More information is needed on the agronomic potential of charcoal, the potential to use alternative biomass sources (crop residues) and production of byproducts to evaluate the opportunities for adopting a biochar system on a global scale. Biochar as soil amendment needs to be studied in different climate and soil types. Today, crop residue biomass represents a considerable problem as well as new challenges and opportunities.
A system converting biomass into energy (e.g. hydrogen-rich gas) and producing charcoal as a byproduct might offer an opportunity to address these problems. Charcoal can be produced by incomplete combustion from any biomass, and it is a byproduct of the pyrolysis technology used for biofuel and ammonia production. Energy from crop residues could lower fossil energy consumption and CO2 emissions, and become a completely new income source for farmers and rural regions. The biochar byproduct of this process could serve to recycle nutrients, improve soils and sequester carbon.
UGA's Biochar Research and Outreach Group focuses on the following broad areas of work: