ISTC scientists have studied biochar since 2008, focusing on its use as a soil amendment, energy source, replacement carbon source, and carbon sequestration method.
What is Biochar?
A charcoal-like product produced by the pyrolysis of biomass, biochar is composed largely of carbon. Pyrolysis is a thermochemical conversion process in which biomass is heated at high temperature (usually 450°-750°C) in the absence of oxygen to produce energy products, including biochar (along with bio-oil and syngas). Biochar retains the feedstock’s original structure but has increased porosity.
Uses
Biochar use dates back centuries, when people used it to enrich Amazonian soils. More on the history of biochar and charcoal use in soils is available in the webinar Biochar: The science behind the hype, presented by USDA-ARS Soil Scientist Kurt Spokas.
However, biochar has recently piqued scientists’ interest worldwide because it can improve soil fertility and sequester carbon, while also providing a productive way to use waste biomass.
While using biochar in soil may not be new, little is understood about how it behaves in the environment, and more information is needed on its wide range of potential uses. In recent years, science has explored a range of biochar applications (not only in soils, but also in water treatment, energy storage, heavy metal mitigation, animal bedding, and more), and many field trials are being conducted worldwide.
Agriculture
Produced from a variety of biomass and agricultural wastes, biochar has enormous potential to help the environment and strengthen the agricultural economy. When used as a soil amendment, biochar has been shown in certain soils to boost fertility and improve soil quality by trapping moisture, attracting more beneficial fungi and microbes, improving cation exchange capacity, and helping the soil hold nutrients while absorbing heavy metals and pesticides. Therefore, biochar can potentially increase crop yields, reduce the amount of chemical fertilizers needed, and minimize the adverse environmental effects of agrochemicals. Because of these properties, biochar has been proposed for other agricultural applications, such as water filtration and as an additive in livestock feed to reduce methane emissions.
However, these benefits are not seen in every agricultural application. Some soil studies have shown that biochar has no effect, or even a negative effect, on productivity because of contaminants produced during the production process.
ISTC scientists have conducted several studies using biochars in agriculture to determine their viability as an agricultural product and tool.