Biochar: Growing Community Solutions
Biochar is a substance that is created through pyrolysis, a process by which organic material (such as brush, grass clippings, crop waste, manure) is heated in an oxygen free environment. This can be accomplished in small household stoves or industrial furnaces, but unlike oxygen-fueled fire, carbon dioxide is not emitted. Instead, the carbon is bound or sequestered in black chunks similar to charcoal.
While scientists have known since 2003 that burying biochar in agricultural fields helps hold moisture and nutrients and increases crop yield, researchers in New Zealand have recently discovered that it can play a major role in reducing emissions of both carbon dioxide and nitrous oxide, two major greenhouse gases.
Biochar reduces carbon dioxide emissions because of its relative stability. Once buried in the ground, it can last for hundreds if not thousands of years. This has the effect of storing carbon and keeping it out of the atmosphere. At the same time, adding biochar to the soils of livestock pastures also decreases nitrous oxide emissions. According to the latest laboratory studies performed by Lincoln University in New Zealand, incorporating biochar into pasture soils decreased nitrogen fluxes by approximately 70% over the course of the study. Biochar additions also led to a decrease in the amount of nitrous oxide emitted from livestock urine patches.
The Lincoln University study concluded that when biochar is added to pasture soils, ammonia adsorbs to and is held by it. Consequently, this reduces the amount of inorganic nitrogen available in the soil for nitrifying bacteria to convert into nitrites and nitrates. By reducing soil nitrates, there is less material available for microbial nitrous oxide production.
These developments can be significant for local communities that want to do something about climate change. Biochar has great potential as an effective tool in the arsenal against climate change because of its incredible scalability, yielding localized and regional economic and ecological benefits. Individual consumers or farmers can produce small quantities in household stoves for private use, and manufacturers can produce enormous amounts in industrial furnaces for widespread use in commerce. By incorporating it into garden, pasture, and cropland soils, everyday people can help prevent organic carbon and nitrous oxide from entering the atmosphere.
For more information, see
Can biochar suppress greenhouse gases?
Biochar emerges as major tool for curbing carbon
How biochar production could help climate change fight
Make Biochar – this Ancient Technique Will Improve Your Soil
