Biochar may not be the miracle soil additive that many farmers and researchers hoped it to be, according to a new University of Illinois study. Biochar may boost the agricultural yield of some soils – especially poor quality ones – but there is no consensus on its effectiveness. Researchers tested different soils’ responses to multiple biochar types and were unable to verify their ability to increase plant growth. However, the study did show biochar’s ability to affect soil greenhouse gas emissions.
The new findings are published in the journal Chemosphere.
Biochar additives – particles of organic material burned in a controlled oxygen-free process – provide soil with a form of carbon that is more resistant to microbial action than traditional, uncharred biomass additives. In theory, this property should allow soil to hold onto carbon for long-term storage, the researchers said, because it does not degrade as rapidly as other forms of carbon.
“There are conflicting reports on the effectiveness of biochar for use to increase crop production as well as its potential as a carbon-storage reservoir,” said Nancy Holm, an Illinois Sustainable Technology Center researcher and study co-author. “We came into this study suspecting that variations in types of biochar feedstock, preparation methods and soil composition were the cause of the conflicting results.”
Read more at University of Illinois at Urbana-Champaign, News Bureau
Image: Illinois Sustainable Technology Center researchers Elizabeth Maschewski, left, and Nancy Holm and collaborators developed a systematic study to test the effectiveness of the soil additive biochar and found that it may not be as effective as previously thought. (Credit: Photo courtesy Nancy Holm)