Location: Soil, Water & Air Resources ResearchTitle: Abundant and stable char residues in soils: Implications for soil fertility and carbon sequestration Author
|Olk, Daniel - Dan|
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 10/9/2012
Publication Date: 2/4/2013
Citation: Mao, J., Johnson, R.L., Lehmann, J., Olk, D.C., Neves, E.G., Thompson, M.L., Schmidt-Rohr, K. 2013. Abundant and stable char residues in soils: Implications for soil fertility and carbon sequestration. In: Xu, J., Wu, J., He, Z., editors. Functions of Natural Organic Matter in a Changing Environment. Dordrecht, The Netherlands: Springer. p. 479-484. Interpretive Summary:
Technical Abstract: Large-scale soil application of biochar might enhance soil fertility and increase crop production, while also sequestering atmospheric carbon. Reaching these outcomes requires an undertanding of the chemical structure of biochar. Using advanced solid-state 13C nuclear magnetic resonance spectroscopy, we show that the char residues in Terra Preta soils of Brazil are composed of aromatic rings having ~5 fused carbons that are substituted by COO- groups. These negatively charged peripheral groups will likely increase the soils' cation exchange capacity. We also show that in highly productive grassland-derived U.S. soils char generated by pre-settlement fires is structurally comparable to that of the Terra Preta soils. These oxidized char residues represent a particularly stable, abundant, and fertility-enhancing form of soil organic matter.