Biochar affects carbon composition and stability in soil: a combined spectroscopy-microscopy study.
The use of biochar can contribute to carbon (C) storage in soil. Upon addition of biochar, there is a spatial reorganization of C within soil particles, but the mechanisms remain unclear. Here, we used Fourier transformed infrared-microscopy and confocal laser scanning microscopy to examine this reorganization. A silty-loam soil was amended with three different organic residues and with the biochar produced from these residues and incubated for 237 d. Soil respiration was lower in biochar-amended soils than in residue-amended soils. Fluorescence analysis of the dissolved organic matter revealed that biochar application increased a humic-like fluorescent component, likely associated with biochar-C in solution. The combined spectroscopy-microscopy approach revealed the accumulation of aromatic-C in discrete spots in the solid-phase of microaggregates and its co-localization with clay minerals for soil amended with raw residue or biochar.The co-localization of aromatic-C:polysaccharides-C was consistently reduced upon biochar application. We conclude that reduced C metabolism is an important mechanism for C stabilization in biochar-amended soils.
Department of Earth and Environmental Science, KU Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium.|The University of Queensland, School of Agriculture and Food Sciences, St. Lucia, Queensland, 4072, Australia.
Maria C
MC
Hernandez-Soriano
Department of Earth and Environmental Science, KU Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium.
Bart
B
Kerré
The University of Queensland, School of Agriculture and Food Sciences, St. Lucia, Queensland, 4072, Australia.
Peter M
PM
Kopittke
Department of Earth and Environmental Science, KU Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium.
Benjamin
B
Horemans
Department of Earth and Environmental Science, KU Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium.
Erik
E
Smolders
D002244:Carbon / Q000032:analysis*; D002606:Charcoal / Q000378:metabolism*; D018613:Microscopy, Confocal; D009930:Organic Chemicals / Q000378:metabolism; D012987:Soil / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
D009930:Organic Chemicals; D012987:Soil; C540010:biochar; D002606:Charcoal; D002244:Carbon