Location: Commodity Utilization ResearchTitle: Field-scale fluorescence fingerprinting of biochar-borne dissolved organic carbon
Submitted to: Journal of Environmental Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/8/2015
Publication Date: 1/1/2016
Citation: Uchimiya, M., Liu, Z., Sistani, K. 2016. Field-scale fluorescence fingerprinting of biochar-borne dissolved organic carbon. Journal of Environmental Management. 169:184-190.
Interpretive Summary: Reliable and quantitative method is on demand to validate the amount of recalcitrant carbon stock in agricultural soils. This work presents a new, cheap, easy, and rapid method to measure how much carbon is sequestered in agricultural soil. Solvent extraction was utilized to specifically target stable carbon stored in soil. The method will aid producers verify the carbon budget in their farm soils.
Technical Abstract: Biochar continues to receive worldwide enthusiasm as means of augmenting recalcitrant organic carbon in agricultural soils. Realistic biochar amendment rate (typically less than 1 wt%) in the field scale, and loss by sizing, rain, and other transport events demand reliable methods to quantify the remaining portions of amended biochar. This study employed fluorescence excitation-emission (EEM) spectrophotometry and parallel factor analysis (PARAFAC) to specifically target pyrogenic dissolved organic carbon (DOC) released by amended biochar during the course of a field trial at Bowling Green, KY experimental site. Toluene/methanol (1:6 v/v) extracts of surface (0-15cm) soils amended with 21.28 t ha-1 fast pyrolysis biochar afforded PARAFAC fingerprints representing different degrees of aromaticity. Compared to the control without treatments, biochar treatment (with and without poultry manure or chemical fertilizer) increased the relative contribution of PARAFAC fingerprint attributable to labile polyaromatic DOC structures. Poultry manure or chemical fertilizer alone (without biochar) did not influence of amounts of polyaromatic DOC structures. Existence of biochar could be further validated by the changes in %DOC (relative to the total carbon), fixed C content, and UV absorbance (360 nm), whereas FTIR, %O, and sorption of model agrochemical (deisopropylatrazine) did not reflect the presence of biochar in soil samples.