%0 Journal Article
%T Characterization and Mineralization Rates of Low Temperature Peanut Hull and Pine Chip Biochars
%A Keith Harris
%A Julia Gaskin
%A Miguel Cabrera
%A William Miller
%A K.C. Das
%J Agronomy
%D 2013
%I MDPI AG
%R 10.3390/agronomy3020294
%X Biochar can potentially increase soil fertility and sequester carbon by incorporating nutrients and stable black carbon into the soil; however its effect on soil nitrogen (N) and carbon (C) processes is not well understood. A defined methodology to characterize biochar is necessary to predict how specific biochars will affect C and N mineralization. We amended a Tifton soil (Fine-loamy, siliceous, thermic Plinthic Kandiudults) with peanut hull ( Arachis hypogaea; PH; 2.1% N) and pine chip ( Pinus taeda; PC: 0.4% N) biochar at application rates of 1% and 2% (w/w) and performed a 136-day mineralization study. A companion 24-day mineralization study amended Tifton soil with PH and PC biochar at 2% and their respective feedstocks at equal C rates. Soil C mineralization rates were monitored periodically throughout each study and total N mineralization rates were also measured. In addition, we characterized each biochar using thermogravimetric analysis with mass spectrometer (TGA-MS), proximate analysis, Fourier transform infrared spectroscopy (FTIR), and total mineral analysis to identify biochar characteristics that might correlate with mineralization properties. Limited C (<2%) mineralized from both biochars, but mineralization rates of soil amended with PH biochar were higher than PC biochar. Carbon mineralization correlated well with estimated aliphatic content determined by TGA-MS but not with volatile content indicated by proximate analysis. Nitrogen was not mineralized from either biochar, indicating that plant-based biochar should not be considered a source of N for plant growth. The N in biochar may be contained in the stable aromatic structure of the biochar, as indicated by TGA-MS, and not available to soil microbes.
%K biochar
%K soil
%K mineralization
%K characterization
%K carbon
%K nitrogen
%U http://www.mdpi.com/2073-4395/3/2/294