Fig. 3From: Characterization of biochars produced from peanut hulls and pine wood with different pyrolysis conditionsCation exchange capacities (CEC) of chars and soil control (#15) that had been ground 4 min were determined for pH values from 8.5 to 5.0. Averages of duplicate assays for each sample are shown. Error bars are standard deviations for each sample’s averaged CEC assays (see Additional file 1: Table S1 in the Additional file)Back to article page