Fig. 2.
(a) X-ray diffraction patterns of the basally oriented clay fraction of the four soils after treatment: Mg saturated and air dried (Mg); Mg saturated and ethylene glycolated (Mg-EG), and K saturated and heated to 550°C (K-550); (b) random powder X-ray diffraction patterns of the four soils; and (c) random powder X-ray diffractions of the fresh biochar samples produced at 450°C (B450) and 550°C (B550). Identified peaks include hydroxy-interlayered vermiculite (HIV), illite (I), kaolinite (K), smectite (Sm), calcite (Ca), quartz (Q), feldspar (Fel), gibbsite (Gb), goethite (Goe), hematite (Hm), whewellite (W) and sylvite (Sy); Al represents Al peaks from the sample holder (and not the samples) that was used for the analysis.