Carbon, hydrogen, and nitrogen contents of the biochars were
determined using a CHN Elemental Analyzer (Carlo-Erba NA-
1500) via high-temperature catalyzed combustion followed by
infrared detection of resulting CO2, H2 and NO2 gases. Major inorganic
elemental constituents of the biochars were determined
using the EPA 200.7 method of acid digestion followed by analysis
by inductively coupled plasma with atomic emission spectroscopy
(ICP–AES).