Fig. 1
From: Effect of biochar addition on legacy phosphorus availability in long-term cultivated arid soil
Effects of biochars derived from sewage sludge (SSB), olive pomace (OPB), chicken manure (CMB), and date palm residues (DRB) produced at 300 (3), 500 (5), or 700 (7) °C in comparison to a control treatment (CONT) on soil labile inorganic (Pi) and organic P (Po) fractions: A Resin-Pi, B NaHCO3-Pi, and -– NaHCO3-Po. For a P fraction, treatments sharing the same letter are considered not significantly different based on Student–Newman–Keuls (SNK) test–LSD test at P < 0.05. Errors bars represent standard error of treatment mean (n = 3)