Fig. 6
From: Effect of biochar addition on legacy phosphorus availability in long-term cultivated arid soil
Phosphorus availability response (PAR) rate in soil treated with 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. Treatments sharing the same letter are considered not significantly different based on Student–Newman–Keuls (SNK) test–LSD test at (P < 0.05)