Fig. 3
From: Effect of biochar addition on legacy phosphorus availability in long-term cultivated arid soil
Soil P fraction percentage of soil total P 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) in comparison to untreated soil (CONT)