Chemical and physical properties of biochar.
Link to this table

Property Range found in literature1 Median value from literature
Total phosphorus (% dry wt) 0.036 - 0.41 0.3
Total nitrogen (% dry wt) 0.39 - 0.5 0.5
Total potassium (% dry wt) 0.4 - 2.39 0.819
Total carbon (%) 42 - 49 47.1
Total hydrogen (%) 4.4
pH 4.9 - 6.9 5.9
Cation exchange capacity (cmol/kg) 31.7 - 130 50
Surface area (m2/g
Electrical conductivity (ds/m) 39 - 2900 582
Total calciium (%) 0.18
Total magnesium (%) 0.11
Total copper (mg/kg) 10.3
Total zinc (mg/kg) 4
Total manganese (mg/kg) 92
Water holding capacity 52-69
Bulk density (g/cm3) 0.025 - 0.132 0.06
Water holding capacity (% by wt) 137 - 1100 566
Total pore space (%) 85.5 - 98.3 95.2

Primary references for this data:

  • Cresswell
  • Abad et al., 2002
  • Abad et al., 2005
  • Asiah et al., 2004
  • Kumar et al., 2010
  • Lodolini et al., 2017