The concentration of phosphorus compounds in sequential extracts of animal manures from the modified Hedley fraction procedure determined by Murphy-Riley (1962).

Note:†H2O-Pi and H2O-Po are water-extractable inorganic and organic phosphorus; NaHCO3-Pi and NaHCO3-Po are NaHCO3-extractable inorganic and organic phosphorus; NaOH-Pi and NaOH-Po are NaOH-extractable inorganic and organic phosphorus; HCl-Pi and HCl-Po are HCl-extractable inorganic and organic phosphorus.‡Inorganic phosphorus (Pi) in each extract was determined by Murphy-Riley (1962). Organic phosphorus (Po) in each extract was calculated as the difference between Pt and Pi. Values in parenthesis are the percentage of total manure phosphorus in each extract.¶Residual P was determined using H2SO4-H2O2 digestion of the residual.