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

Note:

H₂O-P_i and H₂O-P_o are water-extractable inorganic and organic phosphorus; NaHCO₃-P_i and NaHCO₃-P_o are NaHCO₃-extractable inorganic and organic phosphorus; NaOH-P_i and NaOH-P_o are NaOH-extractable inorganic and organic phosphorus; HCl-P_i and HCl-P_o are HCl-extractable inorganic and organic phosphorus.

Inorganic phosphorus (P_i) in each extract was determined by Murphy-Riley (1962). Organic phosphorus (P_o) in each extract was calculated as the difference between P_t and P_i. Values in parenthesis are the percentage of total manure phosphorus in each extract.

Residual P was determined using H₂SO₄-H₂O₂ digestion of the residual.