Table 4. Concentration of phosphorus compounds in two steps extracts of animal manures determined by Murphy-Riley (1962).

P fraction†	Dairy manure	Swine manure	Broiler litter
		g P kg−1 of dry matter
	Inorganic P
NaHCO3-Pi	3.6 (48%)	4.6 (14%)	3.5 (22%)
NaOH/EDTA-Pi	0.3 (4%)	2.3 (7%)	2.8 (18%)
∑ Pi fractions	3.9 (52%)	6.9 (21%)	6.3 (40%)
	Organic P
NaHCO3-Po	0.3 (4%)	0.3 (1%)	1.4 (9%)
NaOH/EDTA-Po	2.2 (29%)	19.0 (59%)	5.7 (36%)
∑ Po fractions	2.5 (33%)	19.3 (60%)	7.1 (45%)
Residual P¶	1.1 (15%)	6.2 (19%)	2.4 (15%)
Total P	7.5	32.4	15.8

Note:

^†NaHCO₃-P_i and NaHCO₃-P_o are NaHCO₃-extractable inorganic and organic phosphorus; NaOH/EDTA-P_i and NaOH/EDTA-P_o are NaOH/EDTA-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.