Effectiveness of Extractants for Bioavailable Phosphorus in Tropical Soils Amended with Sewage Sludge

Table 2

Mean extracted phosphorus by Mehlich-I, H₂SO₄, and resin in the two experiments described in the text: one with amendment of sewage sludge and the other with the amendment of sewage sludge and composted sewage sludge ().

Extractant	Depth (cm)
	0–10	10–20	20–40
	Sewage sludge
Mehlich-I	104.9^a	42.9^a	8.4^b
H2SO4	90.7^b	36.7^b	6.6^c
Resin	81.2^c	33.8^b	9.8^a
	Sewage sludge and composted sewage sludge
Mehlich-I	10.2^b	6.6^a	4.8^ba
H2SO4	8.4^c	5.4^b	4.0^b
Resin	13.6^a	7.5^a	6.0^a

For each experiment, values with the same letter within a column are not different (Tukey, ).