Table 4: Soil P distributions among the various fractions at the beginning ( ) and after 90 days of incubation (90 d).

BiosolidsSoil P fractions1
H2OKCl NaOHP0HClResidual
T 090 T 090 dT 090 dT 090 dT 090 dT 090 d

Average P concentration (mg kg−1)
Control9.5 (0.9)38.1 (0.7)2.7 (0.2)3.7 (0.3)760 (68)726 (61)67 (6.0)95 (8.0)68 (6.0)43 (3.6)210 (19)311 (26)
ATAD45 (3.8)14 (1.1)3.9 (0.3)10 (0.9)683 (57)799 (67)66 (5.5)72 (6.0)71 (6.0)46 (3.8)320 (27)249 (21)
OC East Cake57 (4.3)15 (1.1)8.9 (0.7)10 (0.8)779 (59)773 (59)78 (6.0)71 (5.3)79 (6.0)48 (3.7)315 (24)400 (30)
JEA Cake18 (1.6)7.4 (0.7)3.3 (0.3)6.3 (0.5)764 (67)763 (67)51 (4.5)73 (6.4)90 (7.9)48 (4.2)214 (19)242 (21)
Tampa12 (1.0)9.6 (0.8)4.5 (0.4)7.3 (0.6)783 (65)775 (65)74 (6.2)454 (3.8)89 (7.5)53 (4.4)234 (19)307 (26)
WPB21 (1.8)13 (1.1)5.5 (0.5)6.5 (0.5)775 (65)794 (66)70 (5.9)78 (6.5)79 (6.6)56 (4.7)243 (20)246 (21)
OC South Cake27 (2.2)12 (1.0)6.9 (0.6)9.3 (0.8)761 (62)762 (62)77 (6.3)56 (4.5)83 (6.8)48 (3.9)271 (22)339 (28)
Disney15 (1.2)9.5 (0.8)3.3 (0.3)5.4 (0.4)786 (63)853 (69)35 (2.8)63 (5.1)86 (6.9)55 (4.4)319 (26)257 (21)
TSP39 (3.3)16 (1.4)6.2 (0.5)6.8 (0.6)739 (62)823 (74)54 (4.5)67 (6.0)74 (6.2)49 (4.4)276 (23)156 (14)

H2O and KCl represent water-soluble and exchangeable P fractions, respectively; and NaOHP0 represent the Al- and Fe-bound inorganic and organic P; HCl is Ca-bound P; Residual is mineral-associated inorganic P.
Values represent average P concentration of samples incubated at 20°C and 32°C.
Data in parenthesis are % of total P.