Table 3.

Effect of alum sludge incorporation to a highly acidic soil on soil P fractions of the entire soil volume (0–15 cm depth) after second wheat crop in a pot trial (Cox et al. (1997))

Sludge rate	Loosely bound-P (plant available soil P)	Al-P	Fe–P	Ca-P
g/kg soil	mg P/kg soil)
0	3.5	111.8	47.6	27.7
4.45	2.4	117.0	45.4	25.5
8.9	1.7	117.3	50.7	21.3
17.8	2.0	121.2	55.8	25.5
ANOVA	*	NS**	*	NS**

^*ANOVA significant at the 0.01 probability level (LSD values were not reported by Cox et al. (1997)); ^** NS = Not significant