Table IV.

Orthophosphate concentration and pH in liquid medium with G. intraradices

	PO4− concentration			pH
Treatment	Initial	Final	Control	Final	Control
	μm
P-free	0.06	0.36	0.06	7.4 ± 0.18  a	5.0
Low-P	23	1.0	29	7.6 ± 0.14  a	5.5
Org-P	88	16	114	6.6 ± 0.22  b	4.7
High-P	2.5*103	2.6*103	2.9*103	6.8 ± 0.03  b	5.5
ANOVA				P = 0.002

Experiment 2. Final values were measured at the end of the experimental period (mean ± se, n = 4). Initial values were measured in media stored at −20°C. Liquid medium incubated in petri dishes without cultures was used as control (n = 2). The pH of the medium was set at 5.5 before incubation, but because the organic P was added after autoclaving, the pH could not be adjusted after this addition. The effect of P treatment on pH was tested with one-way ANOVA and different letters indicate significantly different values (P < 0.05, Fischer's lsd).