Table 6.

Results of isotopic exchange analyses for the study sites Mangfallgebirge, Tuttlingen, Schänis, and Bärenthal (mean ± standard deviation, n = 3). Water extractable P (P_w) and total inorganic P (P_i). Fitting parameters (m and n) describing the decrease of radioactivity in the solution with time, amount of P isotopically exchangeable within 1 min (E_1min), between 1 min and 1 day (E_1min-1 day), between 1 day and 3 months (E_{1day-3 months}), and amount of P not exchangeable within 3 months (E_>3 months)

	Pw (µg P g−1 soil)	Pi (µg P g−1 soil)	m	N	E1min ( µg P g−1 soil)	E1min-1 day ( µg P g−1 soil)	E1day-3 months ( µg P g−1 soil)	E> 3 months ( µg P g−1 soil)
Mangfallgebirge S1
Ah1	2.97 ± 0.86	134.6	0.51 ± 0.18	0.59 ± 0.03	7.5 ± 4.5	93.4 ± 11.6	30.4 ± 14.1	3.3 ± 1.9
Bk	0.19 ± 0.21	48.2	0.03 ± 0.01	0.59 ± 0.10	5.2 ± 4.5	33.8 ± 4.7	8.0 ± 7.0	1.2 ± 1.4
Mangfallgebirge S2
Ah	0.66 ± 0.29	138.9	0.17 ± 0.06	0.61 ± 0.07	4.4 ± 2.6	92.3 ± 14.5	37.9 ± 13.2	4.3 ± 3.3
AC	0.48 ± 0.13	104.9	0.23 ± 0.07	0.40 ± 0.87	2.2 ± 0.9	27.2 ± 15.7	39.0 ± 10.8	36.4 ± 24.8
Tuttlingen NE
Ah1	2.42 ± 0.22	174.8	0.35 ± 0.05	0.33 ± 0.01	6.8 ± 0.9	45.7 ± 5.7	61.0 ± 1.6	61.3 ± 8.1
BA	0.82 ± 0.13	103.8	0.19 ± 0.01	0.37 ± 0.02	4.1 ± 0.7	35.0 ± 2.9	39.9 ± 1.7	24.9 ± 3.4
C1	0.77 ± 0.03	141.9	0.16 ± 0.01	0.35 ± 0.00	4.7 ± 0.2	37.6 ± 1.1	52.5 ± 0.5	47.1 ± 1.6
Schänis
Ah1	1.13 ± 0.21	140.8	0.36 ± 0.13	0.43 ± 0.03	3.3 ± 0.7	44.0 ± 9.8	60.5 ± 2.9	33.0 ± 12.1
Ah2	0.13 ± 0.07	103.0	0.14 ± 0.05	0.46 ± 0.07	0.9 ± 0.4	20.4 ± 11.9	42.8 ± 11.4	38.9 ± 23.5
Bw1	0.09 ± 0.01	77.7	0.05 ± 0.01	0.42 ± 0.03	1.8 ± 0.2	24.3 ± 2.8	33.7 ± 1.7	18.0 ± 4.0
Bärenthal
Ah	1.14 ± 0.15	54.0	0.35 ± 0.02	0.40 ± 0.04	3.2 ± 0.4	25.1 ± 4.3	18.3 ± 1.2	7.5 ± 3.5
BA	0.05 ± 0.03	48.0	0.02 ± 0.00	0.40 ± 0.03	2.3 ± 1.3	19.6 ± 7.2	17.0 ± 3.5	9.0 ± 5.1
Bw	0.003 ± 0.000	92.0	0.01 ± 0.00	0.32 ± 0.03	0.3 ± 0.0	2.7 ± 0.4	8.5 ± 2.5	80.5 ± 2.8