Table 1. Fertilizer treatments and amounts of nutrients (kg ha-1) added in different treatments in the study area.
Nutrient
Treatment 1) N P K Ca Mg B
Cont 0 0 0 0 0 0
PK 0 54 102 156 3 1.8
PK+N 110 54 102 172 6 1.8
ApaBio 0 79 102 270 123 0
ApaBio+N 110 79 102 286 126 0
Ash 0 135 225 1440 225 1.8
Ash+N 110 135 225 1456 228 1.8
1) PK = PK for peatlands 600 kg ha-1, (9% P, 17% K, 0.3% B); Apa =Apatite (Ca5(PO4)3(OH,F,Cl)) 385 kg ha-1, (16% P, 35% Ca, 1% Mg); Bio = Biotite (K(Fe, Mg)3AlSi3O10(F, OH)2) 1700 kg ha-1, (1% P, 6% K, 8% Ca, 7% Mg); Ash = Wood ash 4500 kg ha-1, dust-like wood ash from a heating plant in Oulu city, (3% P, 5% K, 32% Ca, 5% Mg, 0.04% B); N = Ammonium nitrate with lime 400 kg ha-1, (13% NH4-N, 13% NO3-N).
Table 2. Mean foliar nutrient concentrations before and 9, 14 and 26 years after the fertilization treatments. Statistically different means are marked with different letters (Bonferroni test, p-value < 0.05). See Table 1 for the information of treatments. Means below critical levels (deficiency limit) for N (12 g kg–1), P (1.3 g kg–1), K (4.0 g kg–1) (see Paarlahti et al., 1971, Reinikainen et al., 1998) are marked with bold letters.
  Years after fertilization
0 9 14 26
Nutrient Treatment Mean S.E. Mean S.E. Mean S.E. Mean S.E.
N, g kg–1 Cont 13.2 0.7 13.6 0.7 14.5 0.4 15.2 0.5
PK 13.1 0.7 14.1 0.5 13.9 0.2 15.5 0.4
ApaBio 12.8 0.2 13.5 0.3 14.0 0.3 15.9 0.6
Ash 12.5 0.7 14.0 0.2 14.4 0.4 15.3 0.5
P, g kg–1 Cont 1.18 0.04 1.23a 0.04 1.36a 0.08 1.24a 0.05
PK 1.14 0.04 1.64b 0.04 1.59b 0.04 1.41ab 0.02
ApaBio 1.24 0.07 1.55b 0.03 1.58b 0.04 1.47b 0.06
Ash 1.12 0.05 1.57b 0.03 1.61b 0.01 1.36ab 0.05
K, g kg–1 Cont 3.19 0.11 3.01a 0.06 3.10a 0.06 3.00a 0.08
PK 3.26 0.01 4.34b 0.23 3.99b 0.14 3.70b 0.10
ApaBio 3.11 0.05 3.86b 0.17 3.77b 0.16 3.56ab 0.17
Ash 2.96 0.21 4.23b 0.12 4.26b 0,17 4.05b 0.14
Ca, g kg–1 Cont 2.01 0.12 2.03 0.16 1.68 0.10 2.21 0.12
PK 1.96 0.09 2.11 0.16 1.73 0.08 1.94 0.11
ApaBio 1.97 0.21 2.06 0.11 1.63 0.10 1.99 0.10
Ash 2.03 0.16 2.08 0.08 1.74 0.07 2.15 0.13
Mg, g kg–1 Cont 1.37 0.05 1.31a 0.04 1.42 0.04 1.29 0.03
PK 1.36 0.03 1.01b 0.04 1.36 0.04 1.24 0.06
ApaBio 1.37 0.07 1.17a 0.04 1.35 0.05 1.23 0.05
Ash 1.32 0.07 1.01b 0.03 1.25 0.04 1.16 0.04
B, mg kg–1 Cont 45 4.1 26 0.8 21 1.1 22 1.0
PK 42 5.1 27 0.9 23 1.0 23 1.0
ApaBio 46 9.2 23 0.8 20 07 22 0.9
Ash 41 3.3 27 0.8 24 1.1 24 1.3
Table 3. The ratios of N:P and N:K in Scots pine needles by treatments during the study period of 26 years. See Table 1 for the information of treatments. Optimal values for N:P = 10–11, and for N:K = 3–4 (e.g. Puustjärvi 1962a,b; Ingestad 1979). Statistically different means between treatments are marked with different letters (Bonferroni test, p-value < 0.05).
N:P ratio
  Years from fertilization
Treatment 0 9 14 26
Cont 11.4 11.2 a 10.9 a 12.5
PK 11.6 8.7 b 8.8 b 11.0
ApaBio 10.3 8.7 b 8.9 b 10.9
Ash 10.8 8.9 b 9.0 b 11.4
N:K ratio
  Years from fertilization
0 9 14 26
Cont 4.1 4.5 a 4.7 a 5.1 a
PK 4.0 3.3 b 3.5 b 4.2 ab
ApaBio 4.1 3.5 b 3.8 b 4.5 ab
Ash 4.3 3.3 b 3.4 b 3.8 b
Table 4. Results of Greenhouse-Geisser tests in repeated measures ANOVA. Df-values, F values, and adjusted p-values for the time factor and the interaction of fertilization treatment and time. The response variables are the foliar N, P and K concentations and periodic (5 year) stand growth.
Variable Effect df F p
N Time 1.61 100.2 <0.001
Time* treatment 9.63 1.28 0.267
P Time 1.70 169.5 <0.001
Time* treatment 10.2 2.15 0.033
K Time 1.90 91.8 <0.001
Time* treatment 11.39 5.93 <0.001
Stand
growth 		Time 2.10 60.37 <0.001
Time* treatment 12.58 4.80 <0.001
1

Fig. 1. The development of annual volume growth of Scots pine in 1985–2010 by covariance analysis (pre-treatment volume growth as covariate). See Table 1 for the information of treatments. The comparison between fertilizers including P and K. Statistically significant differences in the total stand growth during the study period (p < 0.05 in Bonferroni test): Control vs. PK; Control vs. ApaBio; Control vs. Ash; PK vs. Ash; ApaBio vs. Ash.

Table 5. The stand characteristics before and after cutting in 2010 and logging removals by treatments. See Table 1 for the information of treatments. Covariate adjusted values (pre-treatment volume as covariate); statistically different means are marked with different letters.
Treatment Growing stock before cutting, m3 ha-1 Removal in cutting, m3 ha-1
  Volume Saw logs   Total Saw logs Pulp wood
Cont 93 a 8 43 a 1 39
PK 148 b 42 66 ac 9 54
PK+N 143 bd 36 68 cbe 10 54
ApaBio 151 bd 26 77 cbe 5 66
ApaBio+N 143 b 31 67 ac 8 55
Ash 182 c 60 93 de 15 73
Ash+N 177 cd 56 83 cbe 15 63
Growing stock after cutting, m3 ha-1
  Total Saw logs Pulp wood  
Cont   48 a 8 38
PK 79 bc 35 43
PK+N 72 b 26 45
ApaBio 72 b 22 48
ApaBio+N 73 b 25 47
Ash 90 cd 45 44
Ash+N 93 cd 42 49
2

Fig. 2. Equivalent annual incomes, EAIs associated with alternative treatments, € ha–1 year–1. Discount rate 3%, 4% and 5%. Bars represent averages and line segments illustrate standard deviations divided by two (i.e. positive tops). With 5% discount rate asterisks indicate statistically significant differences (p < 0.05) compared to Control. See Table 1 for the information of treatments. View larger in new window/tab.