Table 4.
Statistical analysis for beneficial soil organisms and plant traits in the three field experiments.
| Organisms | Type of measurement | Statistical method | COMBINATIONa | PERFORMANCE-1a | PERFORMANCE-2a |
|---|---|---|---|---|---|
| Bacteria | CFU quantification I | One–way ANOVA (Tukey's HSD test); Kruskal-Wallis (Dunn's test) | F(1, 6) = 0.1526, n.s | F(1, 2) = 2.571, ** | F(3, 15) = 0.991, n.s. |
| CFU quantification II | One–way ANOVA (Tukey's HSD test); Kruskal-Wallis (Dunn's test) | –b | F(5, 12) = 3.675, ** | F(3, 16) = 0.656, n.s. | |
| CFU quantification III | One–way ANOVA (Tukey's HSD test); Kruskal-Wallis (Dunn's test) | – | F(4, 15) = 2.311, n.s. | F(3, 16) = 1.570, n.s. | |
| AMF | Quantification of INOQ Topc | One–way ANOVA | F(2, 9) = 10.42, ** | Not contributed | – |
| Quantification of SAF22c | T-tests | T = 10.377 *** | Not contributed | – | |
| Quantification of INOQ Top in combination samplesc | One–way ANOVA | F(5, 18) = 3.712, * | Not contributed | F(4, 36) = 0.571, n.s. | |
| EPN | EPN presence: pre-inoculation (baseline) | One–way ANOVA (Tukey's HSD test) | F(7, 24) = 1.273, n.s. | F(6, 21) = 0.525, n.s. | F(4, 40) = 0.281, n.s. |
| EPN presence: post-augmentation | One–way ANOVA (Tukey's HSD test) | F(7, 24) = 4.604, ** | F(6, 21) = 2.194, § | F(6, 21) = 2.888, * | |
| EPN activity: insect-baits | One–way ANOVA (Tukey's HSD test) | F(7, 24) = 3.317, * | F(6, 21) = 1.243, n.s. | F(6, 21) = 0.722, n.s. | |
| Free-living nematodes: pre-inoculation | One–way ANOVA (Tukey's HSD test) | F(7, 24) = 1.051, n.s. | F(6, 21) = 0.498, n.s. | F(6, 21) = 0.119, n.s. | |
| Free-living nematodes: post-augmentation | One–way ANOVA (Tukey's HSD test) | F(7, 24) = 0.395, n.s. | F(6, 21) = 1.025, n.s. | F(6, 21) = 0.341, n.s. | |
| Nematophagous fungi: pre-inoculation | One–way ANOVA (Tukey's HSD test) | F(7, 24) = 0.675, n.s. | F(6, 21) = 0.288, n.s. | F(6, 21) = 0.618, n.s. | |
| Nematophagous fungi: post-augmentation | One–way ANOVA (Tukey's HSD test) | F(7, 24) = 5.820, n.s. | F(6, 21) = 1.384, n.s. | F(6, 21) = 0.582, n.s. | |
| Plants | Height (at harvest) | One–way ANOVA (Tukey's HSD test) | – | – | F(8, 72) = 1.009, n.s. |
| Density (% plot covered by plants at harvest) | One–way ANOVA (Tukey's HSD test) Kruskal-Wallis (Dunn's test) | – | F(7, 88) = 17.219, *** | F(8, 72) = 0.756, n.s. | |
| Chlorophyll activity (N-tester) | One–way ANOVA (Tukey's HSD test) | – | – | F(8, 72) = 0.161, n.s. | |
| Yield (g seeds/plot) | One–way ANOVA (Tukey's HSD test) | – | F(7, 23) = 2.069, ** | F(8, 72) = 0.026, n.s. | |
| Thousand-seed weight (TSW) | One–way ANOVA (Tukey's HSD test) | – | – | F(8, 72) = 0.129, n.s. | |
| Protein content | One–way ANOVA (Tukey's HSD test) | – | – | F(8, 72) = 0.300, n.s. |
a
Data are presented as the statistical values, degree of freedom and probability levels:
§
P < 0.1,
*
P < 0.05,
**
P < 0.01,
***
P < 0.001, n.s., not significant.
b
For these variables, obtained data were not representative because of highly heterogeneous growth of the wheat plants within the plots following frit fly damage and thus were not considered for statistical analysis.
c
Statistics corresponding to data from two sets of primers, i.e., by Alkan et al. (2006) for INOQ Top, and Bender et al. (unpublished) for SAF22.