Table 1. Overview of the obtained studies and paired comparisons, target variables and main study characteristics.
| Total | Microbial biomass carbon | Microbial biomass nitrogen | Total PLFA | Basal respiration | Dehydrogenase activity | Metabolic quotient | Protease activity | Urease activity | |
|---|---|---|---|---|---|---|---|---|---|
| Number of studies | 56 studies | 42 studies | 21 studies | 8 studies | 29 studies | 17 studies | 22 studies | 3 studies | 7 studies |
| Number of paired comparisons | 149 | 100 | 49 | 22 | 66 | 40 | 40 | 7 | 18 |
| Experimental field comparisons | 75 | 54 | 28 | 11 | 42 | 18 | 26 | 2 | 5 |
| Farm comparisons | 74 | 46 | 21 | 11 | 24 | 22 | 14 | 5 | 13 |
| Experimental duration in years (Mean / Median) | 16.1 / 10.0 | 17.2 / 10.0 | 11.0 / 10.0 | 25.9 / 10.0 | 12.6 / 10.0 | 8.8 / 5.5 | 12.3 / 8.0 | 6.6 / 6.0 | 7.9 / 7.0 |
| Coverage of climatic zones+ | A, B, C, D | A, B, C, D | A, B, C, D | A, C, D | A, B, C, D | A, B, C, D | A, B, C, D | C | A, B, C |
| Coverage of continents * | 6 of 6 | 6 of 6 | 5 of 6 | 4 of 6 | 6 of 6 | 5 of 6 | 6 of 6 | 3 of 6 | 4 of 6 |
* all except Antarctica
+ A = Tropical/mega thermal climates, B = Dry climates, C = Temperate/mesothermal climates, D = Continental/Microthermal climates, E = Polar climates