Table 4.
Database as related to climatic zones and nutrient inputs.
| Tropical climate | Dry climate | Continental climate | Oceanic climate | |
|---|---|---|---|---|
| Nr of studiesa | 70 | 71 | 17 | 8 |
| Nr of pairwise comparisons | 686 | 718 | 152 | 110 |
| Coverage of continents | 5 | 5 | 3 | 3 |
| Average N applied (kg ha−1) (mean/median ± SD) | 90.8/60 ± 88.2 | 120.5/90 ± 132.1 | 78.2/80 ± 58.3 | 65.3/47.5 ± 45.4 |
| Average P applied (kg ha−1) (mean/median ± SD) | 47.3/38 ± 35.1 | 48.6/35.7 ± 40.7 | 37.8/34.9± 29.4 | 55.0/70.0 ± 30.2 |
| Average OM% (mean/median ± SD) | 1.69/0.88 ± 1.59 | 1.02/0.95 ± 0.79 | 2.37/1.8 ± 1.85 | 4.82/4.18 ± 2.85 |
| Average pH (mean/median ± SD) | 6.66/6.80 ± 1.20 | 7.81/7.80 ±0.34 | 7.16/7.15 ± 0.61 | 5.55/5.50 ± 0.98 |
Averages for fertilizer applications were only calculated if fertilizers were applied.
a
Five of the studies analyzed were excluded because they could not be assigned unequivocally to one climate zone.