TABLE 1.
Environmental differences between organic and conventionally managed fields in Monteverde and San Vito, Costa Rica, by field type or by F × Ra
| Variable | Mean ± SE (n) by field type for location: |
F1,14 | P | Effect | |||||
|---|---|---|---|---|---|---|---|---|---|
| Monteverde |
San Vito |
||||||||
| Conventional (8) | Minimal (1) | Organic (4) | Conventional (5) | Minimal (2) | Organic (5) | ||||
| Shade (%) | 9 ± 3 A | <1 | 64 ± 11 B | 36 ± 10 AB | 17 | 53 ± 8 B | 6.40 | 0.0241 | F × R |
| Shade tree richness | 0.5 ± 0.3 A | 0 | 4.5 ± 0.6 B | 4.0 ± 1.2 B | 5 | 4.8 ± 1.9 B | 12.50 | 0.0039 | F × R |
| Leaf litter depth (cm) | 2.3 ± 0.7 B | 1.3 | 4.8 ± 1.2 A | 2.2 ± 0.4 B | 4.7 | 3.6 ± 0.6 A | 6.42 | 0.0248 | Field |
| pH in water | 5.18 ± 0.15 A | 5.30 | 6.09 ± 0.06 B | 5.25 ± 0.07 A | 5.20 | 5.72 ± 0.3 B | 17.07 | 0.0010 | Field |
| NO3−-N (kg/ha) | 164 ± 31 B | 74 | 54 ± 15 A | 103 ± 5 B | 31 | 33 ± 6 A | 33.81 | <0.0001 | Field |
| Cu concn (ppm) | 1.87 ± 0.21 A | 1.76 | 2.52 ± 0.45 B | 3.94 ± 0.32 C | 3.73 | 6.25 ± 0.86 D | 9.12 | 0.0092 | Field |
| Ca2+ concn (ppm) | 1,769 ± 203 A | 1012 | 3,570 ± 580 B | 1,622 ± 323 A | 706 | 2,199 ± 667 AB | 12.87 | 0.0030 | F × R |
| Mg2+ concn (ppm) | 89 ± 7 A | 81 | 294 ± 78 C | 185 ± 35 B | 142 | 185 ± 55 B | 9.67 | 0.0077 | F × R |
a
F × R, field type and field type by region. Means that share a letter did not differ statistically by Tukey’s HSD test. Values are also shown for fields with minimal conventional management for comparison, but these were too few to include in the statistical analysis.