Table 1.
Concentrations of ammonium and nitrates, and ammonium-nitrate ratio of soil amended with BSF frass and commercial organic fertilizers.
| Parameter | Time (days) | Season 2019A (Short rains) | Season 2019B (Long rains) | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Control | BSFFF | SAFI | p value | Control | BSFFF | SAFI | p value | ||
| Ammonium (mg kg−1) | 0 | 1.1 ± 0.3c | 300.6 ± 34.6a | 128.2 ± 10.6b | *** | 1.4 ± 0.3c | 402.2 ± 46.4a | 171.5 ± 14.1b | *** |
| 15 | 2.2 ± 0.3b | 207.1 ± 75.3a | 96.3 ± 5.7ab | * | 3.8 ± 0.5b | 353.6 ± 128.3a | 164.3 ± 9.9ab | * | |
| 30 | 0.8 ± 0.0b | 119.9 ± 27.6a | 34.0 ± 5.6b | ** | 2.4 ± 0.0b | 359.7 ± 82.9a | 79.3 ± 7.5b | ** | |
| 60 | 50.7 ± 18ab | 128.9 ± 29.5a | 6.0 ± 4.2b | * | 220.3 ± 48.1ab | 490.7 ± 112.5a | 22.1 ± 15.6ab | * | |
| 90 | 0.8 ± 0.0b | 51.3 ± 16.6a | 3.4 ± 1.5b | * | 2.1 ± 0.1b | 145.2 ± 46.9a | 9.5 ± 4.3b | * | |
| 125 | 2.1 ± 0.7b | 71.9 ± 17.6a | 1.8 ± 0.6b | *** | 6.4 ± 2.0b | 215.7 ± 52.7a | 5.5 ± 1.8b | *** | |
| Nitrate (mg kg−1) | 0 | 0.2 ± 0.0b | 3.9 ± 1.3b | 208.1 ± 36.3a | *** | 0.4 ± 0.1b | 7.5 ± 2.5b | 400.2 ± 69.8a | *** |
| 15 | 2.9 ± 0.3b | 1.2 ± 0.4b | 230.3 ± 6.7a | *** | 5.5 ± 0.7b | 2.4 ± 0.7b | 444.8 ± 12.9a | *** | |
| 30 | 3.2 ± 0.5b | 2.1 ± 0.4b | 130.7 ± 11.8a | *** | 9.1 ± 1.4b | 6.1 ± 1.3b | 377.8 ± 34.0a | *** | |
| 60 | 9.5 ± 2.1 | 6.5 ± 1.9 | 91.5 ± 37.1 | ns | 14.1 ± 3.1 | 9.7 ± 2.8 | 136.0 ± 55.1 | ns | |
| 90 | 13.9 ± 1.9b | 5.3 ± 1.9b | 234.1 ± 47.7a | ** | 18.1 ± 2.5b | 6.9 ± 2.5b | 305.2 ± 62.1a | ** | |
| 125 | 8.4 ± 2.0b | 9.1 ± 0.5b | 170.2 ± 60.3a | * | 14.8 ± 3.5b | 16.0 ± 0.9b | 298.8 ± 105.8a | * | |
| Ammonium/Nitrate ratio | 0 | 5.7 ± 1.4a | 90.0 ± 21.3a | 0.66 ± 0.1b | ** | 4.0 ± 1.0b | 62.6 ± 14.8a | 0.5 ± 0.1b | ** |
| 15 | 0.8 ± 0.1a | 165.1 ± 10.6a | 0.42 ± 0.0b | *** | 0.70 ± 0.1b | 145.9 ± 9.3a | 0.4 ± 0.0b | *** | |
| 30 | 0.3 ± 0.0b | 57.3 ± 3.6a | 0.27 ± 0.1b | *** | 0.3 ± 0.1b | 59.4 ± 3.8a | 0.2 ± 0.0b | *** | |
| 60 | 5.1 ± 1.1ab | 22.1 ± 7.2a | 0.27 ± 0.3b | * | 15.6 ± 0.2ab | 56.5 ± 18.5a | 0.7 ± 0.6b | * | |
| 90 | 0.1 ± 0.0b | 13.1 ± 5.2a | 0.01 ± 0.0b | * | 0.1 ± 0.0b | 28.6 ± 11.3a | 0.03 ± 0.0b | * | |
| 125 | 0.3 ± 0.1b | 8.1 ± 2.2a | 0.01 ± 0.0b | ** | 0.5 ± 0.2b | 13.8 ± 3.8a | 0.02 ± 0.0b | ** | |
*** p < 0.001, **p < 0.01, *p < 0.05, ns = not significant at p ≥ 0.05, BSFFF = Black soldier fly frass fertilizer, SAFI = commercial organic fertilizer, control = unamended soil. Within the same row and per parameter, means (± standard error) with the same letters are not significantly different at p ≥ 0.05, n = 3.