Table 4.
Effects of black soldier fly (BSF) frass fertilizer, commercial organic and mineral (urea) fertilizers on maize stover yields, and phosphorus and potassium uptake at maturity.
| Fertilizer treatments | SEASON 2019A (Short rain) | SEASON 2019B (Long rain) | ||||||
|---|---|---|---|---|---|---|---|---|
| Stover yield(t ha-1) | Nutrients uptake (kg ha-1) | Stover yield(t ha-1) | Nutrients uptake (kg ha-1) | |||||
| Phosphorus | Potassium | Phosphorus | Potassium | |||||
| Types of fertilizers | ||||||||
| Control | 5.9 ± 0.78 | 4.2 ± 0.22b | 77.6 ± 10.3b | 5.8 ± 1.2 | 5.4 ± 1.3b | 63.6 ± 13.7b | ||
| 2.5 BSF | 8.4 ± 0.63 | 12.7 ± 2.1a | 128.5 ± 25ab | 8.1 ± 0.6 | 12.7 ± 1.3ab | 122.0 ± 14.8ab | ||
| 5 BSF | 9.6 ± 0.76 | 12.9 ± 1.9a | 160.5 ± 15.3ab | 9.8 ± 2.4 | 16.3 ± 2.5a | 163.8 ± 34.5ab | ||
| 7. 5BSF | 7.9 ± 1.05 | 13.3 ± 1.2a | 118.9 ± 10.9ab | 11.5 ± 2.3 | 18.6 ± 2.8a | 173.4 ± 37.0ab | ||
| 2.5 SAFI | 8.5 ± 0.70 | 10.7 ± 2.2ab | 97.4 ± 18.7ab | 7.2 ± 1.9 | 10.2 ± 1.5ab | 123.5 ± 32.5ab | ||
| 5 SAFI | 6.4 ± 0.44 | 11.1 ± 1.2ab | 144.0 ± 22.8ab | 7.4 ± 0.6 | 11.8 ± 1.8ab | 110.1 ± 21.6ab | ||
| 7.5 SAFI | 8.8 ± 1.49 | 11.6 ± 2.1ab | 171.2 ± 10.6a | 10.6 ± 1.8 | 14.6 ± 1.8ab | 212.5 ± 33.5a | ||
| Fertilizer | ns | * | * | ns | ** | * | ||
| Nitrogen fertilizer treatments | ||||||||
| 30N BSF | 6.8 ± 1.78 | 10.6 ± 0.9ab | 104.9 ± 20.9ab | 7.7 ± 0.32abc | 11.7 ± 0.6abc | 125.1 ± 21.6ab | ||
| 60N BSF | 8.3 ± 0.83 | 13.6 ± 1.8ab | 109.4 ± 12.8ab | 8.9 ± 0.26ab | 14.6 ± 2.4ab | 115.5 ± 1.8ab | ||
| 100N BSF | 9.6 ± 1.41 | 16.4 ± 2.0a | 179.0 ± 37.5a | 10.3 ± 0.10a | 17.4 ± 1.0a | 189.2 ± 30.9a | ||
| 30N SAFI | 6.1 ± 0.60 | 8.7 ± 0.6ab | 83.3 ± 14.1ab | 5.0 ± 0.34c | 7.2 ± 0.9bc | 69.0 ± 13.5b | ||
| 60N SAFI | 7.6 ± 0.97 | 7.2 ± 1.1bc | 98.0 ± 19.9ab | 7.3 ± 0.27abc | 8.1 ± 0.4bc | 94.1 ± 16.8b | ||
| 100N SAFI | 7.7 ± 0.71 | 10.8 ± 1.3ab | 119.0 ± 4.4ab | 8.0 ± 0.20abc | 11.8 ± 1.3abc | 124.7 ± 2.7ab | ||
| 30N UREA | 9.0 ± 1.23 | 10.6 ± 0.8ab | 143.2 ± 28.5ab | 7.1± 0.4babc | 12.7 ± 1.1abc | 113.3 ± 7.3ab | ||
| 60N UREA | 6.4 ± 0.89 | 10.0 ± 2.6ab | 91.6 ± 11.3ab | 9.1± 0.04ab | 12.6 ± 3.3abc | 129.5 ± 5.5ab | ||
| 100N UREA | 8.1 ± 0.54 | 12.6 ± 2.3ab | 121.4 ± 11.1ab | 7.7± 0.42abc | 13.3 ± 2.9abc | 118.3 ± 13.6ab | ||
| Control | 5.9 ± 0.78 | 4.2 ± 0.2c | 77.6 ± 10.3b | 5.8 ± 1.2bc | 5.4 ± 1.3c | 63.6 ± 13.7b | ||
| ns | ** | * | ** | ** | *** | |||
***p < 0.001, **p < 0.01, *p < 0.05, ns, not significant; 2.5, 5, and 7.5, application rates of organic fertilizers at 2.5, 5, and 7.5 t ha-1; 30N, 60N, and 100N, application rates of fertilizers at rates equivalent to 30, 60, and 100 kg N ha-1 supplemented with 60 kg P ha-1 and 50 kg K ha-1; BSF, black soldier fly frass fertilizer; SAFI, commercial organic fertilizer.