Table 4.
Compost maturity indices of frass fertilizer produced by different edible insect species.
| Source of frass fertilizer | pH | Electrical conductivity (mS cm−1) | Ammonium/nitrate ratio | C/N ratio | Seed germination rate | Gemination index |
|---|---|---|---|---|---|---|
| (%) | ||||||
| Hermertia illucens | 7.5 ± 0.09c | 16.0 ± 1.58b | 3.9 ± 3.83b | 13.2 ± 0.39b | 93.3 ± 3.3a | 267.1 ± 91.7a |
| Tenebrio molitor | 6.5 ± 0.05e | 6.7 ± 0.63f | 0.006 ± 0.00b | 20.0 ± 0.35ab | 56.7 ± 14.5c | 27.9 ± 6.2e |
| Scapsipedus icipe | 7.4 ± 0.02c | 11.5 ± 0.07cde | 0.005 ± 0.00b | 17.4 ± 0.35ab | 63.3 ± 3.3bc | 31.2 ± 1.6e |
| Bombyx mori | 8.1 ± 0.02a | 10.0 ± 0.69def | 1.00 ± 0.00b | 19.1 ± 4.94ab | 60.0 ± 5.8bc | 29.5 ± 2.8e |
| Gryllus bimaculatus | 6.6 ± 0.05e | 9.0 ± 0.34ef | 0.12 ± 0.00b | 18.6 ± 0.32ab | 76.7 ± 3.3abc | 37.8 ± 1.6de |
| Gonimbrasia krucki | 4.6 ± 0.04f | 15.5 ± 0.23b | 79.7 ± 10.1a | 22.9 ± 0.14a | 86.7 ± 3.3ab | 47.8 ± 6.2cd |
| Pachnoda sinuata | 8.3 ± 0.03a | 25.1 ± 0.18a | 1.58 ± 0.009b | 14.6 ± 0.56b | 96.7 ± 3.3a | 66.1 ± 8.5bc |
| Schistocerca gregaria | 6.9 ± 0.03d | 13.9 ± 0.16bc | 0.003 ± 0.00b | 19.5 ± 0.47ab | 23.3 ± 6.7d | 5.8 ± 1.6f |
| Oryctes rhinoceros | 7.9 ± 0.02b | 13.2 ± 0.25bcd | 0.15 ± 0.05b | 14.6 ± 0.85b | 93.3 ± 6.7a | 73.9 ± 12.4b |
| χ2-value | 5195.2 | 330.4 | 424.4 | 26.5 | 105.9 | 1602.0 |
| df | 8 | 8 | 8 | 8 | 8 | 8 |
| p value | ≤ 0.001 | ≤ 0.001 | ≤ 0.001 | ≤ 0.001 | ≤ 0.001 | ≤ 0.001 |
C/N ratio = ratio of total organic carbon to total nitrogen. In the same column, means (± standard error) followed by the same letters are not significantly different at p ≤ 0.05, n = 3.