Agronomic potential of a natural fertiliser based on fly larvae frass

A fertiliser has been developed from the digestates (frass) of the larvae of the black soldier fly (Hermetia illucens L.) when fed on plant waste. Produced by BSF Farms, this fertiliser is a rich source of organic matter and macroelements (N, P, K), as well as microelements such as Zn and Cu. Its trace-metal element (TME) content remains below the maximum permitted thresholds in Switzerland. The fertiliser has been tested in a greenhouse on three types of soil and two crops, ryegrass and lettuce. In terms of biomass production, the fertiliser produced the best results on the least fertile soil (acid and sandy soil). On this soil, the ryegrass and lettuce produced as much biomass with the BSF Farms fertiliser as with mineral fertilisers. This study suggests that the use of this fertiliser would be a promising strategy in conventional and/or organic farming.