Bioplastic Film From Black Soldier Fly Prepupae Proteins Used As Mulch: Preliminary Results

A protein-based film (PBF), obtained from black soldier fly prepupae proteins, was assessed for its agronomic performance as mulch. PBF was investigated in a potting experiment and compared with Mater-Bi (MB), polyethylene (PE) and bare soil. During the experiment, degraded surface area, weight and thickness of the film, water evaporated from the pot, and the soil microbiological content (SMC) were recorded. In addition, films were buried to assess their biodegradability and impact on SMC. During the mulching process, the PBF showed a significant degradation. In terms of evaporated water, the PBF performed similarly to MB and worse than PE. Regarding SMC, film of any nature caused an increase in the Clostridia spp. and a decrease of total mesophilic aerobic bacteria and fungi contents. When buried, only PBF recorded a faster biodegradability, showing a reduction of surface area, thickness and weight. PBF and MB highlighted a significant increase in contents of Clostridia spp., mesophilic aerobic bacteria and fungi. Our results reported, for the first time, the valorization of black soldier fly (BSF) prepupae proteins as a biodegradable film for mulching purposes. However, further study is needed to reduce the PBF biodegradability and allow it to be used for the most important mulched crops.