Aim of the research is the development of biodegradable polymeric materials based on hydrolyzed proteins, derived from waste products of the leather industry. Particular attention has been devoted to evaluate the application of such biobased materials in the agricultural practice of mulching. Biobased mulching films were generated in situ by low-pressure spraying of polymeric water dispersion on the soil; the mulches were tested in an ornamental cultivation carried out inside a greenhouse. The innovative spray films based on biodegradable components lasted in the field up to 12 months, keeping their mulching effect, thus guarantying weed suppression and preserving soil aggregates.