In the present research biocomposites based on extracts of collagen and keratin recovered from the leather industry by-products were made and the specific properties for applications in agriculture and industry were studied. To this aim, collagen and keratin have been extracted from bovine leather and sheep wool by-products and have been added and crosslinked with recognized compounds for reduced environmental impact (glycerol, vegetable tanning extract, essential oils with fungicidal properties and insecticides). The biocomposite properties were evaluated on the basis of complex analytical investigations on chemical structure, texture, contact angle, mechanical resistance, water vapor permeability and water absorption, biodegradation, germination and plant biomass growth. The biocomposites have demonstrated pelliculogenic properties and nitrogen controlled release to stimulate germination and nutrition of rape seedlings, which promotes them for agricultural applications, but also other surface properties have been identified, for industrial applications, for example in leather finishing for special destinations. Addition of odorous principles with controlled release recommends this type of biocomposites for environmentally friendly products, maintenance of cleaning, etc.