Evaluation of Biostimulants Based on Recovered Protein Hydrolysates from Animal By-products as Plant Growth Enhancers

Free amino acids-based biostimulants are gaining momentum in Europe for sustainable agriculture. They stimulate plant growth, improve crop productivity, and reduce reliance on harmful fertilizers. Enzymatic hydrolysis is used to develop biostimulants from animal by-products, such as greaves and protein-rich wastewater from processed animal proteins. The effectiveness of enzymatic hydrolysis depends on selecting the appropriate conditioning stage for the by-products, yielding protein in the range of 86% to 97%. These protein hydrolysates, with optimal amino acid compositions, are evaluated as biostimulants. Promising results show growth improvements of 17% to 31% in Chinese cabbage and lettuce seeds. The optimal dilution concentration ranges from 0.05% to 0.3%, depending on the protein hydrolysate used. The findings highlight the potential of these biostimulants to enhance plant growth and productivity while reducing environmental impact by replacing chemical fertilizers. They offer sustainable alternatives for promoting environmentally friendly practices in agriculture.