On-farm experimental trial of self-produced fermented plant biostimulants on rootstock vigor and soil fertility: agronomic impacts, feasibility and sustainability at La Noria farm ; Expérimentation de biostimulants fermentés auto-produits sur la vigueur de porte-greffes et la fertilité du sol : impacts agronomiques, faisabilité et durabilité à la ferme de la Noria

Plant-based extracts are biostimulants rich in active compounds and nutrients. Their aim is to stimulate crop growth, enhance tolerance to stress, and promote soil microbial communities. The effects of fermented extracts and Fermented Forest Litter (LiFoFer) on crops remain poorly studied and not fully characterized, although some trends have emerged in the literature. In the current context of reducing external inputs and enhancing agricultural sustainability, this study aimed to evaluate the effects of fermented biostimulants—nettle and comfrey fermented extracts, and LiFoFer—on the vigor of 40 young fruit tree rootstocks compared with 40 untreated controls, as well as their impacts on soil fertility at the base of the trees. Several growth variables were measured: main stem growth, trunk diameter increase over one year, secondary shoot biomass, leaf chlorophyll content, and root development. Soil variables included organic matter decomposition, microbial respiration, aggregate stability, residual nitrogen, and soil moisture. Results showed no significant effect of the biostimulants on either trees or soil, except for a single trend toward improved aggregate stability (+6%) in the 2–10 cm horizon. The experiment was limited by low statistical power and high variability among rootstock types. Multi-year observations would be necessary to detect potential effects on plant growth and soil properties, which evolve slowly. Nevertheless, these fermented preparations represent a valuable tool for enhancing farm autonomy and a major lever for improving system resilience. ; Les extraits à base de plantes sont des biostimulants riches en composés actifs et en nutriments. Ils visent à la fois à stimuler la croissance des cultures, à les protéger des stress et à stimuler les communautés microbiennes du sol. La Litière de Forêt Fermentée (aussi appelée LiFoFer) n’est pas légalement considérée comme un biostimulant mais est utilisée en tant que tel. Encore peu étudiés, les effets des extraits fermentés et de la LiFoFer sur ...