Trichoderma activated granulated digestate as an alternative to chemical fertilization, effects on tomato yield and quality, and soil rhizospheric communities.

The use of synthetic fertilizers is always more economically and environmentally unsustainable. It is therefore necessary to improve current agricultural practices. Bioactivated fertilizers are a promising solution to enhance digestates solid fraction fertilizing properties with an ad hoc microbial consortium and reach yields comparable to chemical fertilization therefore combining circular economy with an upgraded organic agriculture. This study designed a new granulated formulation, obtained using a vacuum drying process at industrial level, for an improved Trichoderma activated digestate solid fraction. This granulation aimed to improve both management operations and Trichoderma activity. After a greenhouse experimentation, yield obtained from the activated digestate were similar to the one obtained with chemical fertilization. Microbial activation further led to higher nutritional values with an increment in lycopene content. A metagenomic analysis further highlighted the persistence of Trichoderma in tomato rhizosphere and its ability to establish positive interactions with other beneficial rhizospheric microorganisms. Activated digestate showed its potential to substitute chemical fertilisation while granulation resulted a functional formulation to convey this product.