Deciphering the Effectiveness of Humic Substances and Biochar Modified Digestates on Soil Quality and Plant Biomass Accumulation

The effective use of digestate as exogenous organic matter to enhance soil carbon sequestration depends on the balance between labile and recalcitrant carbon, which is influenced by type feedstock, fermentation process, fraction (liquid, solid) fermented product used. In this work, in order change ratio stable resulting fertiliser, was mixed with carbon-rich supplements: biochar Humac (a humic acid-rich substance). pot experiment carried out under controlled conditions maize (Zea mays L.) amended (D), incubated (H), (B), or a combination both (D + B H) before application. Digestate enriched showed improved short-term nutrient (carbon, phosphorus, nitrogen) transformation, indicated enzyme activity highest biomass production of. Total content, C:N ratio, respiration activity, nitrification were most enhanced either combined Humac). Long-term nitrogen mineralization mostly Humac, amino-acid-induced urease activity. Short-term positive effects (eventually Humac) catabolism proven, whereas their long-term negative (i.e., biochar-mediated immobilization, sequestration), should be focus further research future.