Winery Residues Transformed into Biochar and Co-Applied with Trichoderma Increase Grape Productivity and Soil Quality

The application of biochar is extensively recognized as an effective strategy to enhance soil ecosystem services. However, its combined effect with beneficial microorganisms, such as Trichoderma, still requires further investigation to understand its impact on soil microbiota and nutrient cycling processes. To address this gap, this study aimed to evaluate the effect of biochar produced from on-farm winery waste, specifically grape stalks (GSB) and grape fermentation residues (GFB), generated after wine production, when co-applied with Trichoderma aureoviride URM 5158 and Trichoderma hamatum URM 6656 in soil cultivated with Malbec grapevines. Our findings reveal that both types of biochar and Trichoderma promoted changes in soil properties. The application of GSB biochar combined with T. hamatum increased grape productivity, while GFB biochar enhanced soil enzymatic activities, particularly those expressed per unit of microbial biomass carbon. Additionally, biochar applications increased pH, phosphorus, potassium, organic carbon, and microbial biomass carbon of the soil. Soils treated with the GFB + T. hamatum treatment exhibited an increase of 569.23% in microbial biomass carbon compared to the control. The results of this study provide substantial evidence that biochar and Trichoderma can be used to improve the chemical and biological properties of vineyard soils, increasing nutrient availability, especially carbon. These effects may contribute to soil fertility by promoting a more favorable environment for microbiota development and grapevine growth. This is the first field study to investigate the impact of on-farm winery waste transformed into biochar, combined with Trichoderma isolates, on Malbec grapevines.