Exploring the responses of young vine (Vitis vinifera L.) plants to combined soil amendment with biochar and wood distillate

The increasing interest in bioproducts obtained from recycled plant biomass, in a perspective of climate change mitigation and food security, has prompted the investigation of the combined impact of biochar and wood distillate (WD) as soil amendments on plant performance. This study aimed to examine the effects of applying biochar and WD, alone and in combination, on the growth of young vine plants (Vitis vinifera L. var. Sangiovese). The experiment consisted of four treatments: 20% (w/w) biochar and 0.5% (v/v) WD in weekly fertigation, 20% (w/w) biochar, 0.5% (v/v) WD, and a control. Data showed that, regardless of the presence of biochar, WD fertigation led to a decrease in shoot biomass and an increase in root biomass, while biochar application positively affected root expansion and length. Although applying biochar and WD alone led to a decrease in shoot glucose content, their combination resulted in a glucose content like that of the control. WD increased the amino acid content, including phenylalanine and tyrosine, which are precursors of phenolic compounds. Biochar and WD, either alone or in combination, increased K content, while decreased that of Ca, Mg, and P in shoots and roots. However, WD promoted an increase in root P content. Although the Na content in the biochar-amended soil was high, plants primarily accumulated it in the roots, while the roots of WD amended plants showed even lower Na content than that of the control. Moreover, WD increased soil cation exchange capacity, regardless of biochar addition. Organic C content increased in both biochar- and WD-fertilized soil. In conclusion, this study underlined a synergistic effect of biochar and WD on plant physiology, especially in terms of root growth, indicating that the combined use of these bioproducts could be a potentially feasible and sustainable solution for enhancing crop performance.