Common Ivy (Hedera helix L.) Derived Biochar’s Potential as a Substrate Amendment: Effects of Leached Nutrients on Arabidopsis thaliana Plant Development

Abstract

Common ivy, Hedera helix L., could be a potential feedstock for biochar production based on its physicochemical characterization. However, this has not been supported by plant-growth experiments yet. Therefore, this study aims to provide insight into possible correlations between common ivy biochar's physicochemical characteristics and plant development, for the first time. Lab-scale 96-well plant growth experiments were performed on Arabidopsis thaliana seedlings, using common-ivy based biochars produced at 400 and 700 °C and with and without valuable compound extraction before pyrolysis. Potassium leaching from the biochars caused the growth medium's pH and conductivity to increase significantly after 7 cultivation days. This leaching caused the plants to express initial growth stress responses (Pearson = 0.930), which was proven by changes in their cell cycle regulation. Further cultivation, 7-10 days, showed total recovery of the seedlings subjected to biochars produced at 400 °C. Moreover, significant increases in plant fresh weight were established at 1% biochar concentration. Besides that, biochars produced at 700 °C did not significantly affect plant development compared to the control group due to the decreased phosphate availability of the growth medium. In conclusion, low-temperature (400 °C) outperform high-temperature (700 °C) biochars, and valuable compound extraction before pyrolysis does not impact the biochar performance. Graphical Abstract Keywords Common ivy · Arabidopsis thaliana · Biochar · Plant growth · Nutrient leaching Statement of novelty This study provides novel insights into the correlation(s) between important biochar functional properties (leaching of nutrients, presence of PAHs, ...) and the growth of plants cultivated in a liquid medium. As such, both phenotypical properties (root length and plant fresh weight) and nuclear DNA contents (plant ploidy levels) were examined in great detail using state-of-the-art analysis methodologies. Additionally , for the first time, biochars produced from a promising new bioresource, common ivy., were tested as potential sustainable fertilizers. Furthermore, to add to the novelty of this study, valuable compound extractions of the biomass Extended author information available on the last page of the article