Effect of Ash from Biomass Combustion on the Selected Elements Accumulation in Plants and Soil

Ashes from biomass combustion (BAs) are waste materials that contain valuable nutrients, making them suitable for reuse in plant fertilization. The application of ash positively impacts soil properties, including the reduction of excessive acidification, which enhances nutrient absorption. However, the use of ash can also introduce potentially toxic elements into the soil in excessive amounts. This study analyzed the effect of different doses of BAs on the accumulation of zinc (Zn), copper (Cu), nickel (Ni), chromium (Cr), lead (Pb), and cadmium (Cd) in the surface layer of Haplic Luvisol soil and in various parts of spring barley plants. The research was conducted over three years under field experiment conditions. Throughout the three-year study period, no significant changes were observed in the content of individual elements in the soil or in various parts of the spring barley plants. The analyzed elements tended to accumulate more in the roots of the plants than in their above-ground parts. When considering the average content of individual elements for the entire study period, no significant increase was noted in their levels within the analyzed soil. However, when examining each year of the experiment separately, significant dynamics in the content of individual elements in both plants and soil were identified. These fluctuations were likely influenced by variations in weather conditions, as the highest concentrations of the analyzed elements were typically recorded in the second year of the study, which coincided with the highest total rainfall of 792.4 mm. The findings indicate that analyzing changes in the content of elements introduced via biomass combustion ashes necessitates comprehensive studies conducted under both controlled and real- world conditions. Without such thorough investigations, conclusions regarding the release of components contained in BAs, particularly concerning their potential toxicity, may be misleading.