Abstract
Thermal biomass transformation products are considered to be one of the best materials for improving soil properties. The aim of the study was to assess the effect of charcoal after cavitation on the chemical and biochemical properties of soil. The study was carried out with a 10% aqueous charcoal mixture that was introduced into loamy sand and clay at rates of 1.76%, 3.5%, 7.0%, and 14.0%. The effect of the application of cavitated charcoal was tested on Sorghum saccharatum (L.). Soil and plant material was collected to determine chemical and biochemical properties. The application of cavitated charcoal reduced the acidification of both soils. The highest rate (14.0%) of cavitated charcoal increased the content of soil total carbon (C(Tot)) by 197% in the loamy sand compared to C(Tot) in the control treatments, 19% for clay soil, respectively. The application of cavitated charcoal did not significantly change the total content of heavy metals. Regardless of the element and the soil used, the application of cavitated charcoal reduced the content of the CaCl(2)-extracted forms of heavy metals. Following the application of cavitated charcoal, the loamy sand soil presented an even lower content of the most mobile forms of the studied elements. It should also be noted that regardless of the soil texture, mobile forms of the elements decreased with the increased cavitated charcoal rate. The results of dehydrogenase and urease activity indicated the low metabolic activity of the microbial population in the soils, especially with the relatively high rates (7.0% and 14.0%) of cavitated charcoal. However, the cavitated charcoal used in the study showed a significant, positive effect on the amount of biomass S. saccharatum (L.), and its application significantly reduced the heavy metal content in the biomass of S. saccharatum (L.).