Analysis of the effect of sandy soil amendment with biochar on its physical and chemical properties and the quantity and quality of biomass yield of energy crops

This study attempted to analyze the effect of biochar fertilization with the biomass of Virginia fan -petals (Sida hermaphrodita) on selected physical and chemical properties of sandy soil. The biomass yield of three energy crop species grown on such fertilized soil was evaluated. The content of heavy metals accumulated in the biomass of selected energy crops and the soil after crop cultivation was also determined. The examinations were carried out under conditions of the lysimeter experiment (natural conditions). Sandy soil was used for fertilization, with biochar doses of 0.5%, 1%, 1.5%, and 2% (by weight). The control material was non-fertilized soil. The study was carried out for 3 y. After each growing season, selected soil properties, the volume of biomass obtained, and the bioaccumulation of heavy metals were analyzed. Fertilization of the sandy soils with biochar caused a significant increase in the yield of all three energy crops studied, including Sida hermaphrodita. Of all the species cultivated, this plant responded best to biochar amendment. An optimum dose of this fertilizer was 1.5%, which, in the first year of cultivation, caused an increase in yield by 21.1% compared to control plants. The study showed that the use of biochar as a fertilizer did not cause an increase in contamination of the sandy soils with heavy metals. The application of biochar to sandy soil with all doses resulted in an improvement of selected sorption properties including a statistically significant increase in pH (active acidity), a decrease in hydrolytic acidity (potential acidity), an increase in the content of phosphorus, nitrogen, total carbon, and organic matter.