Macroelements and heavy metals content in energy crops cultivated on contaminated soil under different fertilization-case studies on autumn harvest

Heavy metals (HMs) contamination of soils is a major problem occurring worldwide. Utility of energy crops for biofuel feedstock production systems offers a feasible solution for a commercial exploitation of an arable land contaminated with HMs. Experiments involved field testing of Miscanthus x giganteus and Spartina pectinata cultivated on HMs-contaminated soil with standard NPK fertilizers and commercially available microbial inoculum. Biomass yield, water content, macronutrients (N, P, K, Mg, Ca), and heavy metal (Cd, Pb, Zn) concentrations in plant shoots were assessed at the end of the first and the second growing season. Independently of the applied fertilizers, Miscanthus x giganteus produced higher biomass yield while contrary results were obtained for S. pectinata. Higher HMs content in plants influenced the status of the mineral macronutrients in particular N and K. Occurrence of hasted senescence induced by drought in the second growing season caused reduction in the concentrations of all elements (except Pb), due to earlier rhizomes relocation.