Levels of macro and trace elements in vegetable crops as influenced by metallurgical slag addition to marginal soil

Abstract

Through the vegetative experiments performed in semi-controlled conditions the influence of calcium containing metallurgical slag, a by-product from the Steel factory, as well as the effects of selected commercial lime materials and fertilizers, on macro (N, P, K, Ca, Mg) and trace elements (Fe, Zn, Cu, Cd) content in common spinach, cabbage and radicchio grown on Stagnosol (a soil with high acidity), was studied. P was determined by spectrophotometer, K-by flame emission photometry and N-using elemental CNS analyzer Vario EL III. In the determination of Ca, Mg, Fe, Zn, Cu and Cd, atomic absorption spectrometry was used. The results of the paper indicate that all lime materials studied, along with the studied metallurgical slag, showed positive effects on the content of main and beneficial biogenic macroelements in aboveground biomass of the tested vegetables. There is a noticeably tendency of a little increase in the content of P in all tested plants and Ca in spinach and cabbage in the treatment with mineral fertilizer, manure and metallurgical slag in relation to the control. Regarding the concentration of trace metals in tested vegetables, there was not found higher accumulation of Fe in tested plants in the treatments where metallurgical slag was applied in spite of its significant content in this liming material. As for Cd, its concentrations were within the safety limits and allowed concentrations in all the treatments, which is a highly desirable outcome.