The effect of fertilizing soils degraded by the metallurgical industry on the content of elements in Lactuca sativa L.

The aim of the study was to determine the content of macroelements (Ca, K, P, S, Mg) and microelements (Fe, Cr, Ni, Mn, Zn, Pb, Zn, Ti) in the leaves of Lactuca sativa grown in soils contaminated by the mining and metallurgical industry. The plants were cultivated using four fertilization variants: (a) unfertilized soil, (b) mix of straight fertilizers, (c) multinutrient fertilizer and (d) organic fertilizer, namely granular cattle manure. The study also involved an analysis of metal accumulation degree in the edible parts of lettuce by means of calculating a bioaccumulation index—transfer factor (TF). The analysis of the impact of fertilization on the content of the elements in the edible parts of fertilized versus unfertilized lettuce demonstrated that phytoavailability of the metals was most effectively limited by the multinutrient fertilizer and the mix of straight fertilizers. The organic fertilizer proved to be the least effective. The highest TF values (> 0.1) were recorded for macroelements, which denotes their intense and moderate accumulation. Poor bioaccumulation was observed for Cr, Mn, Ni and Zn (0.01 ≤ TF < 0.1), whereas in the case of Fe, Pb and Ti—trace bioaccumulation or no bioaccumulation was found (TF ≤ 0.01).