Comparison of the effect of liming and magnesium treatment of heavy metal contaminated soil on the content of magnesium, calcium and iron in broad beans (Vcia faba L. ssp. maior)

Abstract

Tests have been conducted to determine the effect of liming and magnesium treatment on the content of magnesium, calcium and iron in broad bean plants growing on soil polluted with such heavy metals as cadmium, lead, nickel, copper and zinc. In 2005, an experiment was conducted in the village Zagaje Stradowskie (OEwiêtokrzyskie Province) on degraded Chernozem formed from loess, acid in reaction and containing 1.13% of organic carbon. Analyses were performed on aerial parts of cv. White Windsor broad bean (Vicia faba L. ssp. maior), cultivated in three series: on limed soil, on soil receiving magnesium fertilizers; on unlimed soil without magnesium fertilization. In each series, the plants were cultivated on the following objects: unpolluted soil with a natural content of heavy metals (control); unpolluted soil with a natural content of heavy metals and mineral fertilization (control+NPK); soil polluted with a cadmium dose 4 mg⋅kg–1 d.m.; soil polluted with a dose of 530 mg⋅kg–1 of lead; soil contaminated with a copper dose 85 mg⋅kg–1 d.m., soil contaminated with a dose of 1000 mg⋅kg–1 of zinc and soil polluted with a nickel dose 110 mg⋅kg–1 d.m. Liming was based on the analysis of hydrolytic acidity of soils from individual objects. The administered dose was established according to 1Hh. Magnesium treatments were identical in all objects. i.e. 20.4 mg⋅kg–1 soil d.m. Soil contamination with zinc or nickel leads to a considerable decrease in magnesium and calcium level in broad bean aerial parts but rises iron level. Liming rather than ma gnesium fertilization applied to soil polluted with heavy metals, such as zinc or nickel, contributes to balancing the content of the analyzed macronutrients in broad beans. The content of Ca, Fe and Mg in plants after liming approached the level determined in the control plants.