The Bioavailability of Manganese in the Marigold (Calendula officinalis L.) Grown on Alkaline Soil

The research includes analysis of: pH value, organic matter content, and the total concentration of manganese in eleven soil samples from different localities northeast of Bosnia and Herzegovina. Sequential extractions of soil samples were also performed to determine the content of some form of binding manganese. Concentration of manganese in the flowers of calendula were also found and tested at these sites. From the obtained measurement, BCF (Bioconcentration Factor) values were calculated for the tested metal. Soil pH had values from 7.84 to 8.54, which puts them in the category of alkaline and strongly alkaline soil. The total concentration of manganese measured in soil samples do not exceed the limit values or are above average values. In the analyzed soil samples, the minimum content of manganese in the exchangeable fraction and the largest in the residual fraction and bound for oxides of manganese and iron. The concentrations of manganese in the flowers of calendula have not exceeded the permitted value. Statistical analysis of the results showed a weak linear correlation between pH value of an aqueous solution of the soil and the content of manganese in the flower, and linear correlation between manganese in the exchangeable fraction and the content of manganese in the flower. The calculated BCF values are very low and suggest that calendula growing on alkaline soil hasn’t got an expressed potential for accumulation of manganese.