Bioaccumulation of macronutrients in herbaceous plants of the Sławno glaciolacustrine plain, northern Poland

The studies aimed to compare bioaccumulation and translocation of macronutrients from roots to above-ground organs for six species of herbaceous plants (Taraxacum officinale, Rumex acetosa L., Plantago major L., Plantago lanceolata, Potentilla anserina L. and Hypericum perforatum L.) growing in the area of the Sławno Plain, northern Poland. Soil and plant samples were collected in June 2015 from 30 locations (five replications per species) and analysed using standard procedures, including content of nitrogen, phosphorus, potassium, calcium and magnesium. Mean contents of elements in the soil, roots and above-ground organs were calculated based on the results obtained. The content of organic carbon and pH were additionally determined in soil samples. The studied soils have been developed from silty-clayey glaciolacustrine deposits. They were characterised by acid and strongly acid reaction and contained from 9.5 to 28.7 g kg-1 of organic carbon. They were relatively abundant in nitrogen (1.44-1.87 g kg-1) and potassium (4.30-5.34 g kg-1), whereas poor in phosphorus (0.41-0.57 g kg-1), calcium (1.63-2.84 g kg-1) and magnesium (3.21-4.08 g kg-1). The content of these elements in roots and above-ground parts of the studied plants was usually higher as compared to the soil. It was typical for herbs, reflecting their physiological demands. Only K occurred in higher amounts. The observed contents of nutrients suggest sufficient supply. The lowest bioaccumulation factors in roots were noticed for Hypericum perforatum L. (for N, P, Ca and Mg) or Rumex acetosa L. (for K) and the highest for Plantago major L. (for N, P, K and Ca) or Rumex acetosa L. (for Ca). In above-ground organs weakest bioaccumulation occurred in Hypericum perforatum L. (for K, Ca and Mg), Rumex acetosa L. (for P) or Potentilla anserina L. (for N) and the strongest in Plantago major L. (for N and Ca), Taraxacum officinale (for K and Mg) or Plantago lanceolate (for P). The values of translocation factors from roots to above-ground organs ranged from 1.3 to 3.1 for nitrogen, from 0.8 to 2.0 for phosphorus, from 1.3 to 3.3 for potassium, from 1.1 to 3.7 for calcium and from 1.1 to 3.1 for magnesium. Potassium and calcium were strongly translocated in Taraxacum officinale, whereas nitrogen, phosphorus and magnesium in Hypericum perforatum L.