## 3 Results and Discussion
They attempted to estimate the uptake and accumulation of selected nutrients and heavy metals by _Solanum nigrum_ grown on different types of soil. The results of their research showed that the highest content of sodium was found in plants grown on loamy soil. Regarding sulphur, its plant content in the series with loam tended to be approximately the same as its concentrations in the series without fluorine pollution. Loam is rich in humic acids. Humic acids can reduce the sulphur content in plants, e.g., in the aerial parts of maize [46]. In the research of other authors [42], lime application causeda reduction in sodium content in the grain and straw of oats, while loam had such an effect only in the straw of oats. The opposite impact was obtained in the straw of this plant. The lime application to soil leads to an ion exchange with sodium in a sorption complex. High sodium content in a soil solution may cause an increase in the sodium content in the organs of some plant species [47]. PCA analyses indicated that the total parameters describing the sodium content in the aerial parts of plants accounted for 70.84% (Figure 1), the sodium content in the plant species' roots was 82.06% (Figure 2), and the sulphur content in spring triticale seeds and parts of other plant species was 64.01% (Figure 3) of the correlation of the dataset. Vectors of sodium content in the aerial parts of most plant species were of similar length, which indicates a similar range of impact. The sodium content in the aerial parts of black radish and narrow-leaf lupine showed the highest correlation, and in yellow lupine and winter oilseed rape, a smaller negative degree of correlation with the dose of fluorine was observed. In the case of spring triticale, positive correlations were found. Negative correlations were also found between the sodium content in winter oil-seed rape and narrow-leaf lupine (as opposed to phacelia) and the application of neutralizing substances. In the case of phacelia, positive correlations were found. The sodium content in the roots of all plant species (except spring triticale), and especially in phacelia and narrow-leaf lupine, was negatively correlated with soil contamination with fluorine. Negative correlations between the sodium content and the application of neutralizing substances were found in yellow lupine and winter oilseed rape. Correlations between the sulphur content in plants and the studied parameters were relatively weak. However, the sodium content showed a negative correlation in yellow lupine and a positive correlation in spring triticale (weaker in narrow-leaf lupine) with the dose of fluorine. Negative correlations also occurred between the sulphur content in winter triticale and narrow-leaf lupine and the application of neutralizing substances. The sulphur content in phacelia and yellow lupine was positively correlated with these substances. Figure 1: Sodium content in aerial parts of plant species calculated with PCA method. Vectors represent sodium content in aerial parts of plant species versus fluorine dose and neutralizing substances application. phosphorus content in both aerial parts and plant roots, e.g., spring barley, oat, and white mustard [42; 48], and weaker negative correlations between potassium and sodium [48]. The study presented in this paper verifies that the impact of fluorine soil pollution on the plant content of macronutrients depends on many factors, of which the most important ones are plant species and soil conditions. When planning the remediation of soil polluted with this xenobiotic, both these factors should be given careful consideration.