Zdzisław Ciećko

Effect of soil contamination with fluorine on the yield and content of nitrogen forms in the biomass of crops

The research was based on a pot experiment, in which the response of eight species of crops to soil contamination with fluorine was investigated. In parallel, some inactivating substances were tested in terms of their potential use for the neutralization of the harmful influence of fluorine on plants. The response of crops to soil contamination with fluorine was assessed according to the volume of biomass produced by aerial organs and roots as well as their content of N-total, N-protein, and N-NO3−. The following crops were tested: maize, yellow lupine, winter oilseed rape, spring triticale, narrow-leaf lupine, black radish, phacelia, and lucerne. In most cases, soil pollution with fluorine stimulated the volume of biomass produced by the plants. The exceptions included grain and straw of spring triticale, maize roots, and aerial parts of lucerne, where the volume of harvested biomass was smaller in treatments with fluorine-polluted soil. Among the eight plant species, lucerne was most sensitive to the pollution despite smaller doses of fluorine in treatments with this plant. The other species were more tolerant to elevated concentrations of fluorine in soil. In most of the tested plants, the analyzed organs contained more total nitrogen, especially aerial organs and roots of black radish, grain and straw of spring triticale, and aerial biomass of lucerne. A decrease in the total nitrogen content due to soil contamination with fluorine was detected only in the aerial mass of yellow lupine. With respect to protein nitrogen, its increase in response to fluorine as a soil pollutant was found in grain of spring triticale and roots of black radish, whereas the aerial biomass of winter oilseed rape contained less of this nutrient. Among the analyzed neutralizing substances, lime most effectively alleviated the negative effect of soil pollution with fluorine. The second most effective substance was loam, while charcoal was the least effective in this respect. Our results showed the effect of soil contamination with fluorine on the yield and chemical composition of fluorine depended on the species and organ of a tested plant, on the rate of the xenobotic element and on the substance added to soil in order to neutralize fluorine.

LONG-TIME EFFECT OF HARD COAL ASH ON THE CONTENT OF SOME ELEMENTS IN SOIL

The aim of the study was to determine the long-time effect of meliorating doses of hard coal ash (0, 100, 200, 400, 600 and 800 t · ha -1 ) on the content of some elements in soil with the application of different organic substances: manure, straw and bark. Nineteen years after the application of ash there was still an increase in the total content of all elements in soil. Its magnitude depended on soil horizon and it was highest in the humus horizon. The increase in the content of nutrients was, in general, proportional to the applied doses of ash. In the surface layer of soil, the increase was particularly high for sodium and subsequently for calcium, magnesium, sulphur, potassium and phosphorus, arranged in the order of decreasing values. The content of elements in deeper soil layers was significantly lower than in the 0–25 cm zone. A gradual reduction in the content, together with the increase in depth, was recorded only for magnesium and sulphur. The lowest concentration of phosphorus and calcium was detected in the 51–75 cm layer, while in the case of potassium it was in the 26–50 cm zone. The substances introduced into the soil in order to reduce the impact of ash generated by hard coal combustion did not exert any significant impact on the content of elements 19 years following their application.

Influence of Foliar Nitrogen and Magnesium Fertilization on Concentration of Ash Micronutrients in Potato Tubers

Abstract: The paper contains a discussion of the results of an experiment concerning the effect of foliar nitrogen and magnesium fertilization on the concentration of ash macronutrients in edible potato tubers of a medium-early cultivar called Zebra. The trials were based on a three-year, two-factorial field experiment, carried out in 2005–2007 at the Research Station in Tomaszkowo, owned by the University of Warmia and Mazury in Olsztyn. The applied fertilization consisted of 80 kgN, 35 kgP and 100 kgK ha. The first experimental factor comprised foliar nitrogen fertilization in the range of doses (8; 40) kgN ha accompanied by simultaneously diminished doses of soil nitrogen fertilization. The second factor included three series: without magnesium, with magnesium introduced to soil in a rate of 24 kg ha and with magnesium sprayed over potato leaves in a rate of 12 kgMg ha. Tuber samples were analyzed for the concentrations of phosphorus, potassium, magnesium and sodium. The content of these macronutrients tended to decrease under the influence of the increasing nitrogen fertilization, with the exception of phosphorus, whose concentration rose in the series unfertilized with magnesium under the effect of 8 and 16 kgN, and the concentration of sodium, which continued to increase in the Mg fertilized series up to the rate of 24 kg of N applied as a foliar fertilizer. The mean Ca : P = 0.28, Ca : Mg = 0.39 and K : Ca = 11.9 ratios suggest very poor calcium supply of the potato cultivar. In contrast, very broad ratios between K : (Ca + Mg) = 3.32 and K : Mg = 4.60 prove that the concentrations of potassium and magnesium were relatively high. The foliar application of nitrogen, tested in this experiment, had a significant effect on the ratios between ash elements in tubers. It has been demonstrated that as the top-dressing rate of nitrogen increased, the Ca : P and Ca : Mg ratios narrowed while the ratios of K : (Ca + Mg) and K : Ca were broader. The applied fertilization had no effect on the K : Mg ratio.

Long-Term Effect of Coal Fly Ash Application on Soil Total Nitrogen and Organic Carbon Concentrations

The study was performed on the basis of a field experiment established in 1984. Coal fly ash was applied at a rate of 0–800 t/ha with organic fertilizers — farmyard manure, straw, and tree bark. In the first years of research, only traditional crops were grown in trial plots. Since 1992, the field was used as permanent grassland, and no mineral amendments were applied. Nineteen years after fly ash application, soil samples were collected for analyses, which included determination of organic C and total N levels. It was found that coal fly ash applied in 1984 permanently changed the properties of the soil. Despite passage of a long period since their application, significant differences were still observed among the combinations, especially in the organic carbon content of the soil plough layer. The organic carbon concentration was also permanently affected by organic fertilizers. Tree bark had the most beneficial effect on the soil levels of organic carbon. The experimental factors had a less powerful influence on the total nitrogen concentration. The C:N ratio of the soil showed that coal fly ash considerably modified nitrogen values. This indicates a long-term effect of coal fly ash on nutrient immobilization and mineralization in the soil.