THE LONG-TERM IMPACT OF AMELIORATING DOSES OF HARD COAL FLY ASH ON SHAPING THE CONTENT OF SELECTED MICROELEMENTS IN AGRICULTURAL SOIL

The effect of ameliorating doses of hard coal fly ash (HCFA) on chemical properties of soil and on yields and chemical composition of crops was examined based on an experiment established in 1984. At first, typical agricultural crops were grown in the experiment, but in 1992 the field was turned into permanent grassland. The current study took place twenty-nine years after hard coal fly ash had been applied. Soil samples were collected from the 0–20 cm soil layer, corresponding to the compared treatments. The residual effect of HCFA doses increasing from 100 to 800 Mg·ha-1 caused a regular increase in the total content of Cd, Cr, Cu, Mn, Fe, Zn and Pb, as well as the forms of Zn, Cu, Mn, Fe and B soluble in 0.1 M HCl. The total content of the analyzed microelements increased by a maximum of 30% for cadmium up to 176% for zinc. The highest increase in the content of soluble forms ranged from 25% for Fe to 760% for boron. The share of Znbd, i.e. permanently bound to soil, to Zntot, i.e. the total zinc form, was positively correlated with pH in KCl, the C:N ratio and the content of Cu permanently bound with soil. Regarding the share of Febd in Fetot, correlations with pH in H2O and in KCl, content of organic matter (SOM) and the C:N ratio were demonstrated. No such correlations were proven with respect to the other elements. W doświadczeniu założonym w 1984 roku badano działanie melioracyjnych dawek popiołów ze spalania węgla kamiennego (hard coal fly ashes – HCFA) na właściwości fizykochemiczne gleby oraz na plonowanie i skład chemiczny roślin uprawnych. W pierwszych latach badań uprawiano typowe rośliny rolnicze, a w 1992 zmieniono charakter uprawy na trwały użytek zielony. Obecne badania wykonano po dwudziestu dziewięciu latach od zastosowania HCFA. Próbki gleby pobrano z poziomu 0–20 cm w nawiązaniu do porównywanych obiektów. Następcze działanie rosnących dawek HCFA od 100 do 800 Mg·ha-1 powodowało zarówno wyraźnie regularny wzrost zawartości całkowitej – Cd, Cr, Cu, Mn, Fe, Zn i Pb, jak i form rozpuszczalnych w 0.1 M HCl – Zn, Cu, Mn, Fe i B. Zawartość całkowita rozpatrywanych mikroskładników maksymalnie wzrosła o 30% w przypadku kadmu do 176 % w odniesieniu do cynku. Maksymalny wzrost zawartości form rozpuszczalnych kształtował się od 25 % w odniesieniu do żelaza do 760 % w przypadku boru. Udział Znbd tj. trwale związanego z glebą w stosunku do jego formy ogólnej Zntot, istotnie dodatnio korelował z pH w KCl i stosunek C:N oraz z Cu trwale związaną z glebą. W odniesieniu do udziału Febd w Fetot wykazano korelacje z pH w H2O, pH w KCl, SOM i C:N ratio. W odniesieniu do pozostałych badanych pierwiastków takich zależności nie wykazano

Mineral Neutralizers as a Tool for Improving the Properties of Soil Contaminated with Copper

In phytoremediation processes implemented in highly contaminated areas, there is a high risk of contaminant toxicity during the germination of freshly sown plants. In such conditions, it is recommended to support phytoremediation by using neutralizing additives. The present study aimed at assessing the effect of the addition of mineral neutralizers (MNs), i.e., limestone, clay, and zeolite, to soil contaminated with copper (0, 200, 400, 600 mg kg−1). Basic soil indicators were analyzed, such as pH, hydrolytic acidity (HAC), total exchangeable bases (TEB), cation exchange capacity (CEC), base saturation (BS), electrolytical conductivity (EC), total organic carbon (TOC), total nitrogen (Ntot), carbon to nitrogen ratio (C:N),, and interactions of soil micronutrients, such as Cu, Zn, Cd, Cr, Ni, Pb, Mn, and Fe with MNs. Copper contamination significantly decreased the soil pH and increased its HAC. A decrease in the share of TEB was found, which resulted in a decrease in the CEC and in BS of the soil. Among the additives, limestone had the most beneficial effect on reducing soil acidity, contributing to a significant increase in TEB, CEC, and BS. The least favorable effect was shown for clay, which generally caused the deterioration of soil properties. The MNs significantly increased the content of Zn, Cr, and Fe and lowered the content of Ni in the soil compared to the control. The demonstrated interactions indicate the diversified activity of MNs at different levels of soil contamination with copper

Mineral Neutralizers as a Tool for Improving the Properties of Soil Contaminated with Copper

In phytoremediation processes implemented in highly contaminated areas, there is a high risk of contaminant toxicity during the germination of freshly sown plants. In such conditions, it is recommended to support phytoremediation by using neutralizing additives. The present study aimed at assessing the effect of the addition of mineral neutralizers (MNs), i.e., limestone, clay, and zeolite, to soil contaminated with copper (0, 200, 400, 600 mg kg−1). Basic soil indicators were analyzed, such as pH, hydrolytic acidity (HAC), total exchangeable bases (TEB), cation exchange capacity (CEC), base saturation (BS), electrolytical conductivity (EC), total organic carbon (TOC), total nitrogen (Ntot), carbon to nitrogen ratio (C:N),, and interactions of soil micronutrients, such as Cu, Zn, Cd, Cr, Ni, Pb, Mn, and Fe with MNs. Copper contamination significantly decreased the soil pH and increased its HAC. A decrease in the share of TEB was found, which resulted in a decrease in the CEC and in BS of the soil. Among the additives, limestone had the most beneficial effect on reducing soil acidity, contributing to a significant increase in TEB, CEC, and BS. The least favorable effect was shown for clay, which generally caused the deterioration of soil properties. The MNs significantly increased the content of Zn, Cr, and Fe and lowered the content of Ni in the soil compared to the control. The demonstrated interactions indicate the diversified activity of MNs at different levels of soil contamination with copper

Content of phenolic compounds in soils originating from two long-term fertilization experiments

The objective of the study was to compare the impact of three systems of multiannual fertilization applied in two long-term field experiments on the content of phenolic compounds in the soil. In the study, both natural (manure, slurry) and mineral (NPK) fertilizers were used, along with combined, organic-and-mineral fertilization. Experiment I was established in 1972 on grey brown podzolic soil; experiment II, in 1973 on brown soil. In both experiments crops were cultivated in a 7-year rotation, with a 75% share of cereals. The experimental samples were taken from the top layer of soil after 36 (experiment I) and 35 (experiment II) years following the establishment of the experiments. It was demonstrated that the presence of phenolic compounds in the soils was significantly dependent on the contents of organic C and total N, type of soil and the type and dose of used fertilizers. In grey brown podzolic soil, the content of total phenolic compounds was at a lower level than the content found in brown soil. Multiannual fertilization contributed to an increase in the content of total phenolic compounds in relation to the values obtained in control objects, which was particularly reflected in the soil originating from objects fertilized with slurry applied at a dose being equivalent to manure in terms of the amount of introduced organic carbon. The percentage of water-soluble phenols in the total content of these compounds in grey brown podzolic soil was at the level of 18.4%, while in brown soil it amounted to 29.1%

Mineral Materials as a Neutralizing Agent Used on Soil Contaminated with Copper

The aim of the investigation was to evaluate the response of plants, using black mustard (Brassica nigra L. Koch) as a model plant, to soil contamination with copper (0, 200, 400, 600 mg Cu kg−1 of soil), and to determine the effectiveness of the Cu immobilization with mineral neutralizing materials, such as lime, clay and zeolite. The plant yield depended on soil contamination and mineral amendments. In the series without neutralizing materials, the level of 600 mg Cu kg−1 reduced the yield and increased leaf greenness. Lime alleviated the toxicity of Cu in objects with 200 mg Cu kg−1. Zeolite slightly mitigated the harmful effects of Cu at the level of 400 and 600 mg kg−1. Zeolite lowered the SPAD index. In the chemical composition of plants, the content of Cu, K, Mg, Na and Ca in plants increased to 400 mg Cu kg−1, while the content of P decreased to 600 mg Cu kg−1. Among the materials, lime reduced the Cu accumulation in plants the most, followed by clay. Cu narrowed the majority of ratios and widened the Ca:P and K:Ca ratios in plants. The applied mineral materials, except lime, did not significantly affect the formation of these indicators