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The paper presents an analysis of the trophic status of two small retention reservoirs located in the Subcarpathian region: Blizne reservoir on the River Ladzierz and Cierpisz reservoir on the River Tuszymka. The capacity of the reservoirs is respectively 137,000 m3 and 22,000 m3 and they occupy an area of 11.46 and 2.3 hectares. The study was conducted from May to October in 2013 and in 2014. Samples of surface water were collected from two locations for each reservoir. Assessment of the trophic status of the reservoirs was based on the concentrations of phosphorus, nitrogen and chlorophyll a. Criteria available in the literature were used to assess the trophic status. The progress of eutrophication was also evaluated on the basis of the Trophic State Index (TSI). Analysis of the results showed that in the studied period the water of Blizne was on the border of eutrophic and hypertrophic. The fertility of the water of Cierpisz in the analysed period deteriorated from the eutrophic state to the border with hypertrophic

The Alyssum genus, with its many metal-adapted species, is a good candidate for research on phytoremediation and metal tolerance mechanisms. These goals can be supported by elaborating on an in vitro multiplication protocol. Our study aimed to determine the aseptic conditions for the growth and effective propagation of Alyssum murale, A. alyssoides, and A. montanum, each exhibiting different adaptation strategies to nickel ions. Firstly, hydrogen peroxide (H2O2) or sodium nitroprusside (SNP) were investigated in the biological Lepidium test to find their optimal concentrations that could improve the germination attributes of tested Alyssum species. The concentration of 0.5 mM H2O2 or SNP was selected for research on Alyssum seeds, which were the initial material to start in vitro cultivation. Regardless of the species, H2O2 harmed germination percentage; however, its application accelerated radicle emergence, especially in metal-sensitive genotypes, while in both metal-tolerant ones, the germination time of H2O2-treated seeds was similar to that of treated with SNP. These findings provide a novel insight into the effect of H2O2 or SNP on seeds, contributing to a better understanding of their role in the germination of different genotypes. Among tested media compositions, the synchronous plant regeneration of all species was achieved on MS medium supplemented with 0.5 mg/L 2iP and 0.1 mg/L IAA, making an essential advancement in the in vitro protocols for metallophytes.

The work detailed in this study utilized 20 kHz ultrasonic irradiation as a mechanism of hydrogen peroxide production. The effects of various operating parameters were investigated, including ultrasonic intensity; solution pH; source of water; initial dibutyl phthalate concentration and the presence of hydrogen peroxide. During the irradiation, the H2O2 concentration was monitored. The results indicate that H2O2 is produced by cavitation during ultrasonic irradiation. An increase in ultrasonic intensity increases the amount of hydrogen peroxide produced. The initial pH of the solution does not affect the efficiency of processes substantially. H2O2 is regarded as one of the most effective additives enhancing the sonochemical production of hydroxyl radicals and hydrogen peroxide. Above a 0.1 mM dose of H2O2, the amount of H2O2 formed decreased as the concentration of H2O2 increased. Thus, the concentration of hydrogen peroxide plays a crucial role in the extent to which the effectiveness of the combined process is enhanced. The negative effect on reactions of the presence of additional components in the reaction solution was also confirmed. It was therefore concluded that the experimental evaluation of optimum parameters of hybrid processes is a matter of importance.

The aim of the study was to compare sulfate fertilizers and mixtures of elemental sulfur (S0) and sulfate in terms of yield and nitrogen (N) and sulfur (S) status in perennial ryegrass. Mixtures of sulfate and S0 can reduce the consumption of sulfate alone. The plants were grown in soil cultures. The plants were supplemented with S0, K2SO4, MgSO4, and (NH4)SO4 or a mixture of these salts with So. Two sulfur doses were applied and the ryegrass was harvested three times. Fresh and dry weights of each swath, the N and S content, and their uptake were determined. The total fresh yield of sulfur-fertilized plants was 25 to 94% higher compared to unfertilized plants. The increases in dry matter were even more significant. Fertilizers, being a mixture of S0 and sulfate, showed the same efficiency as those containing sulfate alone. Sulfur fertilization resulted in a higher S content and its uptake, lowered N concentration in second and third swatch, and a decrease in total N uptake. In conclusion, to achieve high crop yields, soil sulfur deficiency should be corrected and fertilizers that are the mixture of elemental sulfur and sulfate are a beneficial and effective approach.