The study took place between 2012 and 2014 in Falenty near Warsaw, Poland, as part of a long-term scientific experi-ment (first began in 1987) using the randomized block method. All blocks were irrigated until 2008. In 2009 each block was divided into two areas: irrigated and non-irrigated. The study involved four levels of inorganic nitrogen fertilizer and two levels of mixed inorganic and organic fertilizer in the form of fermented cattle urine. The soil in all experimental plots was characterized by low levels of zinc, ranging from 7.6 to 16.7 mg Zn∙kg–1 dry matter. Much lower Zn content in both soil layers of all irrigated plots was associated with increased yields on these plots, regardless of the level and form of ferti-lizer. The content of Zn in soil and sward in 2014 year was significantly lower compared in 2012. Inadequate levels of zinc for ruminant nutrition were observed in the sward from all plots (15.4–28.8 mg∙kg–1 dry matter). The higher content of zinc was found in sward harvested from the plot, which was not fertilized with phosphorus. The long-term inorganic and fer-mented urine fertilization resulted in very low zinc content in the soil and meadow sward.
Bacteria from the Simkaniaceae family are intracellular parasites belonging to the Chlamydiales order, detected in surface waters, drinking water, chlorine water, and in wastewater. Its main representative, Simkania negevensis, is pathogenic to humans and animals, especially fishes, as it principally causes respiratory tract diseases. Bacteria from this family are also capable of surviving and existing in free-living amoebas, omnipresent in the natural environment, which makes them an additional risk for human and animal health. The aim of the present study was to search for representatives of this family in freshwaters from the Odra River and two municipal lakes (Rusałka and Goplana). Out of 100 water samples analysed, the sequence of bacteria of Simkaniaceae family was found just in 1 percent, because phylogenetic analysis revealed that the obtained OdraWCh30 sequence shows 93% similarity to Simkania negevensis strain Z as well as 87% similarity to Candidatus Syngnamydia salmonis isolate Ho-2008 and Candidatus Syngnamydia salmonis isolate VS10102006 and 84-85% similarity to endosymbiont of Xenoturbella westbladi, Simkaniaceae bacterium clone SM081012-5s and Candidatus Syngnamydia venezia strain Pi3-2. This is the first case of detecting sequence of bacteria of Simkaniaceae family in the aquatic environment in Poland.