Ivan Salamon

Composting of mixed medicinal plant waste was performed with the addition of mixture of plant growth promoting bacteria (PGPB), including Streptomyces sp., Paenybacillus sp., Bacillus sp., and Hymenobacter sp., and portions of spent coffee grounds (SCG). To assess the maturity and quality parameters of the compost, chemical and biological parameters (C/N ratio, loss of organic matter, CO2 production, dehydrogenase activity (DHA), and phytotoxicity) were evaluated during the three months of the composting process. The results revealed that the control sample (without the addition of SCG and PGPB) had evidently lower values of DHA during the entire monitoring period in comparison to other samples, indicating lower microbial activity in the compost mixture. Also, according to the released CO2, the composting process was accelerated in all samples where the SCG and PGPB were added, enabling a reduction in time needed for mixed plant waste to decompose. The germination index (GI) of the tested seeds indicated that the produced compost was acceptable and safe, with regard to all of the evaluated samples. However, at the end of the process the samples contained SCG and PGPB, which caused an increase of more than 50% of the GI in comparison to the control sample, expressing a high phyto-stimulant effect and improving the biofertilization impact.

The objective of this work was to map population of common juniper (Juniperus communis L.) in the territory of Slovak Republic. Common juniper is not protected by Slovakian law or the authorities; therefore, there is no law to preserve these plant populations. Biotopes of common juniper consist of light- to heavy-density trees and shrubs. The expansion of its habitat is also connected to human involvement. The loss of juniper naturally in observed plants is caused by a change in land use, loss of feeding pastures for cattle and sheep, and eutrophication of the environment. The current study was focused on monitoring the population of this plant species in the years of 2018–2020, the isolation of essential oils, and the identification of qualitative and quantitative characteristics. It was confirmed that juniper berries usually contain from 0.5 ± 0.05 to 1.8 ± 0.06%, usually 1.2 ± 0.16%, volatile oil depending on geography, altitude, ripeness, and other factors. Volatile oil is made up mostly of monoterpenes, mainly α-pinene (from 37.60 ± 2.23 to 61.00 ± 0.60%), β-myrcene (from 8.03 ± 2.02 to 10.56 ± 0.05%), and sabinene (from 3.50 ± 0.30 to 22.0 ± 0.96%). The dendrogram was constructed after a hierarchical cluster analysis based on the essential oil substances, which showed four different confirmed chemotypes. The essential oil is widely used in medicines, perfumes, insect repellents, insecticides, shoe polish, and in microscopy as a clearing agent of an immersion oil. The quality and chemotypes of juniper berries are very important for the Slovak national beverage “Borovicka” and the distillery industry on a whole in this country.