TOMAŠKIN JÁN, JANČOVIČ JÁN, VOZÁR ĽUBOŠ, TOMAŠKINOVÁ JUDITA: The eff ect of mineral fertilization on belowground plant biomass of grassland ecosystems. Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, 2013, LXI, No. 5, pp. 1431-1440 Aim of the work was to determine the eff ect of diff erent doses of mineral fertilization on belowground and aboveground plant biomass production of three diff erent types of grasslands, to state R:S ratio (root:shoot) and turnover period of belowground plant biomass of grasslands. In the contribution, we assess production of underground biomass, tillering zone and aboveground biomass on three types of grasslands -permanent grassland (PG), over-sown grassland (OSG) and temporary grassland (TG) in sub-mountain area of central Slovakia. There were applied four levels of mineral nutrition in each grassland (non-fertilized variant, var. 30 kg.ha −1 P and 60 kg.ha −1 K. var. 90 kg.ha −1 N + P 30 K 60 , var. 180 kg.ha −1 N + P 30 K 60 ). The root biomass has the most signifi cant share in the total biomass of grasslands (49.9-54.2 %), followed by tillering zone (33.3-36.0 %) and with the lowest share of aboveground biomass (11.9-16.8 %). A dominant share of root biomass and tillering zone ensure signifi cant extraproductive functions of grasslands that contribute to the stability of agriculture landscape. We recorded the lowest amounts of root mass on TG (7.31 t.ha ). The specifi c nitrogen stimulating infl uence on root biomass production has been proven. Production of tillering zone was lower on OSG and TG (5.11 or 5.42 t.ha −1 ), signifi cantly higher on PG (5.72 t.ha −1 ). We observed a signifi cantly higher production of tillering zone with variants which were fertilized with nitrogen than on non-fertilized and PK fertilized. The lowest harvests of aboveground biomass were noticed on TG (5.80 t.ha −1 ), signifi cantly higher on PG and OSG (6.35 or 6.54 t.ha −1 ). Mineral nutrition had a signifi cant impact on production of aboveground biomass. R:S ratio of the assessed grasslands achieved the values from 4.02 to 5.16. Higher values on PG (5.16) are indicating its higher resistance to drought. Turnover time of root biomass was the longest on PG 3.5-5.0 years, on OSG and TG 2.5-3.5 years. Based on achieved results, we recommend using the fodder plants cultivation system on PG or OSG. Permanent grasslands are proved as ecologically more stable and more resistant to drought than temporary grasslands; they can together with optimal mineral nutrition provide adequate production of root biomass (8.5 t.ha −1 ) and a harvest of aboveground biomass (6.3 t.ha −1 ). aboveground biomass, grass sod, grassland, plant biomass, root, R:S ratio, tillering zone, turnover time of root biomass Grass ecosystems are providing besides a productive function also signifi cant extraproductive functions (erosion control, retention, biofi ltration, environmental). Grass sod (root biomass and tillering zone) provides these functions and makes a dominant 80-85 % share in total product...

The aim of the research is to determine the effect of application of the developed product (extract) called ALGEX r 6 from natural mineral rock alginite in two different watering periods on the formation of root biomass and aboveground plant biomass of a selected group of medicinal plants (Melissa officinalis L., Malva verticillata L. and Ocimum × citriodorum Vis.) and determining the antioxidant activity in dried leaves and whole plants in aqueous and methyl alcohol extracts by DPPH method. The experiment was established in the Botanical Garden at the Slovak University of Agriculture in Nitra throughout 2020. ALGEX r 6 was prepared by a research team at the Slovak University of Agriculture in Nitra in the form of an extract from the natural mineral rock alginite with an application of thermal and chemical treatment. In the experiment, ALGEX r 6 was applied in the form of a watering in two variants with the same concentration of 3 % solution in 2 decilitres of water, but various application in terms of days in the pre-harvest stage of the above-ground plant biomass of 30 individual plants from each species. There are two diametrically opposite trends of ALGEX r 6 application that are manifesting themselves in M. officinalis and M. verticillata by reducing the root and above-ground part biomass compared to the control variant. The percentage proportionality of root/ above-ground part biomass in M. officinalis decreased from 62.48/30.31 % (control), to 45.57/18.85 % (variant 1) and to 36.07/17.27 % (variant 2), as well as in M. verticillata the root/above-ground part biomass decreased from 16.03/13.93 % (control), to 14.97/9.42 % (variant 1) and to 11.61/10.14 % (variant 2). In the species Ocimum × citriodorum Vis. the opposite trend manifested. The application of ALGEX r 6 watering resulted in increasing the antioxidant activity on the tested plant parts, especially in aqueous extracts in M. officinalis (from 19.30/control to 33.61 %/variant 1, 2), also in O. citriodorum (from 26.56/control to 44.16 %/variant 1), while in methyl alcohol extracts, the antioxidant activity showed a slight increase in all tested species.

The publication aims to present some knowledge about the less-known but at the same time very scarce bituminous rock alginite with comprehensive practical use in the form of a brief overview. Alginite is an organic-bituminous rock that was formed about six million years ago from dead fossil algae Botryococcus braunii Kütz and diatoms in the area of today's Pannonian Basin. In Europe, alginite deposits have been discovered in Hungary, Austria and Slovakia in Pinciná village. Alginite mining is mostly used in Hungary in the Gerce area. Alginite is grey to dark grey, in the wet state dark laminated, clayey with the form of disintegrating clay. Alginite has very valuable physical, mechanical and chemical properties. It is a natural bituminous rock with a favourable content of basic nutrients (P, K, Ca, Mg and S) for plants except for nitrogen content. Alginite contains a large number of microelements, which increase the agrochemical possibilities of its use. It can be applied in its natural form without chemical treatment. It is an ecological raw material that improves the soil and does not negatively affec the environment. Alginite has become the subject of research in many workplaces. The overview presents the basic physical, mechanical and chemical properties of alginite and selected knowledge and research results that have enabled the practical use of alginite in natural or technologically modified form in agriculture in the formation of growth, development and crop formation and quality of seeds and fruits of cultivated crops, forestry, remediation and improvement of soil and water properties, decomposition of herbicides, stabilization of beneficial microorganisms in animal organisms and other areas.

KOVÁR, P., VOZÁR, Ľ., JANČOVIČ, J.: The turfs quality of selected Slovak varieties of the genus Festuca under the conditions without irrigation. Acta univ. agric. et silvic. Mendel. Brun., 2012, LX, No. 6, pp. 181-188

KOVÁR PETER, VOZÁR ĽUBOŠ, JANČOVIČ JÁN:The infl uence of water extracts of selected turfgrass species on germination and initial growth of Poa annua L. Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, 2013, LXI, No. 3, pp. 677-681 The eff ect of Lolium perenne L., Festuca rubra L., Festuca arundinacea Schreb., Poa pratensis L. and Poa annua L. aqueous extracts on germination rate and total germinability of Poa annua L. seeds and length of Poa annua L. leaves and roots was studied in a laboratory experiment. Germination of seeds was conducted in the growth chamber at the light and temperature regime -day/night -12/12 hours, 23/15˚C, rh 70 %, for 42 days. Extracts signifi cantly aff ected the total germinability and germination rate of Poa annua L. seeds (p = 0.000). The lowest germinability (27.3 ± 7. 1 %) and germination rate (0.7 ± 0.2 seeds per day) had Poa annua L. seeds germinated in Poa pratensis L. aqueous extract. Used extracts (except for Festuca rubra L. extract) had signifi cantly inhibitory eff ect on length of Poa annua L.

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From the experimental study of fertilization renovation (a�er its three-year absence) on production capacity of seminatural grassland in the area of Strážov Hills (Middle Slovakia, height above see level 640 m, association Lolio-Cynosuretum Tx. 1937Tx. , time of experiment 1997Tx. -1999 it follows that yearly application of doses 60-120 kg N(+PK)/ha leads to a rapid renovation of production feat at high yield stability and production effects by infused nutriens (increase of yield 15.3 or 13.6 kg dry ma�er/kg NPK, 23.1 or 19.1 kg dry ma�er/kg N). Within the dose interval 120-240 kg N(+PK)/ha, the values of average production 1 kg N (8.64 kg dry ma�er) fall to almost one half in comparison to the interval 60-120 kg N(+PK)/ha, and when compared to the dose interval 0-60 kg N(+PK)/ha, they fall to almost one third. When alternating applications of nutrients in particular years (PK-NPK-PK, PK-0-PK, N 60 PK-N 120 PK-N 240 PK) the yield variation in time (V x = 25.56-43.64%) increases enormously in comparison to habitual application of the same nutrient doses (V x = 5.26-10.42%).

The botanical composition of 2 turfgrass mixtures on the basis of drought-tolerant species Festuca rubra L. and Festuca arundinacea Schreb. was evaluated by method of reduced projective dominance in natural conditions in the Research state Nitra (western Slovakia) during years 2007 -2012. The species composition of mixture was significant in the early stages of turf development. The rapidly evolving Lolium perenne L. (part of the mixture 1) had shortly after sowing relatively high ground cover. It was the dominant species in turf in year of turf establishment. Lolium perenne's part was successively decreased in next period. Festuca rubra agg. acquired the dominance in turf. Turfgrass mixtures, which contained slower evolving Festuca arundinacea Schreb. and very slowly evolving Poa pratensis L., had suitable ground cover in autumn in year of sowing or until spring in next year. The effect of supplied nutrients was reflected in year of sowing in mixture 1, resp. from the second year of cultivation in mixture 2, when the variants fertilized by a dose of 90 kg*ha -1 N (V3) exhibited higher ground cover of grasses compared to unfertilized variant (V1) and variant V2 (45 kg*ha -1 N). Higher dose of nitrogen (V3) promote the competitive strength of both mixtures, which resulted in low to very low occurrence of weeds in turf in comparison with other variants.