Uticaj đubrenja, kalcifikacije i faze razvića biljnog pokrivača na floristički sastav, prinos i kvalitet biomase travnjaka tipa Danthonietum calycinae Zornić, Vladimir, 1985-, 37911911 Travnjaci predstavljaju najrasprostranjeniji vid biljnog pokrivača na svetu i zauzimaju oko 40% svetskog kopna. Za što bolje korišćenje ovih površina, neophodno je primenjivati određene agrotehničke mere, a pre svega adekvatno đubrenje i blagovremeno košenje. Istraživanja su vršena u Mitrovom Polju na biljnoj zajednici Danthonietum calycinae, na nadmorskoj visini 684 m. Cilj rada je bio utvrđivanje uticaja đubrenja, vremena košenja (početak metličenja i puno cvetanje dominantne vrste zajednice) i kalcizacije (1000 kg ha-1 kreča) na floristički sastav, prinos i kvalitet travnjaka tipa Danthonietum calycinae. Tokom istraživanja su primenjeni sledeći tretmani đubrenja: N0P60K60, N0P60K60+Klebsiella planticola, N0P60K60+Bacillus subtilis, N60P60K60, N120P60K60, N180P60K60. Primena đubriva i košenje na početku metličenja su povećali privrednu vrednost pokošene biomase. Na tretmanima sa mineralnim azotom uz dodatak fosfora i kalijuma je došlo do povećanja udela trava osrednjeg kvaliteta, dok je na tretmanima bez azota povećan udeo leguminoza. Upotrebom mineralnog azota (pri konstantnoj količini fosfora i kalijuma) i kasnijim košenjem, povećan je prinos u svim godinama istraživanja. Najveći prinos postignut je na tretmanima N180P60K60, posebno u drugoj godini (9,50 t ha-1). Povećanje količine primenjenog azota sa 120 kg ha-1 na 180 kg ha-1 nije dalo adekvatno povećanje prinosa, pa se može zaključiti da upotreba viših količina azota nije ekonomski opravdana. Biomasa košena na početku metličenja sadržala je značajno više proteina u odnosu na biomasu košenu u fazi punog cvetanja. Sadržaj proteina u biomasi na tretmanima sa azotom je povećan odmah u prvoj godini, dok je na tretmanima bez azota neophodno bilo tri godine dok dominaciju preuzmu leguminoze. Najveći prinos proteina po jedinici površine je dobijen na tretmanima N180P60K60, u drugoj godini istraživanja (968 kg ha-1). Na ranije košenim tretmanima je dominirao neproteinski azot, dok je na kasnije košenim tretmanima ustanovljena veća koncentracija nerazgradive frakcije proteina. Brojnost generativnih izdanaka travnih vrsta značajno je stimulisana kasnijim košenjem i dodavanjem azota. Primena đubriva i kalcizacija je imala pozitivno delovanje na brojnost mikroorganizama zemljišta, osim na tretmanima N180. Dobijeni rezultati ukazuju da se optimalni i ekonomski isplativi rezultati sa aspekta prinosa i kvaliteta biomase, kao i očuvanja mikrobiološke aktivnosti zemljišta i životne okoline, dobijaju na tretmanima N120P60K60 i kosidbom na početku metličenja. Grasslands are the most widespread vegetation type worldwide, covering about 40% of the world's land. Management primarily proper fertilisation and timely mowing are required to ensure the best possible use of these areas. The research on the Danthonietum calycinae association was conducted at Mitrovo Polje, at an altitude of 684 m, on a ranker soil formed on serpentine rocks. The objective of this research was to determine the effect of fertilisation, mowing date (beginning of heading and full flowering of the dominant species) and liming (1000 kg ha-1 lime) on the floristic composition, yield and quality of Danthonietum calycinaе grassland biomass. The fertilisation treatments used in the study included N0P60K60, N0P60K60+Klebsiella planticolа, N0P60K60+Bacillus subtilis, N60P60K60, N120P60K60 and N180P60K60. Fertilisation and mowing at the beginning of heading increased the economic value of the harvested biomass. Treatments with mineral nitrogen, phosphorus and potassium led to an increase of the medium-quality grasses, while the treatments without nitrogen increased proportion of legumes. Application of mineral nitrogen and late mowing promoted biomass yield in all years of the research. The highest yield was achieved in N180P60K60 treatments, especially in the second year (9.50 t ha-1). Application of nitrogen rate, from 120 kg ha-1 to 180 kg ha-1 was not appropriate increase dry matter yield, so using higher rate of nitrogen is not profitable. The biomass mowed at the beginning of heading contained significantly more protein than the biomass mowed at full flowering. Protein content in the biomass under nitrogen treatment increased as early as the first year, whereas on treatment without nitrogen, protein content increasing was achieved in third year of experiment. The highest protein yield per unit area was obtained in N180P60K60 treatment in the second year (968 kg ha-1), when the highest amount of precipitation was recorded. Plots mown at the earlier date were dominated by nonprotein nitrogen, whereas those mown at the later date had a higher concentration of the undegradable protein fraction. Number of generative tillers of grass species was significantly stimulated by late mowing and increasing of nitrogen fertilisation. Fertilisation and liming promoted the soil microbial count, except under N180 treatment. The research results suggest that the high, optimal and profitable dry matter yield and biomass quality, as preserving soil fertility and the environment, was achieved under N120P60K60 treatment and mowing during early heading. Stevović, Vladeta, 1966-, 13597031 Simić, Aleksandar, 1970-, 12808295 Lugić, Zoran, 1963-, 5404775 Mandić, Leka, 1964-, 13598055 Babić, Snežana, 1977-, 37911399 Tomić, Dalibor, 1984-, 15002471 2019 2019 2019 2019 2019 2019 2019 2019 baccalaureate Dissertation 151 list 5070454 bytes o:1267 ID=19911177 ; D-3355 thesis:7554 cobiss:19911177 https://phaidrakg.kg.ac.rs/o:1267 Thesis:7554 Cobiss:19911177 srp CC BY 2.0 AT http://creativecommons.org/licenses/by/2.0/at/