Mineral Fertilization with UAN on Natural Grassland Festuca rubra L. with Agrostis capillaries L. Ioan ROTAR, Mirela CIREBEA*, Roxana VIDICAN, Florin PĂCURAR, Anamaria MALINAŞ, Ovidiu RANTA Faculty of Agriculture. University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, Manăștur Street, 3-5, 400372, Romania. * corresponding author: cirebea_mirela@yahoo.com Bulletin UASVM series Agriculture 73(2)/2016 Print ISSN 1843-5246; Electronic ISSN 1843-5386 DOI 10.15835/buasvmcn-agr: 12449 Abstract An important part of efficient livestock production is ensuring the sufficient grass for hay and pasture. However, low soil nutrient levels often limit forage production. With good fertilizer management and soil fertility, the productivity of many hay and pasture fields can be greatly improved. Through good fertilizer management, the productivity of many hay and pasture fields can be significantly improved by Ross H. McKenzie (2005). The aim of this paper was the effect of fertilization with liquid fertilizer (UAN) the harvest of dry and floristic composition changing on natural grassland. The experiment whose results we present was placed in 2014 in the place in Baisoara Mountain village, Cluj County. Experience has been placed on the Festuca rubra and Agrostis capillaries - of grassland type. The natural grassland of Festuca rubra with Agrostis capillaries responded very well to mineral fertilizers with liquid fertilizer UAN. The floristic composition of natural grassland fertilized with liquid fertilizers based on nitrogen, it can be seen an increase the Gramineae families and an evidence downward trend from Fabaceae families. Keywords: fertilization, liquid fertilizer, grassland. INTRODUCTION Most pastures are artificial products of people and animals. Realizing an optimum balance pasture and livestock ensures the maintenance and improv- ing permanent vegetation cover. Only by control- ling the mutual interaction between the two factors - plant and animal – we can obtain positive econom- ic results (Rotar and Carlier, 2010). The grasslands second order in the village Baisoara exploited by mowing, grazing or mixed. The grasslands in the Apuseni Mountains have a high diversity (Michler et al., 2005) which is strongly influenced by man- agement applied (Stoie, 2011). Increasing trophic- ity of grasslands by using liquid fertilizers, shows a new system of mineral fertilizer natural grasslands anticipated effects refers to improving the quality, productivity, and floristic composition. The aim of this paper was the effect of fertili- zation with liquid fertilizer (UAN) on the harvest of dry and floristic composition changing on natu- ral grassland. MATERIALS AND METHODS The experiment whose results we present was placed in 2014 in the place in Baisoara Mountain village, Cluj county, at the altitude of 1240 m. The experience was placed after experimental tech- nique method. The surface of experimental plots is 20 m 2 .The experience includes four variants in three repetitions, which are: first variant (V1) – control variant, (unfertilized); the second variant (V2) – fertilizer with 50 kg UAN/ha-1; third va- riant V 3 – fertilizer with 75 kg UAN/ha-1 (V4) – fertilizer 100 kg UAN/ha-1. Experience has been placed on grassland Festuca rubra - Agrostis capillaries type of that is specific of nemoral floor, beech forest the sublevel