The effect of nitrogen fertilization on the productivity of natural grassland Agrostietum vulgaris type

In the hilly and mountainous area of Republic of Srpska natural grasslands (meadows and pastures) represent significant resource for grazing and production of bulky livestock food. However, in addition to the big importance and available areas, the production of bulky fodder on natural grasslands are relatively low. Limiting production factors of feed in mountainous areas are the quality of the soil and the climatic conditions. Low yields of hay of natural grassland can be improved by application mineral fertilizers. In addition to the application of mineral fertilizers, which should be one from implementation of basic agrotechnical measures more profitable plant-based, ultimately and animal production it is necessary to apply appropriate quantities of fertilizers at the most suitable time of growing season herbal type. The goal of this research was to determine the influence of different amounts of nitrogen on productivity of natural grassland type Agrostietum vulgaris on low available phosphorus and potassium soil. This study was carried out in two seasons (2018 and 2019). The application of nitrogen had a positive impact on grassland productivity. The highest average green forage yield of 13.15 t ha-1 and hay yield of 3.48 t ha-1 was achieved with the application of 94.5 kg ha-1 of nitrogen, and the lowest was achieved in control without fertilization. The average increase in hay yield in the first year was 37.6% and in the second year it was 5.6% higher than in the first year. The application of mineral fertilizers on natural grasslands on low phosphorus and potassium soil is of crucial importance for obtaining higher yields of green forage and hay.