Climate change accelerates global warming and has thus become an increasing concern with need for prompt solutions. This process occurs due to increased atmospheric green house gas (GHG) emissions. The agro sector (crop and livestock agriculture) contributes 10 to 12% per year of the total global anthropogenic emission and tends to increase. Most agricultural GHG emissions are generated by intensively fertilized soils, enteric fermentation, and manure management. Remarkable GHG fluxes occurred from grasslands which occupy 69% of global agricultural land. The aim of this investigation was to evaluate and estimate GHG emissions in natural and abandoned grassland improved by managed fertilizing. Experimental data sets cover grassland (clay loam topsoil over silt loam, Calc(ar)i-Endohypogleyic Luvisol) abandoned more than 20 years, which has subsequently been fertilized with different rates of N and multiple NPK. Direct CO₂, N₂O, and CH₄ emissions were measured in differently studied treatments (semi-natural sward: Control (0), N₆₀, N₁₂₀, N₁₈₀, N₂₄₀, N₁₈₀P₁₂₀, N₁₈₀K₁₅₀, N₆₀P₄₀K₅₀, and N₁₈₀P₁₂₀K₁₅₀; cultural pasture: N₁₈₀P₁₂₀K₁₅₀) during vegetation period (2009). Decreasing tendency of emission fluxes was determined during vegetation period and employing lower fertilizer rates. Therefore, appropriate fertilizing rate (N₆₀P₄₀K₅₀) of extensive grassland should be considered for its mitigating impact on climate change.