In a field trial set up on the research field of Agricultural station in Sombor, the effect of different fertilization systems and mulching on yield of pepper and mineral nitrogen (N) dynamics in soil were studied. Trial was conducted during 2010 and 2011 cropping seasons. Two varieties of pepper were grown with and without plastic foil as a ground cover, and on both mulching systems it was applied 240 kg N ha-1 in total, through different fertilization systems. Four organic fertilizers were applied: rotten beef manure (ZGS); composted pig manure (KSS); vermicompost (G) and Fertor (F). Each organic fertilizer was applied in three different amounts which contained 60, 120 and 240 kg N ha-1. On the same plots, mineral N fertilizers were added to fulfill target value for N application (240 kg N ha-1). The monitoring of NO3-N in soil during the pepper growing season has shown that the mineralization of organic fertilizers was most intense in the first half of vegetation, while in the second, during the yield formation, concentration of mineral nitrogen in soil was significantly reduced. Concentration of mineral N in soil under plastic mulch was significantly higher compared to plots without mulch. Yield of pepper in first and second term of harvest were positively correlated with concentration of mineral N in soil.