the combination of nitrogen and silicon fertilization, in adequate amounts, can increase rice grains yield and quality. this study aimed at evaluating the yield components, grain yield and milled quality of rice grains, primavera cultivar, according to the application of silicon combined with topdressing nitrogen fertilization, with and without irrigation, in selvíria, mato grosso do sul state, brazil. the experimental design was randomized blocks, in a split-split-plot arrangement, with four replications. the treatments consisted of cropping systems (rainfed and sprinkler irrigation) for plots, silicon doses (0 kg ha-1 and 100 kg ha-1) for split-plots and topdressing nitrogen doses (0 kg ha-1, 30 kg ha-1, 60 kg ha-1 and 90 kg ha-1) for split-split-plots. irrigation increased plant height and grain yield, and the silicon application did not affect grain yield and its components or the milled rice yield of irrigated rice. the rise of n doses, under sprinkler irrigation, increased plant height, number of tillers and panicles m-2 and total spikelets, as well as grain yield, however, for the rainfed system, rice yield decreased.