The type of fertilizer and the method of its application are important factors influencing the process of optimisation of grassland fertilization. Foliar application of sward fortification with liquid fertilizers is gaining in importance again. Lists of fluid fertilizers offered by fertilizer distributors are getting longer and longer. In our experiments, we used the following two fertilizers: a highly concentrated aqueous solution of ammonium saltpetre and urea frequently referred to in Poland as RSM and, from the group of liquid multi-component fertilizers, Basfoliar 12-4-6 containing 12% N, 4% P and 6% K as well as some macro- and microelements. Traditional fertilization using ammonium saltpetre, potassium salt and superphosphate was treated as the control object, while the experimental plot with no fertilization was used as a control. The subject of the experiments included a permanent pasture and a temporary pasture established by sowing different cultivars of Lolium perenne. The results of our experiments show that the saltpetre-ammonium and Basfoliar 12-4-6 solution can be considered as interesting fertilizers which can fortify plant elements of the pasture sward with nutrients. Changes in the quantitative and qualitative botanical composition of the pasture sward appear to confirm the specific response of plant species to the application of nutrients contained in fluid fertilizers. The application of foliar fertilization of the sward pasture with RSM and Basfoliar 12-4-6 allowed obtaining fodder of good qualitative parameters comparable with those found in the pasture sward fertilized traditionally, i.e. with ammonium saltpetre and superphosphate. The mode of action of the RSM and Basfoliar 12-4-6 is similar to that of ammonium saltpetre. Wider possibilities of their application will depend on their price as well as costs of their application.