The study was carried out in a long-term fertilization field experiment of the Experimental Station of University of Pannonia, Department of Crop Science and Soil Science in 2006. The Long-term fertilization experiment was set up in 1983. In the experiment, the success of the weeds ability to grow under the influence of NPK, NPK + FYM* and NPK + straw treatments was compared, and the effect of increasing Nitrogen dosing on weediness was studied. The bifactorial test was arranged in split plot design with three replications. Treatment A: nutrient: NPK, NPK + 35 t/ha FYM* and NPK + straw manure. Treatment B: N kg/ha(-1) N0-N4 (0, 70, 140, 210, 280), and 100 kg P2O5 ha(-1) & 100 kg K20. The weed survey was made on 2nd of May 2006. There were spraying no herbicide until the survey. For the weed survey the Balázs-Ujvárosi coenological method was applied. Altogether, we have found 23 weed species in the trial. In the NPK treatment there were 20 species, in the treatment NPK+organic manure there were 17 species and in the NPK+ stalk rest treatment there were 16 weed species. The most dominant of the weeds on the NPK and NPK+straw manure treatments was Veronica hederifolia while on the fertilizer + FYM, the A. theophrasti was most dominant. The average weed covering value of the treatment NPK + FYM was 1.36 times higher (10.87%) than that of treatment NPK only (7.97%) and 3.65 times higher than on the NPK + straw manure treatment.