Abstract: Addition of inhibitor to urea or ammounium sulfate resulted in significant increase in the yields of grain and straw. Combination of low rates of N and inhibitor resulted in 27.2 percent yield increase using Urea and 29 percent increase of ammonium sulfate. Applying N in one dose combined with inhibitor gave higher yield increases. The inhibitor increased wheat grain yield much more than straw yield, especially at low N rates, with higher rates the opposite was noticed. N, P and K uptake seemed to be affected with N-rate, dose and also the application of the inhibitor.