The Influence of Mineral Fertilization on Winter Wheat Yield and Quality

The effect of the N, P and K fertilisation on yield and quality parameters of cultivar Žitarka during two growing seasons (2002/03 and 2003/04) was studied. Fertilization increased yield, although only treatment with 200 kg N ha−1 yielded significantly higher than treatments with 80 kg N ha−1. Protein content increased significantly (P<0.001) with the application of 80 kg N ha−1, 120 kg N ha−1 and 160 kg N ha−1. The highest N applications with 200 kg N ha−1 and 240 kg N ha−1 increased protein content on the same level as with 160 kg N ha−1. Wet gluten and sedimentation value were also significantly (P<0.001) affected by N fertilizer treatments. Although increment of N fertilization increased values of these quality parameters, 120 kg N ha−1, 160 kg N ha−1 and 200 kg N ha−1 treatments showed similar effect, while treatment with 240 kg N ha−1 resulted with significantly higher values. Gluten index increased only with applying 80 kg N ha−1 while the highest N levels (200 kg N ha−1 and 240 kg N ha−1) showed dramatically gluten weakening. Considering grain hardness only treatment with 80 kg N ha−1 had significant (P<0.001) influence. Simultaneously, P and K did not affect grain yield and quality, neither comparing PK to controle, or N2P1K1 to N2P2K2.