Effect of Fertilization and Liming on Crop Responses Field Crop Production 531 Effect of Fertilization and Liming on Crop Responses

The paper reports results achieved in the first 30 years of a 45-year-old field trial for fertilization and liming set up on acid sandy brown forest soil in the Nyírség region. The site was poor in all five major nutrients (N, P, K, Ca, Mg). The following conclusions could be drawn: Fertilizer responses were time dependent. In the 1st decade of the experiment N alone increased the potato and rye yields. In the 2nd decade, the yield on N-plots declined near to control. In the studied last few years, the yields on N-plots were negligible, the soil lost its fertility and became leached and very acid. To maintain or increase the yields of crops NPKCaMg fertilization was needed. Fertile plots have a pH (KCl) 5.5-6.0, 120-150 mg/kg ammoniumlactate-soluble P2O5 and K2O in ploughed layer and require the application of about 150 kg N and 1 t/ha ground dolomite yearly. Key words: liming, fertilization, long-term field experiment, crop response