INFLUENCE OF ORGANIC AND MINERAL NITROGEN FERTILIZATION ON WHEAT YIELD ON THE REDDISH PRELUVOSOIL IN THE DANUBE PLAIN

Research was performed in the course of a bifactorial experiment of 3x5 type made according to the split plot method aimed to study nitrogen organic and mineral fertilization on winter wheat in a winter wheat - winter barley - sugar beet crop rotation. The findings were that organic fertilization with 30 t/ha manure and 5 t/ha sugar beet leaves and crowns determined very significant production boosts of 5.78 q/ha and 5.63 q/ha respectively compared to the unfertilized treatment and the nitrogen mineral fertilization with no organic fertilization generated very significant production boosts up to the dose of N-150 where the production boost was of 16.29 q/ha. Combining organic fertilization - the after-effect of 30 t/ha manure - and mineral fertilization -N-150 led to maximum production of 46.35 q/ha. Highest nitrogen valuation coefficient of 12.38 kg wheat/kg N a.s. was recorded in the organic fertilization with 30t/ha manure, followed by the N-60, then by the treatment with no organic fertilization combined with the dose of mineral nitrogen of N-60 with 11.47 kg wheat/kg N a.s.