EFFICIENCY OF NITROGEN FERTILIZATION IN WHEAT AND BARLEY GROWN UNDER DIFFERENT FERTILIZATION SYSTEMS

Agronomic efficiency and Partial factor productivity of N were studied in wheat and barley grown in a long-term fertilizer trial and fertilization systems: Control, N300P400K600+18 t vetch-oat mixture/ha, N600P400K600 (stock fertilization), N900P400K600, N600P400K600+30 t manure/ha, N600P400K600+4 t straw/ha, N600P400K600 (annual fertilization) (& Iukcy;-& Iukcy;V crop rotations); Control, N300P300K400, N600P300K400, N900P300K400, N600P300K400+40 t manure/ha, N600P0K400, N600P300K0 (V-VII rotations); Control, N250P300K200, N500P300K200, N750P300K200, N250P150K0+60 t manure/ha, N500P0K200, N500P300K0 (VIII rotation). The studied rates were N-60, N-120, N-180 (wheat) and N-40, N-80, N-120 (barley). A high efficiency of N-60 and N-40 was found when N was incorporated into organo-mineral fertilization systems. Appling of 18 t vetch-oat mixture center dot ha or 60 t manure center dot ha increased Agronomic Efficiency of N (AE-N) and Partial Factor Productivity of N (PFP-N) to 54.5-71.3 and 81.8-112.8, respectively. The prolonged exclusion of phosphorus fertilization in the crop rotation strongly decreased AE-N and PFP-N up to 0.7-13.7.