Reznichenko N. Productivity of winter barley varieties depending on the main tillage and fertilizer under irrigation conditions in the South of Ukraine

The dissertation highlights the results of research on the development and improvement of elements of winter barley cultivation in irrigation of the South of Ukraine depending on varietal composition, methods of basic tillage and fertilizer in order to maximize the potential of crop productivity and quality, study their response to agronomic measures. It has been experimentally established that, in the cultivation of winter barley varieties on dark chestnut soil, it is expedient to use disc tillage to a depth of 12–14 cm which under the application of mineral fertilizers N120P40 on the background of wrapping of plant residues of the predecessor in the soil provides the highest grain yield of winter barley under irrigation conditions at the level of 6,06–6,47 t/ha. Experimental studies have determined the positive effect of mineral fertilizers on the productivity of winter barley varieties. When increasing the dose of fertilizers from N60P40 to N120P40 in the Dostoyny and Zymovyy varieties on the variants of all methods of basic tillage, the intensity of tillering increased by 6–16 % and 11–29 % respectively, accumulation of raw mass by plants increased by 40–60 % and 32–89 %, the leaf surface area increased by an average of 33–74 %, the structure of the crop improved, the protein content in the grain increased by 0,33–1,63 % and 0,5–1,23 %. The calculation of economic efficiency showed that the highest indicators were marked by the variant of disk tillage to a depth of 12–14 cm with the application of mineral fertilizer N120Р40. According to the results of three years of research, the winter barley Dostoyny provided a profit of 13067 UAH/ha at a level of profitability of 142,7 % and a cost of UAH 1442, and the Zymovyy variety of a profit of 12273 UAH/ha at a profitability of 133,2 % and a cost of 1501 UAH. The highest energy coefficient – 3,7 was provided by the variety Dostoyny for disc tillage to a depth of 12–14 cm with the application of mineral fertilizers at a dose of N120P40. In the Zymovyy variety, the energy efficiency ratio was slightly lower and amounted to 3,53. It should also be noted that the lowest energy factor for each variety was for sowing barley in uncultivated soil against the background of 7 years of zero tillage in crop rotation and fertilizer application rates N60P40 – 2,85 and 2,78, respectively. Key words: winter barley, irrigation, tillage, fertilizers, yield, yield structure, quality, economic efficiency, energy assessment.