Influence of vermicompost aftereffect on the efficiency of spring barley cultivation in arid conditions of the Steppe of Ukraine

Barley is a crop, requires the availability of available nutrients in the soil, especially at the be-ginning of the growing season. The aim of the research was to determine the effectiveness of the aftereffect of using vermicompost when growing spring barley on different backgrounds in the Donetsk region. The studies were carried out according to the methodology of the field experiment of B. A. Dospehova. Research methods: field, supplemented by analytical studies, measurements, calculations and observations. The studies were conducted in 2017–2019 by laboratory-field method in field crop rotation in the experimental sections of the Donetsk SSES NAAS. The repetition in the experiments is 3-fold. The location of the plots is systematic. The soil is alkaline-chernozemic carbonate, having an average supply of mineral nitrogen and mobile phosphorus, low – potassium. The humus content of 4,2 % indicates a high potential soil fertility, but to realize the potential of the culture, additional application of phosphorus-potassium fertilizers is necessary. The technology for growing crops is generally accepted for the farms of the region, with the ex- ception of the factors studied. Variety of barley spring Avers. The experience scheme provides for: control (without fertilizers); background – saturation of crop rotation with vermicompost granular 2 t/ha; background + N30P30K30; background + N60P60K60; N30P30K30. The use of organic fertilizers under the predecessor in crop rotation provided improve nutriti-on conditions for plants, which positively affected the growth and development of spring barley plants. So, on the variants with the use of mineral fertilizers, the highest indices of the number of productive stems and the structure of the crop were noted in the background. The variant where N60P60K60 was added in the background produced the largest mass of 1000 grains – 49,8 g, which is 4,6 % higher than the control. Analysis of the study indicates the positive effect of the aftereffect of organic fertilizer (ver-micompost) on the yield of spring barley. The maximum yield of spring barley was obtained against the background of aftereffect of vermicompost 2 t/ha and the application of mineral fertilizers N60P60K60 – 5,05 t/ha, but due to high production costs, the profitability level is 114,9 %. The application of organic fertilizers under the background provides a yield of 3,67 t/ha and the highest level of profitability of 140,6 %. The optimal technological option provides for the introduction of mineral fertilizers in the norm N30P30K30 amid predecessor saturation with vermicompost. This allows increasing the yield up to 4,90 t/ha (by 1,46 t/ha or 42,4 % to the control) and obtaining a profitability level of 136,1 %. The use only of mineral fertilizer N30P30K30 in severely arid weather conditions of the steppe zone allows increasing the yield by 0,70 t/ha compared to the control but, due to the high cost of pro-duction, leads to a low production profitability of 99,6 %. Key words: spring barley, background, vermicompost, mineral fertilizers, yield, economic effici-ency.