The best duration of the interfacial flowering-ripening period and its stability was the Gigantella variety, which was characterized by a coefficient of plasticity less than 1. The highest coefficient of agronomic stability, which was 97.9%, and homeostatic - 15.9, and the stability variant was the lowest among varieties which had been studied. In addition, high stability was provided by the variety Local Green, which along with a long period of flowering-ripening provided a low coefficient of variation, which was 4.3%, and the coefficient of agronomic stability was 95.7%, and homeostatic was 7.7, but the variance stability was higher than in the Gigantella variety. High indicators of stability were also provided by the Marmurov variety, which, along with a long period of flowering-ripening, was characterized by high stability of this indicator. Thus, the coefficient of plasticity - 0.78, the coefficient of agronomic stability was 95.4%, and homeostatic - 6.8. The weight of 1000 grains was distinguished by the variety Gigantella, which had a mass of 1000 grains was 457.2 g, also a high weight of 1000 grains provided a variety of Marble - 428.3 g. In addition, this variety provided relatively high stability, the coefficient of variation was 7.6%, and the coefficient of agronomic stability - 92.4%. Therefore, it is very difficult to combine the high mass of 1000 grains with the stability of this indicator. According to the coefficient of plasticity and the level of yield, the variety Gigantella stood out, which provided a yield of 2.64 t / ha, and the coefficient of plasticity was higher than one. In addition, this variety provided a high coefficient of agronomic stability - 90.1% and a coefficient of variation - 9.9%, homeostatic was the highest among the varieties studied and amounted to 0.27. Relatively high indicators of plasticity and stability provided Marmurov variety, which provided a yield of 2.28 t / ha, the coefficient of plasticity above one, as well as high stability, namely the coefficient of variation - 8.7% and the coefficient of agronomic stability 91.3% , and homeostatic - 0.26, the stability variant was as close as possible to zero.

The article presents economic assessment of technological methods of cultivation of switchgrass. The most effective technologic activities to ensure maximum growth yield of dry biomass of switchgrass and the highest econonomic efficiency. The highest efficiency was obtained at the variant where there have been two pre-cultivation before and after the rolling ladder. The varieties Сave-in-rock and Сarthage the third and fourth years the farming cost of production from the realization of biomass in this variant amounted to 11,875 and 15,390; 9,595 and 13,870 UAH/ha, and profit from sales of products – 4,157 and 7,381; 1,974 and 5,950 UAH/ha and profitability of Cave-in-rock – 92,2 and Сarthage – 75.1 per cent in the fourth year of vegetation. A high level of profitability obtained on the variant, where conducted, only two pre-cultivation the varieties of millet lozovenko the fourth year of vegetation: Cave-in-rock – of 87.0 and Сarthage was 69.2%. The cultivation of plants during second year of vegetation was not effective, the level of profitability at grades Сarthage from 25,6 to -43,3% and cave-in-rock from -12,6 to -36,7%. The highest indicators of economic efficiency were obtained in the variant with row-spacing width of 45 cm from plant switchgrass third and fourth year of cultivation. The varieties Cave-in-rock and Сarthage the cost from the sale of biomass amounted to 12635 and 15675; 7885 and 13870 UAH/ha, and profit from sales of products – 4844 and 7553; 493 and 5950 UAH/ha profitability of millet varieties depended primarily on year of vegetation, width of row spacing and varietal characteristics. The highest level of profitability obtained from varieties of millet the fourth year of vegetation with a width between rows 45 cm – 75.1% in the variety Cartage and 93.0% of the varieties cave-in-rock. A lower level of profitability obtained for the variant in terms of 2017, where inter-row spacing was 30 cm from millet varieties cave-in-rock – 73,6% and Cartage – 50.5 per cent. Key words: switchgrass, row spacing, pre-sowing soil.

The article presents the results of studying the effectiveness of options for biologizing the fertilization system and related factors of the impact of options for using post-harvest green manure in the technology of growing grain corn on gray forest and chernozem soils. The effectiveness of the use of cruciferous green manure crops, such as white mustard, oil radish and spring rape, has been investigated. Evaluation of the effectiveness of green manure was carried out both by the species factor and by the method of sowing green manure plants, in particular, the usual row and wide-row methods. The features of the influence of late autumn post-harvest green manure on the formation of agrophysical soil properties, such as the duty cycle in its categories and soil density, taking into account the optimization of the air properties of the soil and the restoration of its structure in the technologies of adaptive cultivation of agricultural crops, have been studied. The role of green manure crops in providing herbicide-free control of the level of weed infestation was assessed both from the standpoint of controlling the number of various types of weeds and from the standpoint of regulating their development and prevalence. The formation of segetal vegetation in crops of corn for grain was investigated in the format of determining the effectiveness of the aftereffect of green manure on the formation of the level of weediness in the late phenological phases of growth and development of corn. The features of the formation of leafy mass of green manure were investigated, taking into account the temperature and moisture regime.Based on this, an assessment was made of the adaptability of various types of green manure crops depending on the limiting factors of moisture and low temperatures in the variant of summer-autumn use. Conclusions are made about the expediency of using this criterion of the studied cruciferous crops. The influence of green manure crops on the formation of corn yield for grain is shown, taking into account different types of soils and their fertility potential, as well as taking into account the method of sowing green manure. Increases in corn yield were determined in comparison with unfertilized control and their level was assessed in relation to a possible effective alternative replacement of existing options for fertilizing corn with grain. Conclusions are made about the most productive green manure option based on cruciferous species, and prospects for further research and problematic aspects of the use of cruciferous green manure plants are outlined.

The article presents the results of studies of the effect of different doses of mineral fertilizers N90P90K90 and N120P120K120 on the productivity of corn. We studied the formation of green mass yield of corn in the following groups of maturity: medium-early hybrid Svityaz FAO 250, medium-ripe Aquazor FAO 320 and late-ripe Hetera FAO 420. During the growing season, corn plants were exposed to adverse weather conditions. The best weather conditions were observed in 2018 (SCC 1.34) and the worst were in 2016-2017 (SCC 0.64-0.81). Such weather conditions affected the growth processes of the crop in height, the indicators of which differed over the years and had the form of a sinusoidal depending on the phase of growth and development. In the ejection phase, the height of maize plants in the hybrid Svityaz FAO 250 was 197 cm, Aquazor FAO 320 - 199 cm and Hetera FAO 420 - 203 cm, which in the phase of wax grain ripeness increased to 262 cm, 263 and 276 cm, respectively, against N120P120K120. One of the indicators that characterize the green mass yield is the height of plants and the percentage of cobs and stems in the structure of biomass. According to our data, the largest share of cobs was on the variants without fertilizers, which was 40.6-43.1 and 37.3-42.1% on the maximum background of fertilizers. In this case, the cobs by weight were the heaviest and reached 197.0-216.7 g per plant using mineral fertilizers at a dose of N120P120K120. The increase in the yield of green mass of corn in the phase of wax ripeness by 1.29-1.58 times compared to N90P90K90 and N120P120K120 - 1.33-1.48 times, compared with harvesting in the phase of ejection of panicles. The highest yield of dry matter of corn was found by applying mineral fertilizers at a dose of N120P120K120, which was in the hybrid Svityaz FAO 250 - 22.46 t / ha, in hybrids Aquazor FAO 320 and Hetera FAO 420 - 25.13 and 28.03 t / ha, respectively. High digestibility of green mass of corn from the phase of ejection of panicles to milk ripeness, where the content of feed units in 1 kg of dry matter increases from 0.93 to 1.04.