Milenko O. Ecological and biological justification of soybean cultivation technology elements in the conditions of Left Bank Forest-Steppe of Ukraine

The research object: processes of growth and development, formation of yield and quality of soybean seeds depending on agrotechnical conditions of cultivation, interspecies competition of soybean crops with weeds depending upon agrophytocenosis model. The research purpose: ecological and biological substantiation of the elements of cultivation technology of early ripening and fast-ripening varieties having optimized seeding rates and methods of soybean crops care of drilling sowing in order to increase crop productivity and seed quality and to decrease herbicide impact on agrophytocenosis. The research methods: general scientific, field, laboratory, mathematical and statistical. Scientific novelty: possibility of soybean growing without after shoot emerge herbicides application on drilling sowing crops has been substantiated and experimentally proved for the first time. Practicability of growing varieties of early ripening and fast-ripening groups on the areas in the left-bank forest-steppe of Ukraine has been established. Influence of weather conditions, variety peculiarities, seeding rates and methods of crops care upon photosynthesis efficiency and preservation of soybean plants on drilling sowing crops which provide high plant productivity, yield and soybean seeds quality has been determined. Advisability of control of soybean crops photosynthesis activity during the vegetation with the help of agrotechnical measures has been proved. Dependence of quality characteristics of soybean seeds (content of protein and oil) upon agrotechnical factors and weather conditions of the year has been established. The results: the elements of variety technology of soybean cultivation that involve optimal seeding rates and methods of crops care providing high level of yield and seed quality and decrease herbicide impact on agrophytocenosis have been improved. Introduced elements of the cultivation technology provided yield gain of soybean varieties of 0.11-0.29 t/hа. The introduction level: Performance tests and introduction of the developed elements of cultivation technology were done in the condition of farm economy "Pidkova" in Orzhytsa district, Poltava oblast, farm economy "Dmytrenko V.S." in Reshetylivka district and private farm "Pryorillya" in Novi Sanzhary district, Poltava oblast on the total area of 112 hectares. The results have proved effectiveness of the introduced elements. Scope of implementation: research institutions of NAAS, NAS and the Ministry of Agrarian Policy of Ukraine, educational establishments, agricultural enterprises of Ukraine.