Dudka M. Agrotechnological bases of productivity improvement of annual forage crops in the Northern Steppe of Ukraine

Object of study: the processes of growth, development of love-lies-bleeding (Amaranth paniculate /Amaranthus paniculatus L.) plants for once-cut use and two-cut use and annual forage crops in combined different species of winter, spring and postcutting crops; regularities of productivity formation depending on the agrotechnological factors at application of effective technological methods of growing for increase of yielding capacity and quality of green weight and grain (seeds). Methods: field, laboratory and statistical. Results: the technology of growing of love-lies-bleeding for green fodder and grain was developed, which in the conditions of natural moisture of the Northern Steppe of Ukraine provides the yielding capacity of green mass 28.02–29.80 t/ha, collection of absolutely dry matter – 5.13–5.16, fodder units – 3.72–4.04, digesting protein – 0.56–0.61 t/ha and grain yielding capacity – 1.36–1.77 t/ha. The scientifically substantiated species composition of maturing at different times winter, early and late spring and postcutting agrophytocenoses on the basis of new, a little propagated and traditional annual crops with rational use of their species and varietal composition and bioclimatic potential of the Northern Steppe of Ukraine, that which increases the productivity of crops and prolongs the period of green mass supply is proposed. The results of research were tested in production conditions and implemented in 2016–2018 in farms of various forms of ownership of the Dnipropetrovsk region on the area of 2270 hectares, that provided annual additional profit (at the prices of 2019) 1.2–4.3 thousand UAH/hectare. Novelty: for the first time in the Northern Steppe conditions theoretically substantiated and experimentally proven the expediency of introducing in the culture of love-lies-bleeding with different directions of use, determined the influence of basic agronomic methods on the level of productivity of love-lies-bleeding during its growing on green mass and grain in single-species crops, established the peculiarities of growth and formation of plant productivity of love-lies-bleeding with two hay cutting use of crops and in agrophytocenoses in combination with maize, sweet sorghum, sorghum-Sudan-grass hybrid. The species composition of different species winter, early and late spring and postcutting agrophytocenoses has been improved on the basis of scientifically substantiated selection of new, a little propagated and traditional annual crops, ecological and biological parameters of yielding capacity formation of different species agrophytocenoses of annual crops for different directions of use of species and variety composition and agroclimatic potential of Steppe zone, scientific provisions for obtaining two or three harvests of annual crops per year in the growing of postcutting agrophytocenoses in the conditions of natural moistening of the Steppe.