Nikonenko V. Optimization of mineral fertilizer norms for winter wheat depending on the level of fertility of chernozem typical of Left-bank Forest-steppe of Ukraine

Object - a system of crop fertilization and processes of transformation of nutrients in the soil. Purpose - to develop methods for optimizing the rates of mineral fertilizers for winter wheat and mathematical models for predicting its yield at different levels of chernozem fertility of the typical Left-Bank Forest-Steppe of Ukraine. Methods - field, chemical, system, calculation, statistical, multifactor regression analysis. Theoretical results - theoretical approaches to solving the scientific and practical problem of optimizing the rates of mineral fertilizers for winter wheat at different levels of fertility of chernozem of the typical Left Bank Forest-Steppe of Ukraine; new knowledge on the patterns of long-term use of certain types of mineral fertilizers and their combinations on soil fertility indicators, based on which models of optimization of mineral fertilizers for winter wheat and mathematical models for forecasting winter wheat yield due to natural soil fertility and fertilizer application. Practical results - research results were included in the recommendations: "Scientifically based system of fertilization of field crops adapted to modern conditions of agriculture in the Left Bank Forest-Steppe zone of Ukraine", "Optimization of chernozem nutrient regime typical for high quality products", "Scientific support in agriculture modern technologies for growing cereals ", etc. A patent for a utility model "Method for determining the optimal dose of nitrogen fertilizers for fertilizing cereals during the growing season" was obtained. Novelty - for the first time: for conditions of insufficient and unstable moisture of the Left Bank Forest-Steppe of Ukraine the optimal norms of mineral fertilizers for winter wheat are substantiated and mathematical models of forecasting its yield on chernozems typical for different levels of fertility are developed; regularities of influence of separate kinds of mineral fertilizers and their pair combinations on productivity and quality of grain of winter wheat are established; the influence of long-term application of fertilizers on the dynamics of physical, physicochemical and agrochemical parameters of the soil is determined; normative indicators of mineral fertilizers consumption have been developed to increase the content of mobile compounds of nitrogen, phosphorus and potassium in the soil by 1 mg / kg of soil. The system of winter wheat fertilization with optimal norms of mineral fertilizers has been specified: on the natural agro background there is N57Р103К0, which provides a yield of 6.46 t / ha, protein content in grain 12.9%, gluten - 25%; on the agro background of manure aftereffects (240 t / ha)  N48Р87К0, which provides a yield of 6.73 t / ha, protein content in grain - 13.8%, gluten - 25%. The issues of mathematical planning of field experiment schemes for further study of the interaction of various factors influencing crop yields, product quality and soil fertility were further developed. Degree of application - the results of research have been tested and implemented in PJSC "Agrokombinat" "Slobozhansky" Chuguiv district of Kharkiv region. The materials are included in the educational process of Kharkiv National Agrarian University named after V.V. Dokuchaev. Branch - agriculture.