Borodin A. Agrophysical properties of the soil sowing layer as a basis for improving the technology and tools for the pre-sowing treatment

The object – the dynamics of the agrophysical properties’ parameters of the soil in different interlayers of the seed layer after the conventional seedbed preparation and as a result of seedbed preparation by the newest tool, the effect of the pressure of the working organ of the pre-sowing tool on the parameters of the lumps crumbling and the physical and mechanical properties of the seed layer of the soil. The purpose – to compare the agrophysical parameters of the sowing layer of the soil (structural composition, bulk density, penetration resistance, moisture content and others), created by the conventional and experimental tools, to improve the method of seedbed preparation assessment, to specify agronomic requirements for seedbed preparation, to evaluate the influence of the seedbed preparation quality of on agrophysical properties of soils during vegetation of crops. Methods – field, laboratory, statistical, calculation-comparative. Theoretical results – the dynamics of agrophysical and physicomechanical properties in separate layers of the sowing layer – the overseed, seed and underseed was specified; it was determined that the agrophysical properties of the sowing layer of soil, formed as a result of conventional seedbed preparation and as a result of seedbed preparation by the newest tool, do not meet the current agronomic requirements; on the basis of the established parameters of the crumbling and fractional composition of the lumps formed during seedbed preparation, agronomic requirements was formulated with respect to the maximum permissible normal stresses to the lumps (at different moisture content), which does not exceed the threshold of plasticity. Practical results – it is suggested to evaluate the quality of seedbed preparation in separate layers of the sowing layer - the overseed, seed and underseed according to the agro-physical indices; the newest requirements for seedbed preparation seedbed preparation and tillage tools are grounded in terms of providing the optimum conditions for the crumbling of the lumps and on the maximum allowable normal stresses to the brittle lumps (for physical maturity); the addition of the index of fissure of the soil surface to the list of indicators of the physical state of the soil during the growing of agricultural crops creates an opportunity to more accurately assess the need for agrotechnical measures to loosen the soil surface. Novelty – is to establish the parameters of the crumbling and fractional composition of the lumps created during seedbed preparation of the soil, formulated agronomic requirements with respect to the maximum allowable normal stresses to the lumps (at different moisture content), in which the threshold of plasticity does not exceed; for the first time, conditions have been defined for minimizing the number of barns in the crop layer; the newest multidimensional models of determining the bulk density by penetration resistance and moisture content in the crop layer were substantiated; a method of quantitative estimation of the creep soil fragmentation during the growing of crops was developed; for the first time, a regression model for the development of fracturing of the surface of chernozem soils has been developed. The degree of implementation – the specified agroforests for pre-sowing cultivation of chernozem soils and the newest implements for pre-sowing tillage of soil have undergone a production inspection at the enterprise "Ukr. Agro-service "on the area of 0,5 hectares and in the submarine" Slobozhansky experimental field "of the NSC" IGA named after O.N. Sokolovsky ". Industry – agriculture.