Agroclimatic assessment of soil climate of the Northern Black Sea coast region (using the example of corn)

Soil climate is a natural resource of a certain territory and a component of the natural environment. The soil climate is very important for crop production: germination of seeds of agricultural crops, dormancy of overwintering plants and perennial grasses, growth of the root system and plants' aboveground mass during the growing season, productivity of plants. The role of the soil climate is also clearly manifested during moisture- and heat-dependant periods when moisture lack or excess and low or high temperature in the upper soil layers may have a significant influence on reaction of plants to the environmental conditions and consequently on their productivity. When studying the soil climate, it is possible to adjust it following the agricultural needs. In connection therewith, the aim of the research is to determine the quantitative characteristics of the soil climate of the Northern Black Sea region using the example of corn. The object of the research: the Northern Black Sea region. The subject of the research: soil climate. The study applies classical methods of agroclimatic calculations and generalizations. The article presents the results of agroclimatic assessment of the Northern Black Sea region's soil climate using the example of corn in relation to such criteria as soil thermal resources and moisture/moisture availability resources of an individual crop. It specifies the results of quantitative agroclimatic assessment of the thermal regime of soils with different mechanical composition across the Northern Black Sea region as per the following indicators: a) date of soil temperature transitions through 10 ºC in spring and autumn on the top of the soil and at depths of 10, 20 cm; b) duration of a warm period with the temperature above 10 ºC for soils having different mechanical composition; c) combined total of active temperatures above 10 ºC on the top of the soil and at certain depths. The research also presents the results of agroclimatic assessment of moisture/moisture availability resources within the studied territory based on the following main indicators: optimum water demand, actual water demand, evaporation rate; moisture availability coefficient; moisture index by G. Т. Selianynov and moisture index by D. І. Shashko during a warm period with temperature above 10 ºC. The paper also includes the quantitative assessment of the relationship between soil moisture reserves at different depths (0–20 cm, 0–50 cm, 0–100 cm) and productive moisture reserves at the lowest moisture content and moisture availability values for corn crops.