The aim of research was to determine the bioclimatic coefficients as well as the characteristics of their constituents on the basis of scientific and analytical studies and statistical analysis of long-term experimental data on summer planting potato cultivation under the conditions of the Lower Don floodplain, which are aimed at creating new computational models ensuring the rational use of water and energy resources, high productivity of potato cultivation, soil fertility preservation and increase, creation of favorable ecological situation of irrigated cultivated lands. When calculating bioclimatic coefficients, the S. M. Alpatyev and A. M. Alpatyev model was used. In the result of conducted studies it was found out that the amount of evapotranspiration, the sum of active temperatures and the sum of air humidity deficits were about 376.2 mm, 1800.2 degrees Celsius and 1335.6 mbar on average respectively for the growing season 2012–2016. Bioclimatic coefficients, which are the ratio of the evapotranspiration value to the sum of the accumulated active air temperatures and the sum of air humidity deficiencies were 0.209 and 0.282 respectively. The dynamics of these bioclimatic coefficients over the vegetation period is described by empirical equations of the polynomial form of the second degree. Multiple correlation analysis found out that evapotranspiration variation is related to the sum of active temperatures and the sum of air humidity deficiencies by 79 %, and it indicates a close relationship between the elements under consideration.
Key words: evapotranspiration, sum of active air temperatures, sum of air moisture deficiencies, bioclimatic coefficients, statistical analysis, correlation coefficient, multiple correlation analysis, potatoes, flood plain of the Lower Don.
