S. N. Nemzev, R. B. Sharipova
Ulyanovsk Agricultural Research Institute, branch of the Samara Scientific Center, Russian Academy of Sciences, ul. Institutskaya, 19, pos. Timiryazevskoe, Ul’yanovskii r-n, Ul’yanovskaya obl., 433315, Russian Federation
Abstract. The purpose of the studies was to assess the features of the warm period and the relationship of its characteristics with the yield of grain crops in the Ulyanovsk region. Information on the dates of the transition of air temperature through 0 C, +5 C, +10 С in spring and autumn; duration of periods; sums of active temperatures; hazardous environmental phenomena (frosts) were taken from meteorological yearbooks for 1990–2019; the data on the grain yield was taken from the Rosstat register. To study long-term changes in the duration of the periods at six meteorological stations (Inza, Surskoe, Ulyanovsk, Dimitrovgrad, Sengiley, and Kanadei), we used the Fourier series expansion, methods of discriminant, as well as correlation and trend analyses. The temperature transition through 0 С in spring occurs in the region on average on March 29; in autumn this happens on November 9; thus, the period lasts 225 days; the temperature transition through +5 С occurs on April 14 and October 18 (the period lasts 188 days); temperature transition through +10 C occurs on April 28 and September 29 (the period lasts 154 days). The sum of active temperatures (t less than 10 C) of air in the Ulyanovsk region for 30 years increased on average by 200–270 C and is now 2,499 C, which is enough to fully meet the heat needs of not only grain crops but also of early ripening corn hybrids for grain and grain sorghum, as well as the needs of sorghum hybrids. In the dynamics of the duration of the frost-free period, we did not note any significant changes that could affect the yield of grain crops. In general, changes in the regional climate over the past three decades had a positive impact on the productivity of crops.
Keywords: date of temperature transition; duration of the warm period; sum of active temperatures; frosts; productivity.
Author Details: S. N. Nemzev, D. Sc. (Agr.), director; R. B. Sharipova, Cand. Sc. (Geog.), senior research fellow (e-mail: Этот адрес электронной почты защищён от спам-ботов. У вас должен быть включен JavaScript для просмотра.).
For citation: Nemzev SN, Sharipova RB [Agroclimatic resources, their changes, and ecological restrictions of the growing season in the Ulyanovsk region]. Dostizheniya nauki i tekhniki APK. 2021;35(3):10-4. Russian. doi: 10.24411/0235-2451-2021-10302.