A.A. Fedotov1, S.A. Lihodievsky1, A.I. Khripunov2
1Prikumskaya Experimental Breeding Station, Vavilova Str., 4, Budenovsk city, Budenovsk district, Stavropol region, 356803, Russia
2Stavropol Research Institute of Agriculture, Nikonova Str., 49, Shpakovsky district, Stavropol region, 356241, Russia
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Summary. In long-term stationary field experiment (1971-2013) in connection with parameters of hydrothermal coefficient (HTC) the recurrence of droughts in spring-summer (April-June) and summer-autumn (July-October) periods in arid zone of Stavropol region was estimated and its influence on winter wheat productivity was revealed. For 43 years of the research the probability of all types of droughts was 165.1 % with predominance of strong (HTC = 0.31…0.50) and very strong (HTC < 0.30) two-three month long summer-autumn droughts. The occurrence of spring-summer droughts was 67.4 % and among them strong (34.8 %) and one-month (48.8 %) droughts prevailed. Among all types of droughts by frequency of occurrence strong ones (83.4 %) leaded, than were very strong (62.8 %) and medium (HTC =0.51…0.60; 18.6 %) droughts. Spring-summer droughts were most harmful: one-month drought reduced the grain harvest on average at 3.7 %, two-month – at 19.2 %, and three-month –2.7 times. Every two years of three the combined effect of different types of droughts occurred. A high probability of summer-autumn droughts (97.7 %) proves the necessity of inclusion of clean fallows in crops rotation as a preceding crop for winter wheat. The efficiency of its usage was pointed out by the productivity of the second winter wheat, which was only 53…59 % from the level of wheat yield, seeded after clean fallow. In the years with sufficient precipitations the impact of seeded fallows increased. When the average annual precipitations was 372.8 mm (1971-1980), the average yield of grain after clean and seeded fallows was 3.27 и 2.33 t/ha, and with increase in the number of precipitations up to 452.2 mm (2001-2010) – 4.73 and 4.38 t/ha, correspondingly. The difference in crop yield after these fallows with enhancement of the moisture conditions decreased from 0.94 to 0.35 t/ha or 2.7 times.
Keywords: drought, productivity, winter wheat, duration, type, intensity, probability, vegetation period, preceding crops.
Author Details: A.A. Fedotov, Leading Researcher (e-mail: Этот адрес электронной почты защищён от спам-ботов. У вас должен быть включен JavaScript для просмотра.); S.A. Lihodievsk, Head of Division; A.I. Khripunov, Cand. Agricultural Sci., Head of Division.
For citation: Fedotov A.A., Lihodievsky S.A., Khripunov A.I. Impact of drought on winter wheat crop yields. Dostizheniya nauki i tekhniki APK. 2014. T.28. №11. pp. 19-21 (In Russ)