Change and influence of agroclimatic conditions on oat yield in Yakutia

The results of the dynamics analysis of multi-year meteorological indicators and study of their influence on the yield of the released oat varieties in different agroclimatic zones of Yakutia are presented. It is shown that in the period from 1960 to 2021 the mean annual air temperature in Central Yakutia (Pokrovsk meteorological station) increased annually by 0.045 °C, from 1999 to 2021 – by 0.088 °C, the number of dry years in June increased from 67 to 92% due to a 21% increase in years with medium (HTC = 0.41-0.60) and very strong (HTC < 0.21) drought. In July, drought was recorded in 50% of the years, in August – in 38%. In all agroclimatic zones in the period from 2014 to 2021 for June – August the average daily air temperature annually increased by 0.16...0.34 °С and their sum by 14...28 °С, with precipitation decreasing by 3-16 mm and HTC value by 0.04-0.12 units. Climate change from 2014 to 2021 was 3 to 8 times more intense than from 1999 to 2022. There was a strong variability of yields of the released oat varieties in each agroclimatic zone: Central – from 0.38 to 2.14 t/ha (V = 60–73%), Zarechnaya – from 0.31 to 3.55 t/ha (V = 41–49%), Srednelenskaya – from 1.51 to 4.66 t/ha (V = 30–36%). The greatest annual decrease in grain yield of oat varieties (by 0.25–0.26 t/ha) was observed in arid agroclimatic zones – Central (Yakutsk SCTS) and Zarechnaya (Megino-Kangalassky SCTS) – compared to the wetter Srednelenskaya zone (Olyokminsky SCTS – by 0.10 t/ha). More significant influence on the yield in the Central and Zarechnaya zones was made by precipitation and HTC of the growing season (r = 0.77...0.84), in the Srednelenskaya zone – by temperature (r = – 0.79). Negative effect of temperature on the yield in the Central zone was observed in June (r = – 0.83), Zarechnaya zone - in July (r = – 0.83), in the Srednelenskaya zone – in August (r = –0.86). Precipitation and HTC had the greatest influence on the yield in the Central zone in June and July (r = 0.56...0.59), Zarechnaya zone – July and August (r = 0.60...0.76). In the Srednelenskaya zone the relationship of the yield with precipitation and HTC in June and July was positive (r = 0.23...0.37), in August – negative (r = – 0.57...– 0.71). Significant variability in grain yields of the released oat varieties indicates the variability of weather conditions and the need to cultivate oat varieties that provide a more stable yield in different agroclimatic zones of Yakutia.