The role of meteorological factors in the formation of long flax productivity in the Forest-Steppe of Western and Polissya

Abstract

Purpose. Theoretically substantiate and develop mathematical models for the feasibility of locating fiber flax in the soil-climatic zone of Polissya and the Western Forest-Steppe zone of the directly in the region, including its bioclimatic potential. Methods. Dispersion, factorial, correlation, and regression methods were used to analyze statistical data and determine their probability. The analysis of weather conditions and the level of their variability for the period 2000–2020 in comparison with average longterm indicators were carried out on the basis of criteria of coefficient of materiality of deviations (Ks) of elements of an agrometeorological mode of each of investigated years from average long-term. Results. The analysis of statistical data for 2000-2016 shows that the stability of the formation of fiber flax yield in the Forest-Steppe zone is almost absent (R2 = 0.1594) and unstable, both due to time gaps and yields of individual regions of the zone. Fiber yields varied significantly from 0.36 tons (2003), 0.42 tons (2007), to 1.40 tons (2006) and 1.25 tons (2013). Observations and analysis of meteorological phenomena in Ukraine indicate regional climate change. An increase in the average annual air temperature, a change in the duration and increase in heat supply of the flax growing season and a significant increase in the number and intensity of adverse meteorological phenomena, even in the regions. The frequency of adverse weather conditions in the amount of precipitation varied between 41-58 cases. The largest number of them was observed in Zhytomyr (58 cases), Volyn (54 cases) and Ivano-Frankivsk (53 cases) regions. It was established that April (R = 0.326, D = 10.6%) and June (R = 0.483, D = 23.3%) had a moderate relationship between the moisture supply of the growing season months and the productivity of long flax in the zones of Lviv region. The remaining months were significantly correlated between R = 0.501–0.629, D = 25.1–39.6%. Based on the results of regression analysis of the influence of the set of temperature regime and precipitation distribution during the growing season of flax, a mathematical regression model of crop yield formation for Polissya zone was developed, which shows that on average for the zone the connection has moderate strength 15.4%. Conclusions. Weather conditions of the soil-climatic zone do not have a significant impact on the formation of flax yield, i.e. are plastic in relation to the yield level. According to the calculation of the multiple correlation coefficient of the complex of weather conditions, it was determined that the high level of closeness of the connection with the yield of long flax fiber was decisive for: Volyn reg. – May (R = 0.950, D = 90.3%); Zhytomyr reg. – May (R = 0.812, D = 65.9%); Ivano-Frankivsk reg. – July (R = 0.679, D = 46.1); Lviv reg. – July (R = 0.702, D = 49.3%): Rivne reg. – July (R = 0.773, D = 53.7%); Chernihiv reg. – April, July, August (R = 0.749–0.773, D = 56.1–59.8%).