Влияние агрометеорологических условий на урожайность эспарцета на зелёный корм в засушливой зоне Ставропольского края

Relevance . Agro climatic conditions play a decisive role in the formation of the yield of the green mass of sainfoin. Therefore, knowledge of the mechanism of the relationship between the plant and the external environment is relevant. Materials and methods . The experiment was carried out in 1971–2020 in the department of agriculture at the Prikumskaya experimental selection station. The aim of the research was to identify the influence of some agro meteorological factors on the yield of sainfoin on green fodder in the arid conditions of the Stavropol Territory. Results . Analysis of meteorological factors over 50 years of research indicates the cyclical nature of their development in time. At the same time, a steady increase in the average annual air temperature (1.2 °C) and the annual sum of active temperatures (248 °C) was revealed. The entire growing season from April to October is dry (Hydrothermal Moisture Coefficient = 0.69), but the driest period is from July to October (Hydrothermal Moisture Coefficient = 0.55). The size of the green mass of sainfoin yield mathematically reliably depends on the amount of precipitation in August-May (r = 0.55), March-May (r = 0.47) and March (r = 0.40). The amount of precipitation in August-May in 16% of years was less than 250 mm, in 24% of years 251–301 mm, in 26% of years 302–352 and 353–403 mm and in 8% of years more than 404 mm. In March-May, in 74% of years, precipitation was 61–153 mm, in 20% of years more than 154 mm, and in March in 66% of years it dropped to 33 mm, in 22% of years 34–48 mm and in 12% of years more than 49 mm. Productivity depends not only on the amount of precipitation in the most crucial periods of ontogenesis, their distribution during the growing season, but also on many other factors. The range of yield variation with the same amount of precipitation in August-May was 13.74 — 34.11 t / ha.