The Study of Possible Soybean Introduction into New Cultivation Regions Based on the Climate Change Analysis and the Agro-Ecological Testing of the Varieties

Abstract

Analyzing agro-climatic conditions for the period of 1981–2020 has revealed a tendency for local climate warming under the condition of its aridization in the territory of the Central region of the Russian Non-Chernozem zone, and the new northern borders for soybean growing in the region have been marked. The isotherm of the sum of active temperatures has been established to have shifted towards high latitudes by 150–200 km. The values of the sum of active temperatures have increased from 1700–2200 °C to 1950–2400 °C, while the amount of precipitation during the growing season has decreased by 20–40 mm on average, from 270–280 mm to 190–230 mm. Three agro-climatic subzones—northern (NAS), central (CAS) and southern (SAS)—have been identified, each characterized by similar temperature and humidity conditions during the growing season. Thus, in the northern agro-climatic subzone, the sum of temperatures during the growing season is 2000–2200 °C, the HTC (hydrothermal coefficient) is 1.4–1.7, and the sum of precipitation is 285–295 mm; in the central subzone, the sum of temperatures is 2200–2400 °C, the HTC is 1.1–1.4, and the sum of precipitation is 265–285 mm; in the southern one, the sum of temperatures is 2400–2600 °C, the HTC is 0.7–1.1, and the sum of precipitation is 255–265 mm. Along with the northern ecotype varieties recommended for this zone, the vegetation features of early maturing soybean varieties of other ecological types—southern and Far Eastern—were studied. As a result of the agro-ecological analysis of early maturing soybean varieties, it has been found that the soybeans belonging to the group of very early or early maturing with a determinant type of growth are recommended for cultivation in the northern agro-climatic subzone of the Central region of the Non-Chernozem zone; the soybean varieties belonging to the group of very early or early maturing with a determinant or semi-determinant type of growth—in the central zone; the soybean varieties belonging to the group of very early or early maturing with a determinant, semi-determinant, and indeterminant type of growth—in the southern zone. Considering the variety characteristics and the agro-ecological tests conducted, it has been found that the northern ecotype varieties can sustainably ripen in all agro-climatic subzones in the Central region of the Non-Chernozem zone, the southern and the Far Eastern varieties—in the central and the southern zones.