Seasonal temperature regime in the profile of sod-podzolic soil under garden strawberry plantations in the Altai Region’s Ob River area

Abstract

The main factor for increasing berry crop yields is the formation of favorable agrophysical properties and thermal and moisture regimes in the soil profile since they ensure the intensity of biological processes, the nutritional regime and, thereby, the vital activity of plants. In this case, heat flows in the soil are directly determined by the distribution of thermal fields in its genetic horizons. The object of research was sod-podzolic irrigated soil. The research target was the temperature regime of the genetic horizons of the soil profile during the autumn-winter-spring seasons of 2022-2023. At the end of October 2022, high positive temperatures occurred in the humus horizon to a depth of 25 cm. But at the beginning of November there was quick cooling which caused gradual cooling of the soil. The accumulated temperature in the chernozem profile during the same time dropped to +5°C, and the maximum outgoing heat flow at the end of autumn was -6.6 W m². The presence of snow cover in December protected the soil from freezing. During three winter months, its surface temperature dropped to only -2°C. A long period of stabilization of the thermal regime was observed in the underlying chernozem horizons. The heat flow value was stable from early January to mid-February. In the spring of 2023, a complete stabilization of the thermal regime occurred in the soil thickness to a depth of one meter which persisted for a month. Thus, in the 0-50 cm layer the temperature was zero, and at 100 cm it was 1.5°C. In April the soil began to warm up. During May it increased to 22°C at the surface and 10°C at one meter depth. The heat flow remained zero until April 5. From mid-April it became positive reaching +30.8 W m² by mid-May.