Dynamics of Temperature Variation in Soil under Fallow Tillage at Different Depths

Abstract

One of the important processes taking place during soil surface tillage is the variation of the soil temperature at different depths. The paper presents the results of research into the dynamics of soil temperature variation in terms of such parameters of the soil as its thermal diffusivity and temperature oscillation frequency. It has been established that the temperature oscillation amplitude decreases when the depth increases, following the logarithmic law. In this variation, the temperature difference between the 0–5 cm layer and the adjacent 5–10 cm layer has the greatest value. This circumstance is a favorable factor for the fallow tillage technology, where the soil is regularly cultivated to a depth of no more than 5 cm, in case of a moisture deficit. A decrease in the frequency of the soil temperature oscillations can result in the reduced level of its heating in different layers. In terms of qualitative changes, the reduction in soil thermal diffusivity results in the amplitude of the soil temperature oscillations being lowered and at the same time the maximum of these oscillations being shifted towards a delay.