Assessment of Multiple Interactions between Soil Texture, Aggregate Size and Soil Thermal Properties

Soil thermal properties are highly dynamics and is influenced by a multitude of factors. Soil thermal properties affect soil temperature and its thermal regime. Soil water content, soil contribution and state of aggregation affect significantly soil thermal properties. The aim of this study was to determine and evaluate the effects of soil texture and aggregate size on soil thermal properties using the de Vries model. Soil samples with different textures, separated into different aggregate size groups (<4 mm, <2 mm and <1 mm), were used. Thermal properties of soil samples including thermal conductivity, volumetric heat capacity and thermal diffusivity were estimated at field capacity. The results showed that the maximum values for the thermal conductivity, volumetric heat capacity, and thermal diffusivity occurred medium (MTS)>fine, (FTS)>coarse, (CTS) textured soils. In all textural groups thermal conductivity and thermal diffusivity were the smallest in aggregate size <1 mm. Results indicated that soil texture and aggregate size distribution have great effect on the soil thermal properties