Variation of the Soil Thermal Properties with Different Applications in Greenhouse Solarization

Solarization technology allows for improving soil quality as well as crop productivity. The efficiency of this technique is closely linked to soil thermal properties. Therefore, this study investigated the effects of different applications (dry-ice application (CO2), basaltic tuff (BT), various colored PE (VCPE), organic matter (OM)) on soil thermal properties. The research was conducted in greenhouses covered by three plastic types (normal PE - Greenhouse 1; UV+IR stabilized PE - Greenhouse 2; UV stabilized PE - Greenhouse 3) in the & Ccedil;ukurova region of Turkiye. Soil thermal diffusivity (D), a key heat transfer parameter that expresses the temperature gradient, was derived using soil temperature in the heat-amplitude equation. The means of the highest maximum soil temperatures at depths of 5, 20 and 30 cm were 54.3 degrees C (VCPE - Greenhouse 1), 46.2 degrees C (VCPE - Greenhouse 2) and 43.6 degrees C (BT - Greenhouse 2) for both years, respectively. The highest average values of D-5-30cm(-) were 65 cm(2) h(-1) with CO2 application, followed by 47 cm(2) h(-1) with BT, and 39.8 cm(2) h(-1) under OM+CO2. The D20-30cm was higher than those of the upper layer. Notably, the increase in heat emission towards the sub-soil layers under BT and OM was significant (P <0.05). OM, VCPE and BT treatments can be used successfully to increase the effectiveness of solarization. Additionally, Cv values increased in a linear relationship with the increase of soil water content. The thermal conductivity (K) increased as the soil water content approached field capacity and decreased when saturation levels were reached. This indicates that maintaining soil water content at saturation levels is not effective for solarization applications. 5