Soil Temperature and Evaporation Dynamics under Water Stress in Varying Soil Textures and Amendments

This study aimed to assess the effects of various textures and types of soil amendments on soil temperature dynamics and evaporation rates. The experiment was performed using Factorial Randomized Complete Block Design with two independent factors. The first factor was soil textures comprising sand, sandy loam, loam, silt loam, and clay, while the second was the type of soil amendments, including control, guano, and rice husk. Each soil type, amended and unamended, was placed in polybags, saturated with water to field capacity, and subjected to water stress conditions (without additional irrigation) for approximately 34 days. The magnitude of soil temperature fluctuations increased under water stress relative to pre-stress conditions. The highest soil temperature during the day was produced by sandy textures, while at night, the temperature was slightly greater in silt loam and clay. Generally, higher sand fraction correlates with greater temperature during the day and lower at night. The application of soil amendments to all soil textures can produce lower soil temperature during the day and retain heat at night, making soil temperature warmer than the control. Based on the experiment, the highest cumulative evaporation was observed in silt loam soil and samples without the addition of soil amendments. Moreover, extended water stress led to a smaller loss of water by evaporation. To help manage water stress, future studies need to assess the effects of soil amendments on moisture thresholds and the applications in irrigation management.