Effect of Temperature on the Soil-Water Content-Suction Relationship

Relationship between soil-water content and suction in Patharchatta sandy loam of Pantnagar was studied at 10, 20, 30 and 45°C. At a particular suction the samples kept at low temperature retained more water than those at higher temperatures. For example, at 1/3 bar suction the amount of water retained was about 0.232, 0.222, 0.216, 0.205 cm³ cm⁻³ at 10, 20, 30 and 45°C, respectively. Matric suction decreased with increase in temperature for all water contents. When θ = 0.34 cm³ cm⁻³, the matric suction at 10°C was 1.12, 1.30 and 1.4 times that at 20, 30 and 45°C, respectively. This dependence of matric suction on temperature could not be explained on the basis of surface tension effect.