Ghonwa Khaddour ^(1)*

(1) .General commission for scientific agricultural research, Latakia center/ Syria.

(*Corresponding author: Ghonwa Khaddour, E-Mail: ghonwakhaddour@hotmail.com, Phone: 0934797446).

                Received:8/10/2024                        Accepted:11/12/2024                                                         

Abstract: 

This research was carried out at the Agricultural Scientific Research Center in Lattakia Governorate during the years 2020-2022, in order to estimate the moisture tension curve for soils taken from two sites in the governorate: Al-Sanobar Station-sandy clay soil, and Buqa Center-clay soil. The moisture tension curve represents the relationship between the amount of water and water pressure in the soil, and this curve is considered one of the most important hydrodynamic properties that characterize soil and is difficult to determine. For this purpose, a simplified device that works according to the principle of hanged water column was designed and implemented so that it allows applying pressure to the soil water and calculating the amount of water for cylindrical samples with dimensions (r × h=1.2 × 2cm). The experiment was conducted following the drying path first, then the wetting path by applying pressure values within the range 0-3 kilopascals, at a rate of 3 replicates for each site. The results showed that clay soils have higher water holding capacity and moisture tension compared to sandy clay soils, where air entry value for clay samples was 0.6 kPa compared to 0.5 kPa for sandy clay samples, while the minimum degree of saturation in the drying path was (37.1, 45.3, 39.2%) for clay samples compared to (38.9, 35.3, 33.9%) for sandy clay samples. On the other hand, the maximum degree of saturation in the wetting path was (90.6, 90.2, 91.4%) for clay samples compared to (84.7, 83.2, 82.2%) for sandy clay samples.

Keywords:, Soil water retention curve, sandy and clayey soils, wetting and drying.

Full paper in Arabic: pdf