Correlation of Permeability with Gypsum Percentage, Water Salinity and Application Technique

Abstract A laboratory experiment was conducted in the laboratories of the College of Agriculture, University of Anbar. Three levels of gypsum soil (9, 19.7, and 46.3%) were collected and packed into transparent columns 40 cm long and 30 cm long. These columns were filled with a bulk density approximately equal to the field density. Three levels of saline water (2, 4, and 8 dSm −1 ) were also added. Water levels were added in continuous and intermittent flows. Permeability was measured using the relationship between cumulative effluent and the distance of the wetting front advance. The results showed that permeability increased with increasing gypsum content, with the highest value reaching 3.89 cm min −2/1 and the lowest value reaching 2.93 cm min −2/1 for gypsum contents of 46.3 and 9%, respectively. The highest value of the salt effect was 2.94 cm min −2/1 and the lowest value was 2.46 cm min −2/1 for the salinity level of 2 and 8 dS m −1 , respectively. The highest value of the effect of the addition method was with the continuous addition method, reaching 2.98 cm min −2/1 , and 2.93 cm min −2/1 with the intermittent addition method at the salinity level of 8 dS m −1 .