Effect of Gravel-Sand Mole Drains on Soil Electrical Conductivity and Exchanged Sodium Percentage

A field study was conducted to evaluate the effects of the mole drains in the corn crop (zea mayes L.) field during the season of 2019; this study was carried out at the Agricultural research station, University of Basrah, where the soil was silty clay loam. The results showed that the treatments of mole drains filled with gravel and sand mixture (S+G) and filled with gravel and sand layers (S/G) affected the decrease of the electrical conductivity (EC), and the exchanged sodium percentage (ESP) compared to W.M. treatment. The S/G drain gave lower values compared to the S+G drain. As well as, the values of EC decreased by the increase of the depth of the mole drain. Also, the treatments of mole drains distances of 2 m decreased the values of EC and ESP compared to the distance of 4 m. The S/G with depth of 60 cm and distance of 2m gave the lower values of EC and ESP, while the W.M. treatment gave higher values. Soil depths of 0-10 and 10-20 cm reached the lower values of EC and ESP; however depths of 50-60 cm gave the higher values. The treatment of S/G, with mole drain depth of 50 cm, and soil depth of 20-30 cm gave a lower value of EC; while, S+G, with mole drain depth of 50 cm, and soil depth of 50-60 cm gave a higher value. Finally, the ESP was decreased in the end of the growing season compared to the middle of the season.