Effects of Carboxymethylcelluloses On Some Hydraulic Properties of Sandy Soil.

The property of hydrophilic polymers capable absorbing huge volumes of water led to many practical applications of these new materials in arid regions for improving water retention in sandy soils. The effects of four carboxymethylcelluloses (CMC), mixed at various rates with a sandy soil, on the water-holding capacity and hydraulic conductivity (K_S) of the sandy soil when leached with distilled water (simulating rain), tap water, and saline waters were evaluated. The maximum water absorption of the CMCs ranged between 80 and 100 kg kg^-1 of polymer, however, the absorbent swelling capacity decreased significantly with increasing salt concentration in the solution. The water absorption capacity of the CMCs decreased significantly when incorporated in the sandy soil compared to that of the absorbent alone. Application of CMC increased significantly the available water content up to 3 ±0.5 times. All soils treated with CMCs showed a significant lower in K_S compared to the control soil. And, K_S was found increased with increasing the salt concentration in the leaching solution. This understanding of the characteristics of the absorbents and the interactions among absorbents, soil, and irrigation water quality would be of help in water management in sandy soil.