Potential use of polyacrylamide for improving availability of soil moisture and plant production in sandy soil

Two pot experiments were carried out under greenhouse conditions to examine the effect of applied forms (granular , soluble in water) and additive percentages (0.01 , 0.02 , and 0.03 % by weight) of Polyacrylamide (P A M ) to light-textured soil in order to changing soil water behavior and plant production .The obtained results showed that the addition of polyacrylamide to sandy soil under different levels and forms of application reduced evaporation from the soil surface .The results showed a low rate of water evaporation with values ranged between 11.62% and 19.3% of control under both treatments of (PAM) in granular, and soluble forms at 0.03% addition level, respectively and thus increased the water stored in the soil. The addition of polyacrylamide raised the moisture content at saturation (0.001 bars) and field capacity (0.33 bar) compared to the control and the differences increased with increasing PAM concentration, especially under soluble form. All levels and forms of PAM had no clear effect on the retention of water in the soil at wilting point(15 bar). Available water that ranged between 0.33 bar and 15 bar increased 1.92 times of control under the less influential treatment (soluble, 0.01%) and to 3.12 times under the highest impact treatment (soluble, 0.03%).Under all treatments the fresh and dry weights of (Eruca Sativa) plants increased compared with the control treatment. The results indicated that the dry weight increased 1.49 times the control under the highest impact treatment (soluble, 0.03%).Water use efficiency increased under all treatments compared to the control, especially at high levels of PAM at both forms. The results indicated a more water use efficiency than the control under levels of application 0.03% for both forms. These results may indicate that PAM can enhance rates of nutrient absorption and improve the growing conditions of plant roots.