Utilizing Hydrogel for Improving Irrigation Management

Abstract

The major goal of the present day agriculture is to maximize land and water productivity without threatening the environment and the natural resources. Irrigation process is improved by using hydrogels. This research demonstrated the possibility of utilizing superabsorbent polymer obtained from baby diapers, to increase water retention in soil, for better management of water used in irrigation. After separation, recovery and cleaning of the recycled hydrogel, experimental parametric study was performed to investigate the swelling ability, and deswelling behavior and kinetics, and investigate parameters including the effects of temperature, saline solution, and pH on the recycled hydrogel performance. Red clay soil was mixed with different percentages of hydrogel in order to investigate water retention ability in soil improved with hydrogel from waste. The recycled hydrogel had typical kinetic behavior, where it increased slowly with time, until it approached an equilibrium state after about 100 min. The equilibrium swelling capacity reached a maximum value of 235 g water/g hydrogel. The swelling capacity increased with temperature, while it decreased with increasing pH or salt concentration in saline solution. With samples of soil and hydrogel, the addition of the recycled hydrogel decreased the water loss by infiltration. Hydrogel was used in an agricultural experiment through the preparation five of treatments of soil with different percentages of hydrogel, along with control. The behavior of tomato seedlings grown in different percentages of hydrogel and control length, number of leaves and girth as well as the amount of water losses by infiltration from each replicate in each treatment over 30 days. The ratio of 2%,3% of hydrogel was the best in all samples in terms of the efficiency of growth and the reduction of water quantities of irrigation and prevention of infiltration. The treatments 4% and 5% were less efficient growth, but it has able to resist the conditions of drought reached 21days, but they were able to resist dehydration due to contains hydrogel. Keywords: Hydrogel, Irrigation, Swelling, Superabsorbent polymer, Agriculture.