An efficient strategy of managing irrigation water based on formulating highly absorbent polymer–inorganic clay composites

The management of irrigation water presents a great challenge for the agriculture field. In view of increasing soil water-holding capacity and increasing water-use efficiency, an efficient strategy of managing irrigation water based on formulating highly absorbent polymer–inorganic clay composite (polyacrylic acid–layered double hydroxide; PAA–LDH) was offered. The PAA–LDH composite was synthesized by an incorporation/in situ polymerization technique. Scanning electron microscopy, X-ray analysis and infrared spectroscopy were used to confirm the composite structure. The thermal gravimetric analysis was applied to investigate the polymer thermal stability after the composite formation. The irrigation experiments were conducted in a wooden soil box with a transparent plexiglas side by using a subsurface drip irrigation system. The X-ray patterns and infrared spectra confirmed the incorporation of acrylic acid monomer (AA) into the gallery of LDH. The SEM images emphasized the composite structure of PAA–LDH and indicated its ability to absorb and keep water. The stability of PAA was promoted against the thermal decomposition after the composite formation. The composite structure of PAA–LDH worked as water barrier and secondary water source during the irrigation process. The soil moisture distribution patterns were enhanced after the application of PAA–LDH composites as a soil conditioner.