Superabsorbent nanocomposite based on maize bran with integration of water-retaining and slow-release NPK fertilizer

A novel fertilizer-integrated superabsorbent nanocomposite based on maize bran (MB), acrylic acid (AA), and acrylamide (AAm) was synthesized in an aqueous solution containing montmorillonite (MMT) and NPK fertilizer compound. FTIR spectra indicated that hydroxyl group of the starch molecules in MB composition has participated in grafting reaction with acrylate-based monomers. The swelling behavior of the synthesized hydrogels in different salt and pH solutions was evaluated. Also, the N,N'-methylenebisacrylamide (MBA) and MMT contents were systematically optimized to obtain a highest swelling capacity. Fertilizer release assessments on the NPK-loaded superabsorbent nanocomposite confirmed the effective role of MMT nanolayers in slow-release property of the prepared formulation. Also, the prepared fertilizer formulation exhibited good water retention capacity in soil. As a result, this eco-friendly and economical product can effectively reduce fertilizer loss, improve water utilization efficiency, and prolong irrigation cycles which are benefit for agricultural applications, especially in drought-prone environments.