Biopolymer‐Carboxymethyl Tamarind Kernel Gum‐Based Hydrogel Impregnated With Zeolite for Sustainable Soil Water Retention and Controlled Macronutrient Release

Abstract

In the agricultural sector, the application of bio‐based superabsorbent hydrogels offers significant potential for addressing challenges related to crop productivity and soil conditioning. In this study, carboxymethyl tamarind kernel gum (CMTKG), (poly)sodiumacrylate (PSA), itaconic acid (IA), and Zeolite (ZL) were utilized to synthesize novel CMTKG/PSA/IA/ZL and Potassium (K)‐loaded CMTKG/PSA/IA/ZL hydrogel composites via a free‐radical polymerization mechanism. A series of hydrogel composites was synthesized, and the most optimized formulation was selected for agricultural applications. Various experiments were performed to evaluate the effects of composition, sol–gel content, and swelling ratio at different pH levels. The retention rates of the hydrogel in water (~39°C) and soil were determined. The kinetics of K release were studied, and the release mechanism was elucidated using the best‐fit model. Additionally, the biodegradability of the hydrogel composites was evaluated. To assess real‐world application, a pot‐plantation study with Abelmoschus esculentus (okra) was conducted, demonstrating the hydrogel's potential to enhance soil properties and promote sustainable agriculture.