Biodegradable CMC/Zn/Ca/Cu cross-linked novel superabsorbent hydrogel beads for plant pathogen prevention and agricultural application

Abstract

A multi-nutrient biodegradable, biocompatible carboxymethyl cellulose-based zinc, calcium, and copper cross-linked hydrogel beads (CMC@CC) was prepared through the ionic cross-linking method. Further, nitrate was loaded in CMC@CC to obtain NCMC@CC. At optimized conditions, CMC@CC shows a ~915% equilibrium swelling ratio in distilled water. The swelling kinetics of hydrogel beads in water at optimized conditions followed Fickian diffusion and second order kinetics. NCMC@CC exhibits a slow-release profile of nitrate in water and was better fitted by the Korsmeyer-Peppas model and the release of nitrate was controlled by diffusion mechanism. The functional efficacy of the NCMC@CC nanocomposite beads were investigated by studying the growth pattern of tomato plants (Solanum lycopersicum L.) in soil. Application of NCMC@CC showed significant growth over control specimens. In vitro antibacterial study of prepared hydrogel beads against Ralstonia solanacearum F1C1, a plant pathogen responsible for wilt disease in tomato, reveals that prepared hydrogel beads also poses great bactericidal efficacy. This dual functional hydrogel beads could reduce the simultaneous application of pesticides alongside fertilizers for plant growth thus promoting sustainability.