Abstract
Aim: The current study aimed to synthesize nanosilica from maize stalks at various calcination temperatures and to evaluate silicon release pattern in soil. Methodology: Nanosilica was synthesized by sol-gel method through thermal decomposition (500-700 oC) of maize stalks and evaluated for silicon release with varied levels (0, 5, 10, 15, 20, 30, 40 mg kg-1) through an incubation experiment and the data obtained was fitted in various kinetic models. Results: Nanosilica synthesized from maize stalks calcined at 700 oC showed spherical morphology with little agglomeration, amorphous nature and higher purity than the products obtained at 500 oC and 600 oC. Incubation experiment revealed that application of nanosilica at 40 mg kg-1 increased the available silicon upto 60 days with slight decrease at 80 days. The silicon release pattern from nanosilica was fitted in kinetic equations and observed that pseudo-second order equation describes the silicon release in a better way than other models. Interpretation: The present study showed a sustainable approach to convert maize stalks into valuable nanosilica, addressing the pressing issue of agri-waste management. The nanosilica synthesized from maize stalks calcined at 700oC exhibited promising characteristics and good silicon release pattern which can be alternatively used as a fertilizer source in agriculture. Key words: Agglomeration, Available silicon, Kinetics, Maize stalks, Nanosilica