MAMATA CHHURIA AND MALAYA RANJAN MAHANANDA
Abstract
Fly ash, a byproduct of coal combustion in thermal power plants, holds promising potential as a sustainable soil amendment, especially in the agricultural sector. This study investigates the physico-chemical characterization of fly ash and evaluates its viability as an integrated nutrient supplement for rice (Oryza sativa) cultivation. A controlled pot experiment was conducted with four treatment levels of fly ash 10 g, 20 g and 30 g per pot alongside a control group. Photosynthetic pigments including chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids, were measured at five intervals (7th, 14th, 21st, 28th, and 35th day) to assess their effect on rice growth. Physico-chemical parameters of soil such as pH, electrical conductivity, organic matter, nitrogen and phosphates were analyzed post treatment. Morphological and elemental analysis of fly ash was conducted using Scanning Electron Microscopy, X-Ray Fluorescence and X-Ray Diffraction, while toxicity levels were assessed using the Toxicity Characteristic Leaching Procedure. The results revealed that photosynthetic pigments, particularly chlorophyll a, chlorophyll b and carotenoids, peaked in the 20 g treatment. One way ANOVA showed statistically significant differences (p <0.05) among the treatments. Soil tests indicated that parameters such as pH and nutrient content (except N, P and K) increased with higher fly ash doses. Correlation analysis demonstrated a negative relationship between pH and nitrogen content. XRF results confirmed that SiO2, Al2O3 and Fe2O3 were the dominant components in the fly ash, with Zn showing the highest mobility in TCLP tests. XRD analysis further confirmed the crystalline nature of the fly ash constituents.