Characterization of Soil Nutrients by FTIR: Application to the Analysis of Micronutrients Changes in Soil affected by Food Crops

Fourier Transform Infrared Spectroscopy (FTIR) has emerged as a powerful and non-destructive analytical technique for characterizing chemical and structural properties of soil. This study aims to apply FTIR spectroscopy to evaluate the changes in soil micronutrients influenced by food crop cultivation. The research focuses on identifying functional groups and molecular bonds related to essential micronutrients like iron (Fe), copper (Cu), manganese (Mn), zinc (Zn) and boron (B), and examining their variations before and after cultivation of selected food crops. Soil samples were collected from cultivated plots at different growth stages and compared with uncultivated control samples. FTIR spectra were analyzed within the mid-infrared region (4000–400 cm⁻¹), enabling the detection of shifts in absorption peaks associated with organic matter, clay minerals, metal oxides, and nutrient complexes. Significant spectral changes were observed, particularly in regions linked to metal-ligand interactions and phosphate, carbonate, and hydroxyl functional groups. These variations suggest active nutrient mobilization, uptake, and transformation processes mediated by root activity and microbial interactions in the rhizosphere. The findings also highlight how specific food crops can influence micronutrient availability and redistribution in soil, thereby offering insights into sustainable soil fertility management. Overall, this study demonstrates the effectiveness of FTIR as a rapid and environmentally friendly tool for monitoring micronutrient dynamics in agricultural soils. The outcomes provide valuable baseline data to guide soil amendment practices, optimize fertilizer input, and support precision agriculture strategies for enhancing soil health and crop productivity. Further integration with complementary techniques could strengthen nutrient profiling in future soil research.