The organic fraction, also known as Soil Organic Matter (SOM) is a diverse and complex mixture of organic substances, formed through the interplay between various factors such as plant and microbial inputs, the nature of the parent material, and the climatic conditions . Humic substances (HSs) are major components of SOM formed from the decomposition of plant and microbial residues. They are complex mixtures composed of numerous molecules, many of which contain an aromatic nucleus with phenolic and carboxylic groups as substituents . HSs contain two main fractions: humic acid (HA) and fulvic acid (FA), which differ in their chemical composition, solubility, molecular weight, color, and biological activity. HA is a larger, darker, and less soluble molecular system that mainly enhances soil structure and water retention, while FA is a smaller, lighter, and more soluble molecular system with a higher concentration of carboxylic groups that improves nutrient absorption and bioavailability .