Humic acid is an organic compound resulting from the biological decomposition of dead organic matter, including plant and animal residues. This group of aromatic and aliphatic compounds appears dark brown to black and has a chemical formula of C???H???O??N?S, with a high molecular weight ranging from 100,000 to 1,000,000 Daltons. Its structure features carbon rings connected to functional groups like COOH, OH, C=O, NH?, and S?. The composition includes approximately 40% oxygen, 3% nitrogen, 5% hydrogen, 50% carbon, and 1% sulfur and phosphorus, highlighting its complex nature and vital role in soil health and nutrient cycling.

Humic acid is extracted from decomposed organic matter through the action of microorganisms, which indicate the decomposition process by changes in color, a reduction in mass, and the disappearance of odor. Once decomposition is complete, a specific weight of the organic material is treated with strong basic solutions, such as NaOH or KOH, at a ratio of 10:1. This process yields various organic acids, including humic acid, fulvic acid, and human. Following extraction, the pH of the solution is adjusted to 1 using hydrochloric acid (HCl), resulting in the precipitation of humic acid while fulvic acid remains dissolved. The resulting humic acid can then be purified through filtration and centrifugation to remove impurities. Once purified, it can be dried and stored for use in agricultural and environmental applications.

Humic acid is a colloidal substance that retains water and contains a small percentage of nutrients that are gradually released in forms absorbable by plants. While it is not a fertilizer on its own, it significantly enhances soil quality and plant growth. Humic acid helps break down soil, particularly clay, improving aeration and facilitating mineral movement and root penetration. In sandy soils, it promotes cohesion and enhances water and nutrient retention through cation exchange. Its negative charge attracts positively charged nutrients, allowing them to adhere to soil particles and become more readily available to plants. Key nutrients provided include nitrogen, iron, zinc, and copper.

Humic acid reduces soil salt levels by breaking the bonds between ions, thereby lowering their toxicity. It optimizes soil pH between 5.5 and 7.5, enhancing nutrient availability for plants. Additionally, it fosters a healthy environment for soil microorganisms, which are essential for decomposing organic matter and maintaining nutrient cycles, ultimately boosting soil fertility and biodiversity. In conclusion, humic acid has significant applications, with ongoing research exploring its potential to adsorb pollutants and its overall biological effectiveness. 

Humic acid has a modern environmental impact as an organic, non-toxic, and biodegradable product that minimizes nutrient leakage into groundwater, thus reducing pollution. Its commercial value enhances the global economy while offering sustainable solutions for soil rehabilitation and environmental restoration. This article seeks to raise awareness in the scientific community about the significant potential of humic acid production technologies and their role in sustainable development.