Phosphorus (P) is an essential nutrient for plant growth and is often the limiting nutrient in agricultural ecosystems owing to its low availability in soils, especially as free P, which is hampered because of the formation of poorly soluble complex with other ions (like Fe, Al and Ca) in the soil. Humic substances are stable complex organic molecules formed by degradation of litters in the soil. Humic acid (HA) in the soil adsorbs to plant roots and helps in absorption of water and nutrients resulting in enhanced yield. HA also decreases the formation of metal complexes with P, thus, making it freely available to the plants. Therefore, studies were conducted by mixing HA with single super phosphate (SSP) and applied as phosphate fertilizer to the plants. The combination of HA with SSP has increased the available phosphate in soil, and the uptake of P by the plants up to 45%, which resulted in enhanced crop yield . This also found to reduce the application of phosphate by 30%.
