Humic acids widely used in Agriculture as soil conditioners, chemical fertilizer catalysts, plant growth regulators. 1. Promote Fertilizer, Increase Utilization of Nitrogen, Phosphorus, Potassium, and Nutrition. For Nitrogen: Since Humic Acid has a salt exchange capacity many times higher than soil, it can adsorb a large number of ammonium ions to reduce the loss. Besides, It has a good inhibitory effect on urea and nitrifying bacteria, and can greatly increase urea. For Phosphorus: It can react with the fixed phosphate fertilizer to convert it into phosphorus. It has a protective effect on phosphorus, can improve the utilization rate of phosphate fertilizer. It can also improve the mobility of phosphorus, which is DAP/MAP, etc… For Potassium: HA has a strong adsorption effect on K+, which can reduce the loss. Besides, It also has a dissolution effect on Potassium-containing minerals such as Potassium Silicate and Potassium Feldspar, thereby increasing the effective potassium content in the soil. 2. Humic Acid can improve Soil Structure, Regulate Soil Ph, Regulate Photothermal, Microbial growth, and Reduce pollution. Adjusting the PH of the Soil: Since HA is a multi-weak acid, it has a strong buffering property, so it can play a role in mediating the pH of the soil, and then convert nutrients and trace elements into a form that can be absorbed by plants. Dimming Heat: Since Humic Acid has a deep black color, it is equivalent to laying a black mulch on the soil after being applied to the soil, which improves the photothermal performance and increases the ground temperature. Improve Bacterial Activity: In the soil of the compacted soil, Humic Acid can interact with beneficial bacteria to make the soil a soft structure as well as promote the absorption of nutrition. The colloidal properties of HA have good adhesiveness, which is beneficial to the formation of the soil aggregate structure. In acidic soil environments, Humic Acid can react with heavy metals to reduce metal pollution. Besides, HA itself contains Auxin that promotes cell wall division, plant growth as well as increases sugar, nutrients, and biomass. Last but not least, HA is an effective component to stimulate Crop Growth, Promote Rooting, and Enhance Photosynthesis. 3. Fertilizers, Crops, and Soils always interact with each other. If the soil has high organic content and a good agglomerate structure, then the fertilizer is more helpful. If the soil is poor, the fertilizer is harmful as well. Therefore, we must apply fertilizer and the organic matter rationally to maintain the extension and development of the root system, which is beneficial to growth. 4. Humic Acid helps the Degradation of Residual Pesticides and promotes the growth of microorganisms in the soil.