The Function of Fulvic Acid in Soil Improvement
Fulvic acid can improve the soil's physical characteristics and soil aggregate structure. As a humus substance, fulvic acid can affect the properties of soil and promote the formation of a more stable aggregate structure. It can also increase the aggregate content of 0.25mm in soil by 10-20% and the organic matter content by 10%, which can maintain soil moisture and increase soil aeration and benefit the growth of crops.
Fulvic acid can enhance the water retention of soil. Fulvic acid is a hydrophilic colloid with a strong water absorption capacity and the maximum water absorption exceeds 500%. The weight of water absorbed from the saturated atmosphere can be more than twice its own weight, much larger than the general mineral colloid. Fulvic acid inhibited the transpiration of crops, slowed down the rate of soil water consumption, and increased the soil water content.
Fulvic acid can enhance the nutrient-preserving capability of soil. Fulvic acid is a kind of organic acid. It not only increases the mineral part dissolved in the soil and provides soil nutrients, but also increases the effectiveness of nutrients through complexation. As an organic colloid, fulvic acid has both positive and negative charges, it can adsorb positive ions and negative ions so that we can save these nutrients in the soil and improve the utilization rate of fertilizer. This function is particularly important in the sandy soil area.
Fulvic acid can adjust the PH of the soil solution. Fulvic acid and fulvic salts transform each other to form a buffer system that regulates the PH of soil solutions.
Fulvic acid can reduce soil salinity. The colloid structure formed by fulvic acid chelates metal cation in the soil and its porosity can absorb the ions or molecules in the soil solution and reduce the concentration of salt in the soil solution.
Fulvic acid contains a variety of oxygen-containing functional groups, which determine their physiological activities, thus playing a regulatory role in life activities. It can promote the growth and reproduction of beneficial bacteria, and inhibit the number of harmful microorganisms. The Carboxyl and phenolic hydroxyl groups in fulvic acid have a certain inhibitory effect on the virus.