1. Improve soil water and fertilizer retention capacity
Humic acid has hydrophilic colloids and can absorb a large amount of water, so it is very good at improving soil moisture retention. Humic acid can act as a soil penetrant, reducing the transpiration of soil water, thereby supplying more useful water to the soil. For soil with weak fertilizer retention, adding humic acid substances can not only increase the nutrient mass fraction in the soil, but also improve the soil’s aggregate structure, thereby improving the fertilizer retention ability.
2. Improve the physical properties of soil
Humic acid is first coated on the surface of mineral soil particles in the form of a film in the soil. Because of its colloidal properties, its cohesive force and adhesion force are greater than those of sand particles. After being applied to the soil, it can increase the stickiness of the sand particles, which is effective. Promote the formation of aggregate structure.
Humic acid is soft, flocculent, and porous. Its cohesive force is nearly 10 times smaller than that of clay particles, and its cohesive force is half that of clay particles. Therefore, after clay particles are coated, it is easy to form scattered aggregates, making the soil looser and more No more clumping.
Humic acid can tighten sandy soil and loosen clay, thereby improving the water retention, water permeability and air permeability of the soil, making it more suitable for agricultural cultivation needs.
3. Adjust soil pH
Humic acid has a strong ability to buffer acid-base changes. In this process, it can form an acid-base buffer to adjust acidity and alkali.
4. Absorb heavy metals from soil and reduce damage to crops and soil caused by heavy metals.
If agricultural products were used too much in the past, some heavy metals would be added to the soil in the process. In addition, due to environmental pollution in recent years, heavy metals in the soil will also be added. Mineral humic acid has a solidifying effect on heavy metals. This can reduce the damage of heavy metals to crops and soil.
5. Control soil heat
It has a certain impact on the thermal state of the soil, mainly because humus is a dark substance, and its presence can significantly deepen the color of the soil, thereby regulating the heat absorption of the soil. At the same time, the heat capacity of humus is larger than that of air and minerals, but smaller than that of water, and its thermal conductivity is in the middle. Therefore, under the same sunlight conditions, soil with a high mass fraction of humus will have a relatively high soil temperature and a small change, which is conducive to low-temperature sowing of crops. Better growth.
6. Promote soil microbial activity
The energy and nutrients required for the life activities of soil microorganisms come directly or indirectly from soil organic matter. Humus plays a role as the main form of soil organic matter. The main component of humus is humic acid. Therefore, the use of humic acid to regulate the acid-base reaction of the soil can promote beneficial changes in the physical structure of the soil, provide guarantee for the life activities of microorganisms, and promote Soil microbial activity, increasing the number of beneficial soil microorganisms and enhancing the activity of soil enzymes.