Humic acid is a natural mixture of organic macromolecules. Widely exist in nature, the proportion of soil humic acid is the largest, soil humic acid is a complex mixture on the physical chemistry of heterogeneous molecular weight is more dispersed, the mixture is made from natural, high molecular weight, yellow to black, amorphous, gel, with fat and aromaticity of organic polyelectrolyte, cannot be expressed in a single chemical structural formula.
Where does humic acid come from
1. Soil humic acid is born with a mixture of a special kind of large molecular organic compound that plants form under the action of microorganisms.
2. Coal humic acid is a mixture of a group of large molecular organic compounds formed by the process of decomposition and conversion of microorganisms and long-term geological chemistry.
Function and function of humic acid structure
Humic acid is a kind of natural organic weak acid, which consists of three parts: yellow humic acid, black humic acid and brown humic acid.
2. Element composition
Coal humic acid and humic acid in soil organic matter with similar structure and properties of humic acid of main elements carbon, hydrogen, oxygen, and a small amount of nitrogen and sulfur, in addition, there are a variety of functional groups.
3. The role of humic acid
In the soil organic matter, humic acid is the most common. Humic acid in the corrosive quality is the main body and the salt which is combined with metal ions. Humic acid is the most active and effective part of organic matter.
(1) the direct effect of humic acid
Promote plant growth and crop yield.
(2) indirect action
A. improve soil structure. B. Soil cracking and erosion control. C. Increase soil water holding capacity and improve cold resistance. D. make the soil dark and beneficial to solar energy absorption. Chemistry. A. adjust the PH of the soil. B. improve and optimize plants' absorption of nutrients and water. C. Increase soil buffer capacity. D. Under alkaline conditions, it is a natural chelating agent (with metal ion chelation, the promotion period is absorbed by plants). E. rich in organic matter and minerals necessary for plant growth. F. improve the solubility of organic fertilizers and reduce the loss of fertilizer. G. Transform the nutrient elements into a state easily absorbed by plants. H. can strengthen plants on the absorption of nitrogen, reduce the phosphorus fixation, can put into the NPK elements, such as soil protection box storage in soil, and can accelerate the process of nutrient elements into the plant, improve the effect of the application of inorganic fertilizer, say so, humic acid is a plant nutrition elements and physiological active substances "reserve".
A. stimulate the growth and reproduction of beneficial microorganisms in the soil. B. improve plant natural disease resistance and insect resistance.
The types and properties of humic acid are commonly used
At present, humic acid used in fertilizer is divided into lignite humic acid, weathering coal humic acid and peat (humic acid).
1, lignite humic acid is the second stage in the process of coal (rock) of the product, to bituminous stage has not including humic acid, lignite humic acid content in 1-85% commonly, appearance of lignite is brown, a few in black, can be divided by degree of depth
(1) soil-like lignite: the degree of coal is relatively shallow, the carbon content is low, the humic acid content is higher, generally more than 40 %.
(2) bright lignite: the degree of coal is deeper, the carbon content is higher, the humic acid content is lower, generally 1-10%.
(3) dense lignite: between (1) and (2), the average humic acid content can reach about 30%.
2. Weathering coal humic acid is known as the coal. General approach or exposure to the surface of lignite, bituminous coal, anthracite, through the air, sunshine, rain and snow, wind, sand, freezing and other infiltration of weathering, and formed products. The humic acid produced from this process is the humic acid of weathered coal, also known as natural regeneration humic acid. In weathering coal, humic acid content fluctuates a lot and can range from 5 to 80 percent.
3. Peat (peat, turf, etc.) humic acid
Peat is the initial stage of coal, also called peat, and the humic acid content in China's peat is 20 to 40 %. The organic matter in peat is composed of undecomposed plant waste and humic acid. The content of humic acid in China's peat is 20 to 40 %.