One, what is called humic acid
Humic acid is a mixture of natural organic macromolecular compounds. Widely present in nature, the proportion of humic acid in the soil is the largest, the soil humic acid is physicochemical heterogeneous complex molecular weight is polydisperse, the mixture is made of natural, high molecular weight, yellow to black, Amorphous, colloidal, fatty and aromatic organic polyelectrolyte composition, can not use a single chemical structure that.
Second, where is humic acid come from?
1, soil humic acid born, mainly plant under the action of microorganisms in the formation of a class of special macromolecular organic compounds mixture.
2, coal humic acid is a microbial decomposition and transformation of plants, but also after long-term geological and chemical effects, and the formation of a class of macromolecular organic compounds mixture.
Third, the structure and function of humic acid
Humic acid is a kind of natural organic weak acid, composed of fulvic acid, black fenic acid and brown acid three parts.
2, the composition of elements
Coal humic acid and soil organic matter in humic acid has a similar structure and nature of the main elements of humic acid carbon, hydrogen, oxygen, there are a small amount of nitrogen and sulfur, in addition to a variety of functional groups.
3, the role of humic acid
Most of the soil organic matter is humic acid, humic acid in the corrosive acid is the main body and its combination with metal ions, humic acid is the most active and most effective part of organic matter.
(1) the direct effect of humic acid
Promote plant growth and increase crop yields.
(2) indirect effect
A. Improve soil structure. B. Prevention of soil cracking and erosion. C. increase soil water holding capacity, improve cold resistance. D. make the soil color darker, is conducive to solar energy absorption. ② chemical effect. A. Adjust soil pH. B. Improve and optimize plant absorption of nutrients and water. C. increase soil buffer capacity. D. In alkaline conditions, is a natural chelating agent (chelated with metal ions, promote the absorption of 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. The nutrient element is converted into a state easily absorbed by the plant. H. can strengthen the plant nitrogen absorption, reduce phosphorus fixation, can penetrate the soil nitrogen and phosphorus and other elements, the protection box stored in the soil, and can accelerate the process of nutrient into the plant body, improve the application of inorganic fertilizer Therefore, humic acid is a "reserve" for plant nutrient elements and physiologically active substances.
③ biological effects
A. Stimulate the growth and reproduction of beneficial microorganisms in the soil. B. to improve the natural plant disease resistance, pest resistance.
Fourth, the commonly used humic acid species and characteristics
At present, humic acid commonly used as fertilizer is divided into lignite humic acid, weathered coal humic acid, peat (grassland humic acid).
1, lignite humic acid is the second stage of the process of coal (diagenesis) products, to the bitter coal phase has no humic acid, lignite humic acid in the general content of 1-85%, brown coal brown appearance, Black, according to the depth can be divided into
(1) soil lignite: the degree of coalification is shallow, low carbon content, humic acid content is higher, generally more than 40%.
(2) bright brown coal: a deeper degree of coal, carbon content is higher, humic acid content is low, generally 1-10%.
(3) dense lignite: between (1) and (2) between the general humic acid content of up to about 30%.
2, weathered coal humic acid that outcrop coal, commonly known as Johnson. Generally close to or exposed to the surface of lignite, bituminous coal, anthracite, through the air, sunshine, rain and snow, sand, frozen and other infiltration weathering, and the formation of the product. The humic acid produced by this process has become humic acid humic acid, also known as natural regenerated humic acid, humic acid content in weathered coal fluctuates greatly, ranging from 5-80%.
3, peat (peat, peat, etc.) humic acid
Peat is the initial stage of coal formation, also known as peat, Chinese peat humic acid content in 20-40%. Peat in the organic matter, is not decomposed by the plant waste and humic acid composition, the Chinese peat humic acid content of 20-40%.
Fifth, the development prospects of humic acid fertilizer
1, the whole process of green food, quality control technology system, the whole has reached the EU, the United States, Japan and other developed countries, food quality and safety standards, has been in international standards, but how to produce green food safety, the fundamental problem lies in how to overcome and To prevent the problem of soil pollution From the perspective of fertilization, we must adhere to the combination of organic and inorganic fertilizers, the use of humic acid fertilizer is the only choice, humic acid and fertilizer can be combined to achieve 1 +1> 2 integrated effect.