Humic acid plays an important role in soil

Most of the essential nutrients in the plant growth process are obtained from water-soluble fertilizers, which can meet the nutrients needed by your plants in the process of growth. The following summarizes the synergistic effect of humic acid on various fertilizers and its important role in soil:

1. The synergistic effect on nitrogen fertilizer

Nitrogen fertilizers are mostly carbonic acid and urea. Ammonium nitrogen is unstable and volatile. After mixing with humic acid fertilizers, humic acid contains functional groups such as carboxyl and phenolic carboxyl groups, and has strong ion exchange and adsorption capabilities. Reduce the loss of ammonium nitrogen. Urea is an amide nitrogen fertilizer, and the nitrogen contained in it needs to be decomposed and converted into ammonium carbonate by the urease secreted by urea bacteria before it can be absorbed by plants. If urea is applied to calcareous soil, the ammonium bicarbonate produced by the decomposition of urea will also be volatilized and lost due to alkalinity, which is one of the reasons why the nitrogen utilization rate of urea fertilizer is not high. Adding humic acid to urea has obvious synergistic effect on urea. One is to inhibit the activity of urease, slow down the decomposition of urea, and reduce volatilization; the other is that humic acid can form complexes with urea, and gradually decompose to release nitrogen, which prolongs the fertilizer effect of urea, and the biological activity of humic acid can promote plant root system. Development and nitrogen metabolism in the body, promote nitrogen absorption.

2. The synergistic effect on phosphate fertilizer

When the quick-acting phosphorus fertilizer is applied to the soil, the soluble phosphorus is easily fixed by the soil. In acidic soil, phosphorus is mainly fixed by free iron and aluminum ions; Even for ineffective phosphorus, the utilization rate of phosphorus in the current season is only 10-20%. After the addition of humic acid fertilizers, it can inhibit the fixation of water-soluble phosphorus in the soil, slow down the conversion of quick-acting phosphorus to late-acting and ineffective state, and the nitro humic acid in slurry will increase the moving distance of phosphorus in the soil, and promote the root system to adjust phosphorus. Absorption.

3. The synergistic effect on potassium fertilizer

Humic acid contains functional groups that can absorb and store potassium ions, which can not only prevent it from losing with water in sandy soil and leaching soil, but also prevent the fixation of potassium in cohesive soil. Some parts of humic acid are low-molecular humic acid such as fulvic acid, which can dissolve minerals such as potassium-containing silicate and potassium feldspar, which can slowly decompose them, increase the release of potassium, and increase the content of available potassium.

4. The synergistic effect on micro-fertilizers

There is a considerable amount of trace element reserves in the soil, but the effective part that can be absorbed by plants is too little. Humic acid and insoluble trace elements can undergo a complex reaction to form a humic acid trace element complex with good solubility and easy absorption by plants, which is conducive to root absorption or leaf absorption, and promotes plants to absorb trace elements from the roots Transferred to the aboveground part, spreading from some leaves to other leaves.

The indirect effect of humic acid on soil can be divided into physical effect and chemical effect.

Physical effect

1) Improve soil structure

2) Prevent soil cracking and soil erosion.

3) Increase soil water holding capacity and improve drought resistance

4) Darken the color of the soil, which is conducive to the absorption of solar energy

Chemical action

1) Adjust the pH of the soil.

2) Improve and optimize plant uptake of nutrients and water

3) Acts as a natural chelating agent with metal ions to promote its root absorption under alkaline conditions.

4) Rich in organic matter and minerals necessary for plant growth.

5) Keep soluble inorganic fertilizers in the root zone, reducing their loss.

6) Improve soil cation exchange capacity.

7) Transform nutrients into a state that can be easily absorbed by plants.

8) Enhance the uptake of nitrogen by plants.

9) Reduce the chance of phosphorus reacting with Ca, Fe, Mg, and Al, so that phosphorus exists in a state that is beneficial to plant growth.

10) It helps CO2 to be released from soil calcium carbonate and can be used by photosynthesis.

11) Helps reduce plant chlorosis caused by trace elements.

12) Reduce the availability of toxic substances in soil.

13) Biological effects.

14) Stimulate the growth and reproduction of beneficial microorganisms in the soil.

15) Improve the natural resistance of plants and the ability of insect pests.

The humic acid contained in peat, lignite, and weathered coal is called coal humic acid. They have similar structures and properties to soil humic acid in soil organic matter, and have many similarities in their impact on soil and crops.