The direct effect of humic acid is to promote plant growth and increase crop yield. In addition to the direct effects of humic acid, there are physical, chemical, and biological effects.

Physical effect

Humic acid improves soil structure; prevents soil cracking and erosion; increases soil water holding capacity, improves cold resistance; makes soil color darker, which is conducive to solar energy absorption.

In soil humic acid helps improve water retention, increases soils over all structure, and help to maintain soil stability. Humic acids readily form salts with inorganic trace minerals in a form that can be more easily utilized by plants.

Humic acids promote vigor, disease resistance and root development in plants. These increases result in faster growth. The acids assist roots by increasing soil permeability, increasing water retention, reducing water evaporation, and promoting the growth of beneficial microbial colonies in the root zone. The creation of a healthy, microbial-active root zone environment creates stronger plants that uptake nutrients better.

Chemical action

Humic acid regulates soil pH; improves and optimizes plant nutrient and moisture absorption; increases soil buffer capacity; under alkaline conditions, it is a natural chelating agent (chelating with metal ions and promoting absorption by plants); It is rich in organic matter and minerals necessary for plant growth; it improves the solubility of organic fertilizers, reduces the loss of fertilizers; converts nutrients into a state that is easily absorbed by plants; strengthens the absorption of nitrogen by plants, and reduces the fixation of phosphorus. The elements such as nitrogen, phosphorus and potassium in the soil are stored in the soil, and the process of accelerating nutrient elements into the plant body can be accelerated, and the application effect of the inorganic fertilizer is improved. Therefore, humic acid is a plant nutrient element and a physiologically active substance. “Repository”.

Biological action

As all know humic substance is main fraction of soil organic matter,is results of humification of decaying plants body and leaves,humification is process of bioactivity of microorganism.

Main organism are protozoa, fungi, bacteria, arthropods, and beneficial nematodes,their working are decompose dead leaves and plants,extract nutrients and carbon,provide plants microelement like NPK in the form of plants usable.Thus microorganism is important to the soil fertility.

Humic acid stimulates the growth and reproduction of beneficial microorganisms in the soil; enhances the plant’s natural resistance to disease and insects.

The activities of beneficial soil microbes are crucial for the sustainability of any soil and plant growth. Humic acid stimulates microbial activity by providing the indigenous microbes with a carbon source for food, thus encouraging their growth and activity. Soil microbes are responsible for solubilizing vital nutrients such as phosphorus that can then be absorbed by the humic acid and in turn made available to the plant. Additionally, microbes are responsible for the continued development of humus in the soil as it continues to break down not fully decomposed organic matter. This in-situ production of humus continues to naturally add to the humic acid base and its benefits.