Why can humic acid improve the stress resistance of crops

Humic acid is a kind of natural mixture of organic macromolecular compounds, which widely exists in nature. Due to its unique physiological functions, humic acid has been widely used in agricultural production in recent years. In addition to improving soil, improving fertilizer efficiency, promoting crop growth and other aspects, its role in plant stress resistance has been paid more and more attention.

Plant is an open system, living in the natural environment, will inevitably be damaged by the bad environment. Generally, we call the environment that causes harm to plants as adversity (or stress), which can be divided into the following categories:

When these stresses occur, plants will produce a series of changes, such as drought will lead to leaf and tender stem wilting; flooding will make leaves yellow, dry, root browning and even rot; under high temperature, leaves will become brown, dead spots and bark cracking; pathogenic bacteria will infect leaves and appear disease spots. In light, it affects the growth and development, yield and quality of plants, and even directly leads to its death in severe cases.

Different from people and animals, plants can't escape no matter what danger they encounter. Since they can't run away, plants can only take the second place and develop the ability of "being beaten". This is the origin of plant stress resistance.

For example, under drought conditions, plants can maintain water balance by controlling the opening and closing of stomata of leaves; under high salinity environment stress, a large amount of salt solution can be prevented from entering the plant by improving the permeability of cell membrane; even when suffering from diseases and insect pests, some plants can produce chemical substances to resist or attract natural enemies of diseases and insect pests to eliminate them.



Generally speaking, the stress resistance of plants is relatively small at the peak of growth, and increases after dormancy; the stress resistance is strong in vegetative growth period, and weak in flowering stage. But if the adversity exceeds its tolerance, the plant is doomed. However, once the adversity appears, we can't change it, but if we can improve the stress resistance of plants, it may be a good way!

The role of humic acid in various adversity

Plant drought stress under drought conditions, the application of humic acid fertilizer can increase the proline content of plant leaves, promote the water holding capacity of cells, increase the activities of plant cell protective enzymes (nitrate reductase, superoxide dismutase, peroxidase, etc.), and reduce the permeability of cell plasma membrane to comprehensively improve the drought resistance of crops.

The stress tolerance and stress resistance of plants can be improved indirectly by improving soil physical and chemical properties. In addition, humic acid can also regulate the change of fructose concentration to alleviate the damage of plasma membrane under salt stress, so as to enhance its salt resistance.

Under low temperature stress, humic acid can improve the cold resistance of plants by increasing proline content and abscisic acid content, enhancing polyphenol oxidase activity, and reducing the reduction of transpiration rate, stomatal conductance and net photosynthetic rate after low temperature stress. Under high temperature stress, humic acid also had good performance. The activities of superoxide dismutase (SOD) and peroxidase (POD) were increased, the production rate of superoxide anion and the content of hydrogen peroxide were decreased, and the heat resistance of crops was enhanced.

There are many functional groups in plant humic acid under heavy metal stress. Heavy metals can be immobilized on the surface of soil particles through complexation, chelation and reduction, which can affect their migration, reduce the water-soluble state of heavy metals and reduce their toxicity. At the same time, humic acid can also alleviate the toxic effect of cadmium on seedlings, the main mechanism is to inhibit its absorption of cadmium, and promote its absorption and accumulation of copper, zinc, iron, manganese and other nutrients.

Plant disease resistance

Humic acid can promote the growth by increasing the sugar content and chlorophyll content of leaves, and indirectly improve the disease resistance of crops. At the same time, studies have shown that sodium humate can inhibit the spore sac germination of downy mildew, and its combination with other pesticides can significantly reduce the occurrence of downy mildew. At the same time, humic acid can also enhance the control effect on root knot nematode. Because of its special structure and function, phytic acid is widely used as pesticide adjuvant, which also proves that humic acid has a good effect on plant disease resistance.

Why can humic acid improve the stress resistance of crops? Zhongshan chuangshuo Plastic Machinery Co., Ltd., co rotating parallel twin-screw extruder, central feeding system, weight-loss metering feeder, screw elements, barrel, heater, wear-resistant alloy sleeve, plastic machinery accessories