A microbial fertilizer, a product that uses the life activity of microorganisms to give crops a specific fertilizer effect, is a type of fertilizer in agricultural production. Microbial fertilizers play an important role in agriculture, not only in improving the availability of soil nutrients but also in promoting crop growth, disease resistance and resilience.
The function of microbial fertilizers
After microbial fertilizers are applied to the soil, a “coexistence and co-prosperity effect between bacteria and crops”, “nutrient coordination effect”, “biological nitrogen fixation effect”, etc. will occur among the species, crops and soil ecology to ensure the healthy growth and stable yield increase of the crop.
Increase soil fertility and improve fertilizer utilization Microbial fertilizers are rich in organic matter and a certain amount of quick-acting nitrogen, phosphorus, potassium and trace elements, with comprehensive nutrients, increasing soil fertility; at the same time, the combined action of multiple high-efficiency strains of beneficial microbial flora has the effect of decomposing phosphorus and potassium, while increasing soil porosity and improving the utilization rate of nitrogen, phosphorus, and potassium in conventional fertilizers. For example, bacteria can gradually break down apatite and tricalcium phosphate, as well as organophosphorus compounds, releasing phosphorus pentoxide for plant uptake for reuse.
Improving soil granular structure and loosening up the soil Microorganisms produce large amounts of extracellular polysaccharides during growth and reproduction. Extracellular polysaccharides are the binders that form the structure of soil glomeruli and keep them stable. Bacteria synthesizing polysaccharides around the root system are linked to the stability of aggregates in the soil between the roots of the crop. In addition, the organic matter contained in microbial fertilizers can improve the organic matter content, improve the soil structure, loosen the activation of the soil, reduce soil clumping, improve the ability of the soil to retain water, fertilizer and air permeability.
Promote crop growth and increase crop resilience Microorganisms are able to produce large amounts of phytohormone-like substances, such as erythromycin and cytokinin, during the fermentation process and life activity in the soil, which, when in contact with the crop root system, stimulate crop growth and regulate crop metabolism.matterial fertilizers contain organic matter and humic acid that regulate the opening of crop stomata, which work in synergy with the metabolites (enzymes) of beneficial microorganisms to improve crop resilience.
Reduction of soil-borne diseases After the application of microbial fertilizer, microorganisms grow and multiply in large numbers in the crop root system, forming the dominant bacteria between the roots of the crop, through competition, parasitism, occupancy and other relationships, inhibit and reduce the chance of pathogenic bacteria to reproduce, some microorganisms can also produce antibiotics, lysozyme, and other active substances, effectively inhibit the growth of pathogenic bacteria in the soil, and play a role in reducing soil-borne diseases of crops.
Decomposition of hazardous substance residues in the soil The proliferation of microbial beneficial bacteria can inhibit the growth and reproduction of pathogenic bacteria and also decompose the residues of fertilizers and pesticides in the soil, decompose the harmful inter-root secretions accumulated in the soil and alleviate the crop crop crop disruption.
Common strains of microbial fertilizers In the development of national standards, the microbial agent is a category of microbial fertilizer, the Ministry of Agriculture and Rural Affairs microbial agent product registration certificate a total of 2,789 (including 936 liquid), the product registration of a total of about 152 species of bacteria, the frequency of use of the top 10 species are: Bacillus subtilis, jelly-like Bacillus subtilis, Bacillus licheniformis, Bacillus macrocephalus, Bacillus amylophilus, brewer’s yeast, Bacillus subtilis, Streptomyces falciparum, Lactobacillus plantarum, Aspergillus niger, of which Bacillus subtilis accounted for 75%.
At present, in the market promotion, microbial fungicides according to the microbial species contained in the functional characteristics are divided into: rhizobial fungicides, nitrogen-fixing fungicides, phosphate microbial fungicides, silicate microbial fungicides, photosynthetic bacterial fungicides, organic material decay agents, probiotic agents, mycorrhizal fungicides, bioremediation fungicides; dosage form to liquid-based, there are also powder agents, granular type.
Bacillus subtilis A bacterium of the genus Bacillus, a Gram-positive bacterium.
Bacillus subtilis has a competitive relationship with pathogenic microorganisms, including both nutrient competition and spatial site competition. Bacillus subtilis has more advantage in spatial site competition, i.e., rapid and massive reproduction and colonization in the soil, effectively preventing the reproduction of pathogenic microorganisms, interfering with the infestation of plants by plant pathogenic microorganisms, and disrupting the colonization of pathogenic microorganisms on plants, thus achieving the effect of fungus and disease control.
Bacillus subtilis has a lysophilic effect, which adsorbs on the mycelium of the pathogenic fungus and grows with the mycelium together, which produces lysophilic material during growth, thus disintegrating the mycelium.
Bacillus subtilis produces antimicrobial substances that produce antibiotic-like substances that inhibit the growth of bacteria, viruses, fungi, and pathogens, which are dominated by antibiotics such as phospholipids, aminosaccharides, peptides and lipopeptides. Among them, lipopeptide antibiotics are the most important antibacterial substances of Bacillus subtilis.
Bacillus amyloliquefaciens It is a bacterium with a high affinity to bacillus amyloliquefaciens, a safe strain of Gram-positive bacteria that is harmless to humans and animals. It is capable of forming endogenous budding spores, is motile, and produces a range of antibacterial metabolites during its growth. In nature, Bacillus amylophilus is, widely found in soil, leaves, and fruits between plant roots.
Bacillus amylophilus can secrete an,timicrobial substances, mainly antibacterial proteins (natural antibiotics), peptides, lipopeptides, and polyketides. In addition, Bacillus subtilis is able to suppress a variety of pathogenic bacteria through competition for ecological positions and induction of systemic resistance.
Bacillus licheniformis A bacterium of the genus Bacillus, a Gram-positive bacterium.
Bacillus licheniformis will multiply rapidly in the soil, occupy space, can secrete protease, lipase, amylase, and cellulase, promote the degradation of field straw, bran, etc., so that plants can effectively absorb the nutrients therein.
Bacillus licheniformis can produce anti-active substances, including nucleic acids, amino acids, humic acids, etc., and play a significant inhibitory effect on a variety of plants, animals and human pathogens, and are widely used in agricultural production.
Bacillus mucilaginosus Also known as silicate bacteria, it is a common soil bacterium used in farmland due to its life-acting action to dissolve the insoluble potassium in potassium-containing minerals for crop use. Jelly-like bacterium Bacillus mucilaginosus has the characteristics of rapid reproduction, strong vitality, safe and non-toxic. Bacillus jelly-like can decompose phosphorus, potassium, nitrogen fixation, greatly improve fertilizer utilization and reduce fertilizer use.
Paenibacillus polymyxa Bacillus pallidum, Bacillus subsp. genus is a budding Gram-positive bacterium with aerobic or parthenogenic anaerobic life.
Paenibacillus polymyxa can produce a variety of metabolic active substances available, according to its structure can be divided into peptides, proteins, polysaccharides, etc., such substances can be biological nitrogen fixation, can dissolve phosphorus, decreasing potassium, also has antagonistic microorganisms, promote plant growth and other functions. When applied to plants as a microbial fertilizer, it quickly settles in the inter-root and internal plant and forms a “biofilm” that promotes the absorption of nutrients by the plant.
Advantages and Disadvantages of Microbial fertilizers There is a wide variety of microbial fertilizers on the market. Feedback from the actual use, good microbial fertilizer can indeed effectively enhance plant resilience, improve soil grain structure, alleviate crop stubble and reduce soil-borne diseases. At the root, a good microbial fertilizer should have several of the following characteristics at once.
Excellent strains Microbial fertilizer strains should be used in the laboratory for repeated screening, physical and chemical identification, mechanism of action and characteristics of a clearer basis, after repeated field verification, to prove that in line with, production requirements, good fertilization effect of the excellent strains.
Production process optimization Choosing the right fermentation equipment will prevent contamination at all stages. The medium formulation, pH, temperature, ventilation, choice of sorbent and sterilization should be in accordance with the requirements of the species.
A low number of contaminants and high strain purity After the use of microbial fertilizer, only live bacteria, and the, bacteria measured by the standard of “effective live bacteria”, so it seems that the effective live bacteria the greater the effect of the better, is not entirely so. The purity of the strain is important when the number of mold contaminants in the product and the contaminant rate exceeds the standard can also affect the application, and there are a few substandardrd products on the market contain pathogenic bacteria, not only can not repair the soil but also cause disease.
Synergies between strains Microbial fertilizers are not about more strains and larger numbers. The effect of the use of compound microbial bacteria will be affected by the growth habit of different strains, blind compounding, it is very easy to cause antagonism between strains, affecting the effect. So it’s not that the more strains of the compound were the better, but that the strains can synergize and promote each other to achieve the best results.
Rational use of microbial fertilizers Microbial fertilizers should not be mixed with bacterial fungicides, fertilizers. Theoretically, bacterial fertilizers and microbial fungisubstandard mixed with fungicides, but in practice, the mixing of the two will reduce the activity of strains. And the high concentration of salt ions in the fertilizer can also affect the activity of the strain. So it is not recommended to mix microbial fertilizers with fungicides and fertilizers.
The growth of microorganisms has certain requirements for temperature, moisture and other environmental conditions, avoiding the use of high temperatures and dry conditions. Surviv,al and reproduction are compromised and do not work well in hot and dry conditions. This type of fertilizer should be applied in the evening on a cloudy or sunny day and combined with soil cover, manure cover, watering, etc., to avoid direct sunlight or lack of moisture to make micro fertilizers work.
