Amazing Bacillus subtilis!

Bacillus subtilis improves soil primarily by regulating soil nutrients, altering the soil microbial community structure, and decomposing residual pesticides in the soil.

Regulating Soil Nutrients: Bacillus subtilis and its secretions can accelerate the mineralization and release of nitrogen, phosphorus, and potassium, thereby increasing soil nutrients. However, the growth and reproduction of Bacillus subtilis itself consumes soil organic matter, so it is recommended to use it with organic fertilizers.

Altering Soil Microbial Community Structure: In healthy soil, the general order is bacteria > actinomycetes > fungi. However, in severely problematic soil, the number of certain fungi such as Fusarium, Botrytis cinerea, and Verticillium dahliae may increase, inducing various soilborne diseases. The colonization of Bacillus subtilis can alter the structure and diversity of soil microorganisms in the crop rhizosphere, significantly increasing the number of bacteria and actinomycetes, and significantly reducing the number of fungi.

Decomposing Residual Pesticides in Soil: Bacillus subtilis can help degrade substances harmful to plant growth, such as some herbicides, phorate, and profenofos, by increasing the activity of urease, protease, and sucrase in the soil.

On the one hand, Bacillus subtilis can promote crop growth; on the other hand, it can enhance disease resistance.

Promoting Crop Growth: Bacillus subtilis improves the soil, creating a favorable environment and nutritional conditions for the crop root system. In addition, the active substances secreted by Bacillus subtilis can stimulate an increase in the proportion of plant growth endogenous hormones, such as increased indoleacetic acid and gibberellin content and decreased abscisic acid content, contributing to increased yield.

Enhancing Disease Resistance: As mentioned earlier, Bacillus subtilis can reduce the number of pathogenic microorganisms in the soil, but this is only part of its disease-resistant effect.

Bacillus subtilis has colonization ability and can successfully colonize in the roots, stems, leaves, and soil of crops. When the colonization level reaches a certain level (10^4 CFU/g), it can hinder the infection and damage of pathogens to crops by competing for space and nutrients.

At the same time, after colonization, Bacillus subtilis can produce antibiotics and antimicrobial proteins, causing the hyphae to twist, swell, and deform, thereby inhibiting the growth of pathogenic bacteria and achieving disease control.

After Bacillus subtilis colonizes in the soil, it produces a large number of plant hormones and organic acids, stimulating root growth, improving soil quality, promoting crop physiological metabolism, and forming a benign plant-soil-microbe ecosystem, thereby effectively improving crop quality.