Bacteria mainly contained in soil can be divided into two categories: spore-bearing bacteria and spore-free bacteria. According to the shape, it can be divided into cocci, bacilli, vibrios and spirillus. According to the way of nutrition, it can be divided into autotrophic, facultative autotrophic and heterotrophic bacteria. According to the demand for oxygen in the air, it can also be divided into aerobic bacteria and anaerobic bacteria.

Bacteria are the most diverse and abundant soil microorganisms. Each gram of soil can contain millions to hundreds of millions, and the content of fertile soil is higher.

There are many kinds of soil microorganisms, just to inhibit harmful bacteria and use some nutrients needed by plants produced by these bacteria. If effective sunlight is used, bacteria, fungi, actinomycetes and protozoa can be effectively killed, and rotting corpses can be used as nutrients.

The number of soil microorganisms is huge, and there are hundreds of millions to tens of billions of species in 1 g soil. In the topsoil of 1 mu, the weight of microorganisms ranges from several hundred kilograms to several thousand kilograms. The more fertile the soil, the higher the utilization rate of microorganisms.

The role of soil bacteria:

With the succession of vegetation community, the number of Proteobacteria, Firmicutes and Hemifungi in rhizosphere soil gradually increased. The abundance of Acinetobacter and micro-fungi in non-rhizosphere soil decreased with vegetation succession.

The influencing factors of soil bacteria are soil organic carbon, soil total nitrogen, water content and electrical conductivity, among which soil organic carbon and soil total nitrogen have significant effects. Bacteria and other soil microorganisms can participate in the formation of humus and the complete mineralization of organic matter.