Soils are filled with millions of billions microorganisms that keep the soil as a living body. Soil microorganisms include microflora and microfauna.

Microflora includes autotrops like vascular plants (root hairs), algae (greens, diatoms, yellow-green algae); heterotrops like fungi (yeasts, mildews, molds, rusts, mushrooms); bacteria (aerobic and anaerobic), cyanobacteria (BGA), actinomycetes and Archaea (methanotrophs, halophiles, Thermoplasma sp.), and microfauna includes Nematodes, Rotifera, Protozoa (amoebae, ciliates, flagellates), and Targrades like Macrobiotus sp.

They are valuable to soil for balancing soil nutrient cycles. They influence on soil fertility, productivity and environmental quality.

Bacteria are important for organic material decomposition, breakdown of toxic compounds, inorganic transformation, Nitrogen fixation, growth promotion of plants by rhizobacteria and plant protection from harmful pests and pathogens.

Dr Bishal Dhungana thank you for your contribution to the discussion

There are many different types of microorganisms that live in soil, but some of the most common include:

• Bacteria: These are tiny, one-celled organisms that can be found in almost every environment on Earth. In soil, bacteria play an important role in decomposing organic matter, which helps to release nutrients that plants can use. They also help to fix nitrogen from the air, making it available to plants.📷Opens in a new window📷www.southlandorganics.comBacteria in soil

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• Fungi: These are larger, multicellular organisms that can be found in the form of molds, yeasts, and mushrooms. Fungi help to break down organic matter in soil, and they also form symbiotic relationships with plant roots, helping plants to absorb nutrients from the soil.📷Opens in a new window📷newscientist.comFungi in soil
• Actinomycetes: These are filamentous bacteria that are similar to fungi in appearance. Actinomycetes help to decompose organic matter in soil, and they also produce antibiotics that can help to protect plants from disease.📷Opens in a new window📷www.frontiersin.orgActinomycetes in soil
• Protozoa: These are single-celled organisms that are larger than bacteria. Protozoa help to decompose organic matter in soil, and they also prey on bacteria and other microorganisms.📷Opens in a new window📷www.sciencephoto.comProtozoa in soil
• Nematodes: These are tiny, worm-like animals that live in soil. Nematodes help to decompose organic matter in soil, and they also prey on bacteria, fungi, and other microorganisms.📷Opens in a new window📷eorganic.orgNematodes in soil

These microorganisms are all essential for maintaining soil fertility. They help to break down organic matter, which releases nutrients that plants can use. They also help to create soil structure, which allows water and air to move through the soil. In addition, some microorganisms can help to protect plants from disease.

Here's a more detailed explanation on the role of bacteria in maintaining soil fertility:

• Decomposition: Bacteria break down dead plant and animal matter into simpler organic and inorganic compounds. This process releases nutrients that plants can then take up and use for growth.
• Nitrogen fixation: Certain types of bacteria can convert nitrogen gas (N2) from the atmosphere into a form that plants can use (ammonium, NH4+). Nitrogen is an essential nutrient for plant growth, and bacteria play a vital role in making it available in the soil.
• Nutrient cycling: Bacteria play a key role in the cycling of nutrients in the soil. They help to convert nutrients from organic forms (unavailable to plants) into inorganic forms (available to plants) and vice versa. This ensures a constant supply of nutrients for plants.
• Soil aggregation: Bacteria help to bind soil particles together, which improves soil structure. This allows for better infiltration of water and air into the soil, creating a more favorable environment for plant growth.
• Plant growth promotion: Some bacteria produce growth-promoting substances that can stimulate plant root development and nutrient uptake. They can also help to protect plants from diseases caused by other microorganisms.

In conclusion, soil microorganisms are essential for maintaining soil fertility. They play a vital role in decomposition, nutrient cycling, soil structure formation, and plant growth promotion. By understanding the importance of these microorganisms, we can take steps to promote their growth and activity in our soils.

Soil is a complex environment teeming with a wide variety of microorganisms that play critical roles in ecological and agricultural systems. The primary types of microorganisms in soil include: 1. **Bacteria**: These are the most abundant microorganisms in the soil. They're involved in various processes such as nitrogen fixation, decomposition of organic matter, and nutrient cycling. 2. **Fungi**: Fungi break down complex organic materials, releasing nutrients back into the soil, and they also form symbiotic relationships with plant roots (mycorrhizae), which can help plants absorb nutrients and water. 3. **Protozoa**: These are single-celled eukaryotes that feed primarily on bacteria. Their predation on bacteria is instrumental in regulating bacterial populations and releasing nutrients for plant use. 4. **Viruses**: Though not technically considered living entities, viruses do abound in the soil where they infect other microorganisms, particularly bacteria, influencing microbial population dynamics, diversity, and gene flow. 5. **Actinomycetes**: A type of filamentous bacteria, they are crucial for breaking down tough plant and animal tissues such as cellulose and chitin, thereby contributing significantly to decomposition and humus formation. 6. **Algae**: Soil-dwelling algae, mostly microalgae, contribute to soil structure and fertility through their photosynthetic production of organic matter and oxygen. 7. **Nematodes**: Although not all nematodes are beneficial, many play roles in nutrient cycling by breaking down organic material, and others can help control populations of soil pests. The role of bacteria in maintaining soil fertility is especially important for several reasons: - **Nutrient Cycling**: Bacteria decompose organic matter, which recycles nutrients back into the soil for plants to use. They are especially important in the nitrogen cycle, where different bacteria are involved in nitrification, denitrification, and nitrogen fixation. - **Nitrogen Fixation**: Some bacteria such as Rhizobium, which live in symbiotic relationships with leguminous plants, fix atmospheric nitrogen into forms plants can use. This is especially important for agricultural systems that rely on the natural input of nitrogen to reduce the need for chemical fertilizers. - **Enhancing Soil Structure**: Bacterial exudates can help stabilize soil aggregates, which improves the soil structure, promoting better water retention, aeration, and root development. - **Disease Suppression**: Some bacteria produce substances that are toxic to plant pathogens and pests, thereby protecting plants from diseases and reducing the need for

Dr Robert Faust thank you for your contribution to the discussion

Soil microorganisms can be grouped into bacteria, actinomycetes, fungi, algae, protozoa, and nematodes. Apart from the dead plant or animal residues in soils, SOM is composed of a significant content of living microorganisms and their dead fractions. Soil microorganisms, including bacteria, fungi, viruses, protozoa, and archaea, perform vital ecosystem functions, such as decomposition and nutrient cycling, and form symbiotic relationships with plants. N-deposition can alter soil microbial community structure and function in multiple ways. Microorganisms help to generate oxygen and carbon dioxide, as well as fix atmospheric nitrogen into useable forms for multiple organisms. They also help animals ingest food by being part of the gut microbiome. Some species of microbe are symbiotic in nature. These organisms have many tasks, and are central to crop fertility, purifying the environment from pollutants, regulating carbon storage stocks and production/consumption of many significant green house gases, such as methane and nitrous oxides. Within food plant cropping systems, microorganisms provide vital functions and ecosystem services, such as biological pest and disease control, promotion of plant growth and crop quality, and biodegradation of organic matter and pollutants. Bacteria increase soil fertility through nutrient recycling such as carbon, nitrogen, sulphur and phosphorus. Bacteria also help in the decomposition of dead organic matter and then give out simple compounds in the soil, which can be used up by plants. Soil microorganisms, including bacteria, fungi, viruses, protozoa, and archaea, perform vital ecosystem functions, such as decomposition and nutrient cycling, and form symbiotic relationships with plants. N-deposition can alter soil microbial community structure and function in multiple ways.