SOIL MICRO-ORGANISM – DISTRIBUTION AND IMPORTANCE
Soil micro-organism – distribution and importance
Functional soil is soil that is rich in nutrients and microbes that work together to retain soil nutrients and transform nutrients locked into the soil.
Soil is an ideal culture medium for the growth and development of various microorganisms. Living things in the soil are grouped into two groups: soil and soil animals.
Soil is a habitat or complex life cycle that provides habitat for many species of animals, such as worms and insects (invertebrates), mammals such as rabbits, moles, foxes, and badgers. It also provides a home for a variety of creepy-crawly microbes. All these forms of life interact with each other and the soil to create a dynamic environment. This allows for the early development of land settlement.
Normal soil is a solid, liquid and gas composition. These can be broadly divided into five categories: 1. Mineral particles. 2. Plant and animals. 3. Living system. 4. water. 5. Gases
Distribution of microorganisms in soil
Soil microorganisms can be divided into bacteria, actinomycetes, fungi, algae and protozoa.
Rhizosphere is the flat root zone. It is a very unique place where plants, soil, microorganisms, food and water meet and interact.
Microorganisms make up <0.5% (w/w) of soil mass, but they have a significant impact on soil properties and processes.
About 60-80% of the total soil metabolism is due to microflora. They are the smallest objects<;0.1 mm in diameter) and they are very large and varied.
They include algae, bacteria, cyanobacteria, fungi, yeasts, mycomycetes and actinomycetes. Most of them can damage anything in nature.
Soils represent a large part of the Earth’s biodiversity. They can be grouped according to their size, shape and function.
One gram of soil can contain: up to one million bacteria, up to 100 million actinomycetes, one million fungi and 100 nematodes.
Importance of soil organisms
- Microorganisms transform organic matter into plant nutrients that are assimilated by plant
- Responsible for the cycling of C, N and other nutrients.
- Improves soil structure.
- Move and decompose organic matter.
- Keep soil quality and health.
- Increases ventilation and penetrability of soil.
- Microorganisms in the soil destroy living things.
- Soil microbes produce humus.
- Micronutrients fix nitrogen.
- soil microbe promotes plant growth.
- Soil microbes control pests and diseases.
Soil environment and soil life
Soil microorganisms are affected by biotic and abiotic factors, such as vegetation cover or edaphic parameters. PH strongly affects the bacterial community of the soil.
Soil life is divided into three groups:
Macrofauna
These are visible to the naked eye < 2 mm in diameter). Macrofauna includes vertebrates (snakes, lizards, mice, rabbits, moles, etc.) that burrow into the soil for food or shelter, and invertebrates (snails, earthworms, ants, termites, centipedes, centipedes, caterpillars) , larvae and told beetles). , flies). and the larvae of wasps, spiders, scorpions, crickets and cockroaches) live and feed in or on the ground, on the surface litter and their components.
In fact, soil macrofauna are important factors that control decomposition, nutrient cycling, soil composition, and water movement through their nutrition and activity.
Mesofauna
Mesofauna (0.1-2 mm in diameter) includes nematodes, micro-arthropods, such as pseudo-scorpions, springtails, mites, and worm-like enchytreids. These are very dense and usually live in soil pores, feeding on organic matter, microflora, microfauna and other invertebrates.
Microfauna <;0.1 mm in diameter) includes protozoa. These usually live in the soil water film and feed on microflora, plant roots and other microfauna. They need to leave food from microorganisms microorganis.
Flora of the lower
It includes Macroffore (Vascula plant, Forms, etc.) and microflora (virus, Actinomycates, Fungi, Alarmeri).
Soil bacteria
They are very small cells that can be seen under an electron microscope.
They constitute the highest biomass of the soil assessment. They are abundant near the roots, one of their food sources.
From an agricultural perspective, Rhizobium and actinomycetes are important.
Bacteria are important in the soil because they contribute to the carbon cycle through photosynthesis and decomposition.
Some bacteria are important decomposers; some, like actinomycetes, are good at breaking down cellulose (which makes up the cell walls of plants) and chitin (which makes up the cell walls of fungi).
Soil actinomycetes
A transitional group between bacteria and fungi is called Actinomycetes.
Active in the degradation of resistant organic compounds. optimal growth at alkaline PH.
Make a vaccine with geosmin.
Adverse effects – potato scab.
soil fungi
It is responsible for decay in the environment as they break down and make cellulose, part of the plant cell wall. Controlling soil biomass.
Aerobes are important. Can survive desication
Dominating acid soil. It is useful – penicillium
Negative effects- Apple turning disease (Rhizoctonia, pythium, fusarium and phytophthora), powdery mildew.
Nutritional cycling and the function of microbes
The reactions in the elemental cycle are mostly chemical in nature, but biochemical reactions also play an important role in the elemental cycle.
Carbon cycle – Photosynthetic plants and microbes are the main producers of organic carbon compounds that are fed to other organisms. These organisms consume organic carbon and break down organic matter during the fermentation and respiration process. Chemoorganotrophic microbes break down carbon compounds to release carbon dioxide. Chemolithotrophic bacteria can assimilate inorganic carbon into dark matter.
Nitrogen cycle – Inorganic nitrogen compounds such as nitrates, nitrites and ammonia are converted into organic nitrogen compounds such as proteins and nucleic acids during the process of nitrogen assimilation. Many bacteria reduce nitrates and nitrites and reduce nitrites and ammonia. Nitrifying bacteria are responsible for the biological oxidation of ammonia.
