Dear Asad Ali Khan,

the product of removing or eliminating soil micro-biome from soil is a sterile ("dead") soil often used in soil science to study soil processes that are governed by soil micro-organisms => in comparison to physico-chemical processes. Although the importance of soil micro-organisms is well known their diversity and functionality are hardly understood, but luckily awareness and number of research projects increases. See some literature/web links you may use as a starting point for an own literature survey:

https://en.wikipedia.org/wiki/Soil_microbiology

http://www.futuredirections.org.au/publication/living-soils-role-microorganisms-soil-health/

BR

Nils

Thanks Dear Nils Borchard for providing useful information about soil microorganisms and concerned literature.

Microorganisms such as bacteria and fungi play an important role in maintaining the soil fertility. Microbial action on dead organic matter releases nutrients in the soil thus raising the fertility status of the soil. Diazotrophic bacteria and cyanobacteria like Azotobacter, Bacillus, Beijerinckia, Clostridium, Klebsiella, Nostoc, Anabaena, Anabaenopsis, etc. raise the nitrogen status of soil by fixing atmospheric nitrogen. Moreover, phosphate solubilizing bacteria and fungi increase phosphorus availability to plants in the soil. Microorganisms also improve the soil structure which protects the soil against erosive forces.

http://www.soilquality.org.au/factsheets/soil-biological-fertility

Thanks Arvind Singh for useful answer

Transformation of organic material into assimilable substances for the plants, nitrogen fixation ,degradation of inorganic phosphates, metabolism of ammonia, detoxification of some synthetic organic substances

· Microorganisms play an important role in the decomposition of organic matter. Different types of microbes are specialised to different types of organic matter, between them covering just about everything.

· Soil microbes play a crucial role in returning nutrients to their mineral forms, which plants can take up again. This process is known as mineralization.

· Some soil microbes secrete polysaccharides, gums and glycoproteins, which glue soil minerals together, forming the basis for soil structure. Fungal hyphae and plant roots further bind soil aggregates together. Soil structure is essential to good plant growth.

· Some soil microbes produce a variety of substances that promote plant growth, including auxins, gibberellins and antibiotics.

Thanks Gonzalo Galileo Rivas Platero for informative answer.

Definitely a good soil structure is essential for healthy soil.

Microorganisms contribute to biological fertility of soil. They take part in nutrient cycling.Highest population is of bacteria that release nutrient from inaccessible form to usable form. They can be nitrogen fixer (symbiotic and free living), Plant growth promoting bacteria, phosphate solubilizer, cellulolytic, plant disease controlling bacteria and also used for soil bio-remediation

Fungi are decomposer ( convert dead OM to CO2, organic acids and fungal biomass. Cellulolytic and lignolytic fungi convert complex carbohydrates to simpler form of carbohydrates. Mycorrhizal fungi bring nutrient (P) into soil solution.

Algae add organic matter into soil, help in increasing the water retention capacity of soil, release large amount of O2 in soil environment through photosynthesis and thus facilitate submerged aeration.

Protozoa play important role in maintaining microbial equilibrium in soil

Soil without microorganism is dead soil

One of the most important roles of soil organisms is breaking up the complex substances in decaying plants and animals so that they can be used again by living plants. This involves soil organisms as catalysts in a number of natural cycles, among the most prominent being the carbon, nitrogen, and sulfur cycles. Soil microorganisms are responsible for most of the nutrient release from organic matter. When microorganisms decompose organic matter, they use the carbon and nutrients in the organic matter for their own growth. They release excess nutrients into the soil where they can be taken up by plants.

Kaushik Kumar Panigrahi thanks for providing informative and very useful answer.

Microorganisms present in the soil are responsible for decomposition of present /added organic materials so as to release nutrients adequately for plant uptake...Microorganisms viz bacteria fungi and actinomycetes governs carbon:nitrogen ratio(mineralization and immobilization), nutrient transformation, decaying process and even modify physical chemical and biological environment of the soil..

Thanks Himanshu Verma for adding a useful answer about the role of soil micrograms.

https://www.futuredirections.org.au/publication/living-soils-role-microorganisms-soil-health/

https://link.springer.com/chapter/10.1007/978-3-319-49724-2_5

Carine Temegne Nono thanks for referring informative and useful material.

The soil contains a vast number of microorganisms including the usual order of abundant bacteria, actinomyces, moulds, algae, and protozoa. Each kind produces chemical changes which influence the development of all other organisms. This mass of organisms, including insects and worms, is highly active and brings about changes that develop soils and create and maintain fertility.

Thanks Harasit Kumar Paul for your very useful response on the question under inquiry.

Dear @Asad Ali Khan

Microorganisms may contribute directly (i.e., biological N2 fixation, P solubilization, and phytohormone production, etc.) or indirectly (i.e., antimicrobial compounds biosynthesis and elicitation of induced systemic resistance, etc.) to crop improvement and fertilizers efficiency. Please see following two links:

https://doi.org/10.3389/fmicb.2018.01606

http://www.soilquality.org.au/factsheets/soil-biological-fertility#:~:text=Soil%20microorganisms%20(figure%201)%20are,be%20taken%20up%20by%20plants.

Thanks!

Arbind K. Choudhary thanks for your response and for referring very informative material.

There is no doubt about the role of micoorganisms in maintaining the soil fertility , we have been taught in our school days , probably our teachers as well...and so on . These days , more important is to debate on issues which could ensure the consistent repsonse of micorbial inoculation , development of bioformualtions, encapsulated inoculants...and so on ...Lets debate on issues which could see the next generation micorbial research ,so that researchers hooked up through this thread get some food for thought.....my humble submission ....

Anoop Kumar Srivastava thanks for wonderful idea.

Microorganisms play an important role in the decomposition of organic matter. Different types of microbes are specialized to different types of organic matter, between them covering just about everything.

Abdelmonnem Sadalaha Kahle thanks for brief and meaningful answer of the question under investigation. It means microorganisms working on soils are performing huge job and they are free of cost labour gifted to humans.

Microorganism are the key functioning group responsible for quality, health and fertility status. For example Nitrogen fixing bacteria, phosphorous and potassium solublizing bacteria and organice matter degrader. Thess elements are mostly in availible form and they are the microorganism which convert them into availible form. Moreover, by intercropping legumes (N fixing crop) with cereal crop can help improve the N requirement of cerarl which are most often related to below ground microbial ecological environment. There are many functions involve which still unclear and no one has to explain fully. But in short note microoragisms are free labour

Thanks for informative response

Yes Jamal Nasir free of cost highly effective labour

They have a huge impact on soil fertility through their role in nutrients release since they depend on organic matter carbon as a food . moreover, they supply the soil with a rich variety of nutrients

Thanks

Aseel Hatif for your interest and valuable response.

No doubt there are numerous beneficial effect of microbes. Few microbial strain also help to reduce the disease causing organisms.

Let us throw some light on metagenomics of microbes , especially about the culture independent microbes, lot of novel possibilities exist....

Subhrajyoti Mishra thanks for your worthwhile response that enhanced my knowledge about the role of microbes.

very good

I need this article for articles

Microorganisms as such don't involve directly in maintaining soil fertility so as to provide adequate nutrient with suitable proportions. however these microorganisms make plant nutrients available for plant uptake considering many more mechanisms. Some of the mucilages and other secretions involve in the process of release of micro and macro nutrients from the clay surface making it more vulnerable in soil solution form which is the immediate form for uptake by roots... microorganisms take part in mineralisation processes whereby non available form is converted in available forms.. polysaccharide yielded by these microorganisms has tremendous role in binding sand silt and clay thereby making stable aggregation resulting in good physical condition of the soil..by this, there will be good contact and coordination of a nutrient with medium that is soil and with flowing material that is water, in question...

Soil microorganisms are responsible for most of the nutrient release from organic matter. When microorganisms decompose organic matter, they use the carbon and nutrients in the organic matter for their own growth. They release excess nutrients into the soil where they can be taken up by plants. If the organic matter has a low nutrient content, micro-organisms will take nutrients from the soil to meet their requirements.Diazotrophic bacteria and cyanobacteria like Azotobacter, Bacillus, Beijerinckia, Clostridium, Klebsiella, Nostoc, Anabaena, Anabaenopsis, etc. raise the nitrogen status of soil by fixing atmospheric nitrogen. Moreover, phosphate solubilizing bacteria and fungi increase phosphorus availability to plants in the soil. Microorganisms also improve the soil structure which protects the soil against erosive forces. Let us throw some light on metagenomics of microbes , especially about the culture independent microbes, lot of novel possibilities exist..

1. Fixing atmospheric nitrogen

2. Increasing phosphorus availability

3. Degrading pesticides

4. Controlling pathogens

5. Improving soil structure

6. Managing soil biological fertility

Following are advantages

1. Maintain or increase the organic matter content of soil as organic matter is an important source of carbon, energy and nutrients for soil organisms.

2. Use diverse rotations as they result in diverse inputs of organic matter and a diverse population of soil organisms.

3. Select nitrogen fixing bacteria that match the host plant and can tolerate your soil characteristics (e.g. pH) as nitrogen fixing bacteria form specific associations with legumes.

4. Consider the release of nutrients from organic matter when determining fertiliser applications.

5. Use fertiliser inputs that complement the activities of arbuscular mycorrhizal fungi as they only increase plant uptake of phosphorus in phosphorus-deficient soils.

6. Choose crop rotations and management practices that decrease the suitability of soil for plant pathogens.

7. Be patient as soil biological processes take time to develop. Minimise erosion as soil organisms are predominantly located in the surface layers, which are most easily eroded.

Prem Baboo thanks for your valuable response on the issue under consideration.

Soil microbiota plays an extremely important role in activating nutrient elements for plants—especially nitrogen fixation, phosphorus, and iron activation—as well as interactions and communication (plants–microorganisms), explaining the ecological equilibrium in soil.

Raigar Om Prakash thanks for your worthwhile response about the question.......

Soil microbes significantly affect soil and crop health. Some of the activities they perform include nitrogen fixation, phosphorus solubilization, the suppression of pests and pathogens, the improvement of plant stress, and decomposition that leads to soil aggregation. Also, microorganisms are used in the bioremediation of pesticides and other xenobiotics in soil. 

In general, the metabolic activity of the microorganisms is mainly important for maintaining the soil fertility since they convert all nutrients present in soil for better availability to plants. Microorganisms play a critical role in increasing water holding capacity and porosity of the soil thereby maintaining the pH as well.

Some of the specific activity performed by microorganisms are nitrogen fixation, phosphorus solubilization, iron activation, decomposition of waste (to make it available form) and release of plant growth promoting hormones which eventually contribute to soil fertility.

Parikh Dipti thanks for your interest in the issue and precise answer, helpful to understand it.

I agree with Dr Arvind Singh that soil microorganisms, including bacteria, fungi, viruses, protozoa, and archaea are essential for the growth of plants by providing nutrients to the plants, through the process of mineralization of organic content. Microorganisms have several vital roles in ecosystems: decomposition, oxygen production, evolution, and symbiotic relationships. Decomposition is where dead animal or plant matter is broken down into more basic molecules. This process only happens because of the microorganisms that find their way into the dead matter. Microorganisms help break down organic matter, they release essential nutrients and carbon dioxide into the soil, fix nitrogen and help transform nutrients into mineral forms that plants can use through a process called mineralization and nitrogen fixing bacteria improve soil fertility. Biofertilizers are biological preparations of efficient microorganisms that promote plant growth by improving nutrient acquisition. They enhance soil productivity by fixing atmospheric nitrogen, solubilizing soil phosphorus, and stimulating plant growth. When microorganisms decompose organic matter, they use the carbon and nutrients in the organic matter for their own growth. They release excess nutrients into the soil where they can be taken up by plants. These microbes regulate nutrient cycling, regulation of dynamic of soil organic matter, and enhance efficiency of nutrient acquisition. The symbionts of microbes enhance the efficiency of nutrient acquisition of nutrient and water by plants.

Rk Naresh yes

His answer is very precise and helpful......