Respected sir

Rk Naresh

Microorganisms are essential for soil fertility and crop production cycles as they decompose organic matter, release nutrients, and enhance soil structure, making nutrients more accessible to plants. They play a pivotal role in nitrogen fixation, phosphorus solubilization, and other nutrient cycles, directly impacting crop productivity. In mineral transformation, microorganisms convert inorganic minerals into bioavailable forms through processes like weathering and solubilization. This transformation is crucial for making essential nutrients, such as phosphorus and potassium, accessible to plants, thereby sustaining soil fertility and promoting healthy crop growth.

Dr Himanshu Tiwari thank you for your contribution to the discussion

PGPR contain nitrogen fixing and symbiotic bacteria (e.g. Rhizobium, Azospirillum, Azotobacter, Mycobacterium, Bacillus, Azobacter, Serratia, Xanthomonas, Proteus, Pseudomonas, Clostridium).

Plant growth promoting fungus viz.Aspergillus, Penicillium, Fusarium, Trichoderma. Plant growth promoting cynobacteria(Anabaena, Tolypothrix, Aulosira etc.)

Micro-organisms such as Nitrosomonas and Nitrobacter are essential for nitrogen fixation, Nitrogen fixing cyanobacteria, Phosphate solubilizing bacteria mobilize unavailable form of Phosphorus. Arbuscular mycorrhizal fungi are well-reported fungi that promote nutrient assimilation in plants.

Entomopathogenic fungus such as Trichoderma spp, Metarhizium anisopliae, Paecilomyces lilacinus, Beauveria bassiana. entomopathogenic nematodes-Heterorhabditis bacteriophora used against moths, flies, weevil and other pests. Endoparasitoid viz., Leptomastix nigrocincta Risbec and Aenasius spp. feeding on brinjal mealybug. Stenotrophomonas maltophila bacteria as antagonistic to Fusarium oxysporum. Some Parasitoid wasps: Pambolus infuscatus and Paroplitis khajjiarensis also control many insects so micro-organisms have a significant role of controlling disease-pests and in mineral transformation.

Dr Ashok Kumar Meena thank you for your contribution to the discussion

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 from the humus into the soil where they can be taken up by plants. Therefore, soil organic matter encompasses all organic components of a soil: fresh residues, decomposing organic matter, stable organic matter, and living organisms.

Function of humus:

It holds water and nutrients;

• sticks together & helps establish and maintain a strong crumb structure & thus reduce soil erosion

• provides some nutrients (N & P) as it is slowly decayed by microbial activity,

• Buffers effects of pesticides

• humus creates good soil “ Tilth”

•coats the sand, silt, clay particles making them dark and the darker the color, the greater the amount of soil humus.

Dr Bahire Addisu thank you for your contribution to the discussion

Dr Bahire Addisu thank you for your contribution to the discussion

Soil microorganisms play a vital role in soil fertility and crop production cycles by improving plant nutrition, increasing soil organic matter, and regulating soil characteristics. Soil fertility can be further improved by incorporating cover crops that add organic matter to the soil, which leads to improved soil structure and promotes a healthy, fertile soil; by using green manure or growing legumes to fix nitrogen from the air through the process of biological nitrogen fixation. 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. Microorganisms, or microbes, play a key role in mineral transformation, including mineral formation, deterioration, and bioweathering. Here are some ways that microbes affect minerals:

· Mineral dissolution and rock degradation

Microbes help release elements from geological reservoirs and perform elemental transformations by facilitating mineral dissolution and rock degradation. For example, some microbes can accelerate the oxidative dissolution of sulfide minerals, which can lead to acid mine drainage.

· Biomineralization

Microbes are responsible for the formation of a wide range of minerals, including iron oxides, carbonates, and silicates.

· Mineralization

Microbes convert immobilized elements into inorganic forms that plants can easily absorb. As phosphate-solubilizing bacteria can hydrolyze organic and inorganic phosphorus from insoluble compounds.

· Nutrient cycling

Microbes and plants are coevolved and play a key role in nutrient cycling through decomposition and mineralization of organic material. Microbes also release nutrients from minerals that are essential for their own nutrition, which in turn augments the soil and influences other microbial communities.

· Nitrogen cycle

Microorganisms catalyze the transformation of soil nitrogen into forms that plants can use. They can also take nitrogen from the atmosphere and supply it directly to plants.

· Phosphorus bioavailability

Microorganisms increase the bioavailability of phosphorus in soil through enzymatic activities and other components. This process transforms insoluble phosphorus into forms that plants can use.

· Iron availability

Microorganisms produce binders, such as siderophores, that make iron available to plants. They transform iron in the soil into absorbable forms that plants can use.

· Organic matter

Microorganisms increase soil organic matter by decomposing plant and animal residues. This improves the soil's fertility retention capacity and buffer performance.

· Carbon cycling

Microorganisms play a key role in carbon cycling by participating in the decomposition and transformation of organic matter. This process contributes to the stabilization of organic carbon, which influences how much carbon the soil stores and how quickly it turns over.

· Water storage and fertilizer conservation

Microorganisms regulate soil characteristics, which can improve the soil's capacity to store water and conserve fertilizer.

Microorganisms also help make organic fertilizers and biofertilizers, which are eco-friendly and can improve soil fertility. 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. Microorganisms may effect the solubilization of mineral phosphates in different ways: (i) by the formation of carbon dioxide and particularly of organic acids, (ii) by exerting a reducing effect on ferric phosphates which are converted to the more soluble ferrous compounds, (iii) by the production of hydrogen sulphide