The Role of Microbes in Nutrient Cycling

Dr. Ankita Garkoti
Jul 2
6 min read

Introduction

Managing soil nutrients effectively is a crucial component of crop production, essential for ensuring optimal plant nutrition and maximizing crop yields. Microorganisms play a vital role in nutrient cycling by converting complex compounds into forms that are readily available to plants. This microbial activity not only supports plant growth and development, leading to enhanced yields, but also enriches the soil's nutrient content and promotes long-term soil health. By enhancing nutrient availability and uptake, microbes play a crucial role in supporting healthy plant growth and maintaining a balanced, productive agroecosystem.

Soil microorganisms have a profound impact on soil–plant-microbe interactions and are essential for sustaining soil health. Among these interactions, nutrient cycling is the most critical process supporting soil fertility and plant productivity. (1) Beneficial microbes play an essential role in decomposing complex organic and inorganic compounds, converting them into simpler, plant-available forms. For example, phosphorus-solubilizing microorganisms such as Bacillus species help release bound Phosphorus in the soil, making it accessible for plant uptake and thereby enhancing nutrient efficiency. Microbes play a crucial role in the ecosystem's nutrient-cycling processes.

In this blog, we will be discussing:

Nutrient Cycling

Role of Microbes in Nutrient Cycling

Microbes in Nitrogen Cycling
Microbes in Phosphorus Cycling
Microbes in Carbon Cycling

Nurture Growth Biofertilizer

Nutrient Cycling

Nutrients are essential for the growth and development of plants, and their continuous availability is maintained through a natural process known as nutrient cycling. This process involves the transformation, recycling, and reuse of nutrients within the ecosystem. Complex organic and inorganic compounds are broken down into simpler, plant-available forms, allowing for efficient nutrient uptake. Microorganisms play a crucial role in this cycle by facilitating these conversions, ensuring that essential nutrients are accessible to plants for optimal growth.

For example, Nitrogen-fixing bacteria such as Rhizobium and Azotobacter can convert atmospheric Nitrogen into simpler forms which plants can easily absorb. By fixing this atmospheric Nitrogen, these nitrogen-fixing bacteria contribute to nutrient cycling by enhancing Nitrogen availability and supporting plant growth.

Microbial Role in Nutrient Cycling

Soil microorganisms play a crucial role in regulating the availability of plant nutrients and maintaining soil quality. Plants, microbes, and soil are interconnected through a highly dynamic and complex relationship that drives nutrient cycling, plant health, and soil function. The interactions between plants and microbes play a fundamental role in sustaining the stability and functionality of natural ecosystems. (2,3)

Microorganisms such as Rhizobium, Azotobacter, Azospirillum, Bacillus, Pseudomonas, Aspergillus, Thiobacillus, and Mycorrhizal fungi, like Glomus are examples of microbes that play an essential role in nutrient cycling.

Soil microorganisms are important in nutrient cycling because they convert complex elements into simpler forms through natural processes and provide essential elements such as Nitrogen, Phosphorus, potassium, and sulphur to plants. Here are some of the important microbes involved in nutrient cycling:

Nitrogen-fixing Microbes in Nitrogen Cycle:
Nitrogen-fixing bacteria are essential to the nitrogen cycle, as they convert atmospheric Nitrogen into forms that plants can absorb through the process of nitrogen fixation. Nitrogen fixation is a biological process in which atmospheric Nitrogen is converted into simpler forms, such as ammonia or nitrates, with the help of Nitrogen fixing bacteria and is easily absorbed by plants.(4) The fixed Nitrogen in the form of nitrates, which are in excess and cannot be used by plants, is again converted to nitrogen gas or nitrous oxide with the help of denitrifying bacteria, and this process is known as denitrification.
Rhizobium, Azotobacter, Frankia, Azospirillum, and Clostridium are some important examples of nitrogen-fixing bacteria.

Phosphorus solubilizing microbes in the Phosphorus Cycle:

Although Phosphorus is abundant in soil, it is often present in complex mineral and organic forms that are not readily accessible to plants. Phosphorus-solubilizing microbes play a crucial role in phosphorus nutrient cycling by converting insoluble forms of Phosphorus into soluble forms that plants can readily absorb, thereby enhancing its availability in the soil ecosystem. Microorganisms facilitate this process through the secretion of organic acids, which lower the soil pH and promote the dissolution of bound, unavailable forms of Phosphorus (P), making them accessible to plants.

The production of organic acids, such as oxalic acid, fumaric acid, lactic acid, maleic acid, and formic acid, is a beneficial effect of phosphorus-solubilizing bacteria. These acids are responsible for lowering the pH of the soil and help break down unavailable Phosphorus into a simpler form that plants can absorb.

Bacillus, Pseudomonas, Burkholderia, Enterobacter, Mycobacterium, and Erwinia are examples of phosphorus-solubilizing bacteria. (5)

Microbes in Carbon Cycle

Soil systems host an incredibly diverse community of microorganisms. Among them, efficient soil microbes play a critical role in driving biological transformations and regulating the cycling of Carbon, as well as macro- and micronutrients. These processes are essential for establishing and maintaining effective soil–plant–microbe interactions that support plant growth and soil health. (6) The carbon cycle is balanced by two important processes, which are photosynthesis and respiration.

The Carbon dioxide present in the atmosphere is converted into Carbon by autotrophic organisms, mainly photosynthesizing plants and also photo- and chemoautotrophic microbes. (7) The conversion of atmospheric carbon dioxide into simpler carbon compounds is known as carbon fixation. This fixed Carbon Is returned to the atmosphere through the process of respiration in both autotrophic and heterotrophic organisms. Various microorganisms, including fungi and bacteria, break down organic matter, releasing carbon dioxide and contributing to the formation of soil organic carbon. (8)

Nurture Growth Biofertilizer

Nurture Growth Biofertilizer plays a crucial role in supplying plants with essential nutrients. Enriched with a variety of beneficial microorganisms, this biofertilizer serves as a powerful microbial solution that not only enhances nutrient availability for plants but also promotes overall soil health.

This biofertilizer contains important nitrogen-fixing microorganisms such as Rhizobium and Azotobacter, which play a vital role in the nitrogen cycle. These microbes can convert atmospheric Nitrogen into ammonia or other usable forms of Nitrogen, which plants can easily absorb through the process of biological nitrogen fixation. This natural conversion enriches the soil with plant-available Nitrogen, one of the most essential macronutrients for plant growth.

This biofertilizer also contains microorganisms such as Bacillus subtilis and Bacillus pumilus, which play a significant role in breaking down complex and insoluble phosphorus compounds present in the soil. These beneficial bacteria release organic acids and enzymes that help convert bound forms of Phosphorus into soluble forms that plants can readily absorb. By enhancing phosphorus availability, these microbes contribute to improved root development and overall plant productivity.

It also contains some beneficial microbes that play an important role in decomposition and help increase the organic Carbon of the soil, making it enriched in nutrients. The presence of these and other beneficial microbes in Nurture Growth biofertilizer plays a vital role in various nutrient cycling processes, making essential nutrients more available to plants. This enhanced nutrient availability supports healthier plant growth, leading to improved yields and overall productivity.

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Conclusion

The interaction between plants and microorganisms is crucial in regulating ecosystem processes, particularly nutrient cycling. Plants require a continuous supply of nutrients for their growth and development, which depends on the efficient movement of these nutrients from the soil to the plant and back into the ecosystem. Soil microorganisms are the essential component of this cycle, as they regulate nutrient availability and maintain soil health. (2)

Microorganisms play a crucial role in regulating nutrient cycling within the soil ecosystem. As key contributors to sustainable agriculture, they enhance the availability of essential nutrients, promote plant growth, and support overall plant health. By reducing reliance on chemical fertilizers, these beneficial microbes help maintain soil fertility, enhance soil structure, and increase crop productivity in an environmentally sustainable manner. (9)

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Topic: The Role of Microbes in Nutrient Cycling

Blogger Biography:

Dr. Ankita Garkoti is a Senior Science Officer at Nurture Growth Bio Fertilizer. She has over 9 years of experience in Agriculture research and extension. Her areas of specialization encompass Plant Pathology, Microbiology, Plant Protection, Organic farming, Biofertilizers, Organic Fertilizers, and Biocontrol agents.

She holds a Ph.D. in Plant Pathology and a master's degree in Botany with a specialization in Plant Pathology. Her doctoral research involved an in-depth study of lentil wilt and its management through various practices. She has extensive experience in organizing training programs on Organic and Natural farming techniques for farmers, agricultural growers, students and other stakeholders.