Role of Diazotrophs in Maintaining Soil Health and Factors Affecting their Growth and Development

Abstract

Soil microorganisms are pivotal to the health and productivity of terrestrial ecosystems, playing critical roles in soil structure, nutrient cycling, and plant growth. This paper explores the multifaceted contributions of soil microbes, including bacteria, actinomycetes, fungi, cyanobacteria, and protozoa, which populate fertile soils in vast numbers. They drive nutrient cycling through mineralization, converting organic matter into plant-available forms of carbon, nitrogen, phosphorus, and sulfur. Nitrogen fixation, both symbiotic (e.g., Rhizobium in legumes) and free-living (e.g., Azotobacter in cereals), provides a natural nitrogen source, reducing reliance on synthetic fertilizers. Additionally, microbes promote plant growth by synthesizing phytohormones, solubilizing phosphates, and producing siderophores, while also enhancing stress resistance and suppressing pathogens through competition and antibiosis. However, agricultural practices such as heavy nitrogen fertilization, pesticide use, tillage, and monocropping can disrupt microbial communities, diminishing their efficacy. This comprehensive analysis underscores the indispensable role of soil microorganisms in maintaining productive and resilient agroecosystems. This paper explores the multifaceted roles of soil microbes, emphasizing their importance in agriculture and environmental sustainability.