Vol. 9, Issue 3, Part F (2025)

Soil DNA represents the genetic material of diverse soil organisms, serving as a crucial indicator of microbial diversity, ecosystem functions, and soil health. Soil security means protecting and managing soil to support healthy ecosystems, good crop growth, and a clean environment. By studying soil microbes through DNA analysis, we can detect problems and improve soil health. New molecular methods help restore degraded soils and ensure sustainable land use. Extracting DNA from soil involves direct and indirect methods, each with distinct benefits and limitations concerning yield, purity, and inhibitor presence. Direct methods, such as PEG/NaCl, bead beating, and mannitol-based protocols, isolate DNA directly from the soil matrix, while indirect methods rely on cultivating microorganisms prior to DNA extraction. The purity and quality of extracted DNA are essential and are evaluated through spectrophotometric ratios (A260/A280 and A260/A230). The Polymerase Chain Reaction (PCR) serves as a fundamental method in molecular biology, facilitating the amplification of targeted DNA regions such as 16S rRNA genes for identifying bacteria and ITS regions for characterizing fungi. PCR products are analyzed through gel electrophoresis and sequencing, enabling microbial identification and functional analysis. Despite challenges such as contamination and inhibitors, advancements in soil DNA extraction and amplification significantly enhance our ability to assess soil health, contributing to sustainable soil management and ecological security. This topic explores methods for soil DNA extraction, sequencing, and bioinformatics analysis, focusing on their use in tracking and improving soil health. The Mannitol-PBS-CTAB method stands out for its efficiency, delivering high DNA yields and purity (A260/230: 2.07; A260/280: 1.85), making it ideal for precise downstream applications. This method reduces contamination, ensuring high-quality DNA essential for PCR and sequencing. Such techniques are vital for profiling microbial communities, identifying beneficial microbes to enhance crop productivity, diagnosing soil degradation, and advancing ecological restoration, Soil security.