Soil microbiology is the study of microorganisms in soil, including bacteria, fungi, archaea, protozoa, and viruses. These microorganisms play a crucial role in nutrient cycling, decomposition of organic matter, and overall soil fertility. Soil microbiologists also study the interactions between microorganisms and plants, as well as how soil microbial communities respond to environmental changes, such as climate change or pollution. Understanding soil microbiology is important for sustainable agriculture, ecosystem health, and biodiversity conservation.