Microorganisms play a crucial role in the nutrient cycle by decomposing organic matter, such as dead plants and animals, into simpler compounds like carbon dioxide, water, and nutrients. This process, called decomposition, releases nutrients back into the soil, making them available for uptake by plants and other organisms, thus sustaining life. In the conversion of agricultural wastes to compost, various microorganisms are involved, including bacteria, fungi, and actinomycetes. Bacteria, such as Bacillus and Pseudomonas species, break down complex organic materials into simpler compounds. Fungi, like Aspergillus and Penicillium species, aid in the decomposition of tougher materials, like cellulose and lignin. Actinomycetes help break down organic matter into smaller particles. Together, these microorganisms transform agricultural wastes into nutrient-rich compost, which can then be used to improve soil fertility and support plant growth.