- Fungi are microscopic cell structures that grow into thread-like strands called hyphae. There are more than 70,000 species of fungi, according to the Tree of Life Web Project. As they continue to grow, hyphae move through the particles, roots and rocks contained in the soil.
The larger species of fungi include molds, mushrooms, yeasts and truffles, according to the National Resource Conservation Service. Some varieties of hyphae grow together to form thick cords that look like roots. These root-like growths are called rhizomorphs, while growths like mushrooms and molds are considered fruiting, or fruit-like, structures. - Moisture content, nutrient metabolism and disease suppression are all affected by soil fungus activity, according to the National Resources Conservation Service. Organic materials must decompose before they become nutrients for the soil. Fungi organisms break down organic materials for use. Fungi bind soil particles together, enabling water to flow through channels throughout an ecosystem. Disease suppression is carried out by fungi that trap parasite organisms and engulf insects.
- Fungi are categorized according to the types of energy sources they use, according to the National Resources Conservation Service. Pathogens act much like parasites, as they colonize around plant root structures and feed on them. Mutualists also colonize around root structures, but offer an exchange of needed nutrients for carbon materials released by the roots. Decomposers work to break down dead organic organisms into organic acids and carbon-dioxide materials needed to nourish plant roots.
- Mycorrhizal fungi fall within the mutalist category, making them a vital component in plant-feeding soil environments, according to Better Hydro Gro. Many trees and agricultural crops rely on these organisms for their survival. There are, however, some plant types that are unable to interact with mycorrhizal fungi in this exchange of needed materials, which may affect how plentiful these fungi can become. Soil that is tilled frequently or contains high levels of nitrogen or phosphorous fertilizers may decrease mycorrhizal fungi growth rates.
- Too many fungus organisms can have a debilitating effect on soil and plant systems, according to University of California Museum of Paleontology. Pathogen fungi in particular can deplete needed nutrients from the root and plant structures, causing leaf, stem and root rot. Fungi are similar to other animal and plant organisms in chemical and genetic makeup, which makes them a more viable threat to plants, and animals as well. Soil environments that hold a high alkaline pH balance are most conducive to fungus growths.