Key Microorganism: Nematodes
Also known as roundworms, Nematodes are microscopic snake-like organisms are quite large in comparison to bacteria. Bacterial-feeding nematodes and fungal-feeding nematodes are key micrograzers for nutrient cycling in living soil. They are responsible for a significant portion of soluble nutrient release from bacteria and fungi. They indicate healthy aerobic conditions, especially in the case of fungal-feeding nematodes, whose numbers typically increase with peak soil health. Predatory nematodes are also beneficial due to their role in regulating pest larvae and parasitic nematodes (root-feeders) in the soil. Great care is taken to properly identify and separate each group for reporting.
Minimum populations of beneficial nematodes necessary are 100 per gram of soil (bacterial-feeders, fungal-feeders and predators).