As carbon and energy flow through the soil food web they are depleted by the metabolic and production functions of organisms. To be sustained, a “long” food web, with a large biomass at higher trophic levels, must receive a high rate of rhizodeposition or detrital subsidy, or be top-populated by organisms of slow growth and long life cycle.
Nematodes are wormlike organisms which can be seen with naked eye, live in water-filled pore spaces in the soil. Nematodes are in large number in the upper soil layers where organic matter, plant roots, and other resources are most abundant.
The functions of nematodes:
Free-living nematodes decompose organic material into nutrients and cycled them in the soil by feeding on some bacteria and fungi.
Nematodes help in distributing bacteria and fungi through the soil and along roots by carrying live and dormant microbes.
They used as food for higher predators, soil microorthropodes.
They eat disease-causing organisms, thus suppress their growth.
