Mention the types of nutrient cycling and explain them.

(A) Organisms require a constant supply of nutrients to grow,reproduce,and regulate various body functions.
The amount of nutrients,such as carbon,nitrogen,phosphorus,calcium,etc.,present in the soil at any given time is referred to as the $standing \ state$.
This amount varies in different kinds of ecosystems and also on a seasonal basis.
Nutrients are never lost from the ecosystem; rather,they are recycled time and again indefinitely. The movement of nutrient elements through the various components of an ecosystem is called $nutrient \ cycling$.
Another name for nutrient cycling is $biogeochemical \ cycles$ (bio = living organisms,geo = rocks,air,water).
Nutrient cycles are of two types: $(a)$ $gaseous$ $(b)$ $sedimentary$.
The reservoir for the $gaseous$ type of nutrient cycle (e.g.,nitrogen,carbon cycle) exists in the atmosphere,and for the $sedimentary$ cycle (e.g.,sulphur and phosphorus cycle),the reservoir is located in the Earth's crust.
Environmental factors,e.g.,soil,moisture,$pH$,and temperature,regulate the rate of release of nutrients into the atmosphere.
The function of the reservoir is to meet the deficit that occurs due to an imbalance in the rate of influx and efflux.