The simplest of all nutrient cycles operating in an ecosystem is .......... cycle.

The simplest of all nutrient cycles is phosphorus cycle as it exists in only one form and that is phosphate. Phosphorus is present either as a part of an organism, dissolved in water or in the form of rock and never makes its way into the atmosphere. The rocks with phosphate on coming in contact with water containing little acid undergo weathering and thus phosphorus goes into solution. Plants take this phosphorus through their roots and utilize it in various ways.