Besides water, autotrophs require various essential materials for building their bodies. These include nutrients obtained from the soil, such as nitrogen, phosphorus, iron, and magnesium. Nitrogen, a crucial element, is utilized in the synthesis of proteins and other vital compounds. Autotrophs absorb nitrogen either as inorganic nitrates or nitrites from the soil or as organic compounds prepared by bacteria from atmospheric nitrogen. Phosphorus, iron, and magnesium are also essential for various biochemical processes and the formation of essential molecules within the autotrophic organism. The acquisition of these nutrients from the environment is crucial for sustaining their growth and development.