Nitrogen is an element found naturally in the atmosphere and its cycle refers to the way in which nitrogen and the compounds of nitrogen are transformed. The role that plants play during the cycle is an important one. Plants consume nitrogen in the form of Nitrates. Nitrogen gets converted into nitrates by the denitrifying bacteria. These plants absorb nitrogen in the form of nitrates through the groundwater. These plants are then consumed by the animals as food. In the cycle, the plants and animals decompose after their death hence becoming a source of Ammonium.