The illustration that represents the largest reservoir of nitrogen on earth should display the atmosphere. The atmosphere of earth contains around 78.09 % nitrogen.
Ground water
groundwater. Snow and ice are the biggest but they aren't very available
The Shasta Reservoir
the largest reservoir in California is the Hoover dame wich is in Arizona.
Marina Reservior
The largest reservoir near Las Vegas is Lake Mead.
The soil and ground is the largest reservoir to store ammonia.
Lake Kariba in Zambia is the largest water reservoir on earth and runs 43cubic miles
The soil and ground is the largest reservoir to store ammonia.
Rocks
The atmosphere.