Untitled

graph TD
    A[Atmospheric Nitrogen N2] -->|Nitrogen Fixation by Bacteria| B(Ammonia NH3);
    B --> C(Nitrites NO2-);
    C --> D(Nitrates NO3-);
    D --> E[Plants];
    E --> F[Animals];
    F --> G[Decomposition];
    G --> B;
    D -->|Denitrification by Bacteria| A;

    style A fill:#f9f,stroke:#333,stroke-width:2px
    style B fill:#ccf,stroke:#333,stroke-width:2px
    style C fill:#ccf,stroke:#333,stroke-width:2px
    style D fill:#ccf,stroke:#333,stroke-width:2px
    style E fill:#cfc,stroke:#333,stroke-width:2px
    style F fill:#ffc,stroke:#333,stroke-width:2px
    style G fill:#fcf,stroke:#333,stroke-width:2px

    %% Labels for bacteria involvement
    click A callback "Nitrogen-fixing bacteria: Rhizobium, Azotobacter"
    click B callback "Nitrifying bacteria convert ammonia to nitrites"
    click C callback "Nitrifying bacteria convert nitrites to nitrates"
    click D callback "Denitrifying bacteria: Pseudomonas, Clostridium"