How to Pause ParticleSystem on Jump?

I am trying to pause my particle system when the player jumps then resume it when the player is grounded. When I run the game I get this weird error (NullReferenceException: Object reference not set to an instance of an object UnityEngine.ParticleSystem.Play (Boolean withChildren) (at C:/BuildAgent/work/d3d49558e4d408f4/artifacts/EditorGenerated/ParticleSystemBindings.cs:716) ManControllerScript.FixedUpdate () (at Assets/Scripts/ManControllerScript.cs:46)) and the player fails to jump and falls to his death. Here is my code and a screenshot of my hiearchy. Thanks in advance :)

 public class ManControllerScript : MonoBehaviour 
 {
 
     [SerializeField] float maxSpeed = 10f;                // The fastest the player can travel in the x axis.
     [SerializeField] float jumpForce = 700f;            // Amount of force added when the player jumps.    
     
     [Range(0, 1)]
 
     [SerializeField] bool airControl = false;            // Whether or not a player can steer while jumping;
     [SerializeField] LayerMask whatIsGround;            // A mask determining what is ground to the character
     
     Transform groundCheck;                                // A position marking where to check if the player is grounded.
     float groundedRadius = .2f;                            // Radius of the overlap circle to determine if grounded
     bool grounded = false;    
     Transform ceilingCheck;    
     float ceilingRadius = .01f;                            // Whether or not the player is grounded.
     Animator anim;                                        // Reference to the player's animator component.
     
     bool doubleJump = false;
     bool jumped = false;
     public ParticleSystem dirt;    
     
     void Awake()
     {
         // Setting up references.
         groundCheck = transform.Find("GroundCheck");
         ceilingCheck = transform.Find("CeilingCheck");
         anim = GetComponent<Animator>();
     }
     
     void FixedUpdate()
     {
         // The player is grounded if a circlecast to the groundcheck position hits anything designated as ground
         grounded = Physics2D.OverlapCircle(groundCheck.position, groundedRadius, whatIsGround);
         anim.SetBool("Ground", grounded);
         
         // Set the vertical animation
         anim.SetFloat("vSpeed", rigidbody2D.velocity.y);
         
         if(grounded){
             jumped = false;
             doubleJump = false;
             dirt.Play();
         }
     }
     
     
     public void Move(float move, bool crouch, bool jump)
     {
         
         //only control the player if grounded or airControl is turned on
         if(grounded || airControl)
         {
             
             // The Speed animator parameter is set to the absolute value of the horizontal input.
             anim.SetFloat("Speed", Mathf.Abs(move));
             
             // Move the character
             rigidbody2D.velocity = new Vector2(move * maxSpeed, rigidbody2D.velocity.y);
         }
         
         // If the player should jump...
         if ((grounded || !doubleJump) && jump) {
             // Add a vertical force to the player.
             anim.SetBool("Ground", false);
 
             dirt.Pause();
             dirt.Clear();
             
             rigidbody2D.velocity = new Vector2(rigidbody2D.velocity.x, 0);
             
             rigidbody2D.AddForce(new Vector2(0f, jumpForce));
 
             jumped = true;
             
             if(!grounded && jumped){
                 doubleJump = true;
             }
         }
 
     }
 
 }

.... and here's the hiearchy: