I have tables (marks,students,subjects,courses) marks belongs to (students,subjects,courses) and i inserting data in marks using foreach method here is my inserting controller method

my controller

public function postmarkForm($reg_no = null,Request $request)
    {

    	$s = Student::where('reg_no',$reg_no)->with('courses','courses.psubjects')->first();    
    	$course_id = $s->courses->id;   
    	$datetime = Carbon::now();
    	foreach ($s->courses->psubjects as $sub)
    	 {    	 
    		$data = [
                 
                 'course_id'  => $course_id,
                 'subject_id' => $sub->id,
                 'test_marks' => $request->rows[$course_id]['test_marks'],
                 'mid_marks'  => $request->rows[$course_id]['mid_marks'],
                 'end_marks'  => $request->rows[$course_id]['end_marks'],
                 'student_id' => $s->id,
                 'updated_at' => $datetime,
                 'created_at' => $datetime,

    			];
             dd($data);
    			Mark::create($data);
    	}

    	return back();
    }

my view

<form method="post" action="/acadmic/{{$s->reg_no}}/marks_upload" data-parsley-validate ="">
        {{ csrf_field() }}
      <table class="table table-bordered  table-hover">
      	<thead>
      		<tr>
      			<th  style="text-align: center;">Subject</th>
      			<th  style="text-align: center;">Test Marks</th>
      			<th  style="text-align: center;">Mid Marks</th>
      			<th  style="text-align: center;">End Marks</th>
      		</tr>
      	</thead>
      	@foreach($s->courses->psubjects as $subject)
      	<tbody>
     		<tr>    		
      			<td class="col-md-3" >      				
			      	 <div class="form-group" >       
			          <select  class="form-control" id="{{ $subject->id }}_subject"  name="rows[{{ $subject->id }}][subject]" required="">
			          <option value="{{ $subject->id}}">{{ $subject->name }}</option>
			          </select>
			         </div>			       
      			</td>     	      		
      			<td class="col-md-3">      				
			      	<div class="form-group">              
			         <input type="text" class="form-control"  id="{{ $subject->id }}_test_marks"  name="rows[{{ $subject->id }}][test_marks]" data-parsley-type="number">
			        </div>			      
      			</td>
      			<td class="col-md-3">     				
			     	<div class="form-group">             
			        <input type="text" class="form-control" id="{{ $subject->id }}_mid_marks" name="rows[{{ $subject->id }}][mid_marks]" data-parsley-type="number">
			       </div>			   
      			</td>
      			<td class="col-md-3">     				
			     	 <div class="form-group">             
			         <input type="text" class="form-control" id="{{ $subject->id }}_end_marks" name="rows[{{ $subject->id }}][end_marks]" data-parsley-type="number">
			         </div>			      
      			</td>
      		</tr>
      	</tbody>
      	@endforeach
      </table>
                   
     <div class="col-md-4 col-md-offset-4">
     <br>
     	<button type="submit" class="btn btn-primary btn-lg btn-block">Submit</button>
     </div>     
    </form>

my marks table

Schema::create('marks', function (Blueprint $table) {
            $table->increments('id');
            $table->integer('course_id')->unsigned()->index();
            $table->integer('subject_id')->unsigned()->index();
            $table->integer('student_id')->unsigned()->index();
            $table->float('test_marks')->nullable();
            $table->float('mid_marks')->nullable();
            $table->float('end_marks')->nullable();
            $table->timestamps();
        });

here is problem when i try submit the for my test_marks, mid_marks, end marks returning null here is dd($data)

array:8 [▼
  "course_id" => 3
  "subject_id" => 1
  "test_marks" => "600"
  "mid_marks" => "500"
  "end_marks" => null
  "student_id" => 4
  "updated_at" => Carbon {#443 ▶}
  "created_at" => Carbon {#443 ▶}
]