Changing value for features overlapping another feature in the same layer

You can use select by expression to select features on the same layer using the expression get_feature. The expression in this case is (see screenshot where the labels show the valule of the Seeding_Ra attribute for each polygon):

overlaps( 
    geometry (
        get_feature (
            @layer,
            'Seeding_Ra',
            33500 
        )
    ), 
    $geometry
)

You can thus use the following expression to update your attribute field Seeding_Ra (see result in the following screenshot, where the value of the Seeding_Ra has been updated to 33500 for polygons that overlap and has remained the same for all others):

if (
    overlaps( 
        geometry (
            get_feature (
                @layer,
                'Seeding_Ra',
                33500 
            )
        ), 
        $geometry
    ),
    33500,
     "Seeding_Ra" 
)