Convert JSON to appropriate Format using Ember Serializer

I would like to convert the JSON object

{
 User:{
  'Name':"asdas",
  'Address_Line_1':"dasdasd"
  }
}

to form data

Name=asdas&Address_Line_1=dasdasd

before sending request to my API Server

P.S : I removed root element 'User' using serializeIntoHash method