Select the sources you wish to copy from the setup dialog and choose the plan years to copy to. If you check Overwrite existing sources with the same name, then any existing manure production sources in the destination years with the same values for Animal Type and Size, Subfarm, Barn name, Present In Winter and similar % collected or Pits and Spreaders with the same name will be changed to have the new data. Otherwise, manure production sources that are not similar and Pit and Spreader names that do not exist will be added to the selected plan year.