A method, using an autonomous, unmanned device and a control device, includes the steps of automatically harvesting feed crop in a part of a crop field by means of the autonomous, unmanned device; automatically loading the harvested feed crop directly into a storage space provided on the autonomous, unmanned device without said harvested feed crop contacting the soil; choosing a destination location from a feeding location and a stationary crop processing location; automatically transporting the harvested feed crop from the crop field to the chosen destination location by means of the autonomous, unmanned device; and automatically unloading harvested feed from the storage space of the autonomous, unmanned device at the chosen destination location.