Harvested area of lettuces in Italy 2008-2019

The source adds the following information: "Crop statistics use the following definitions: For cereals, dry pulses, root crops, industrial crops and plants harvested green the areas refer to the area under cultivation. Area under cultivation means the area that corresponds to the total sown area, but after the harvest it excludes ruined areas (e.g. due to natural disasters). If the same land parcel is used twice in the same year, the area of this parcel can be counted twice.
For vegetables the area refers to the harvested area. For many vegetables the cropping time is short so the same area can be used several times per year. For this reason the harvested are can be much bigger than the physical area (main area).
For permanent crops the area refers to the production area. All non-productive areas are excluded (e.g. young non-productive plantations, abandoned areas, etc.).

The concept of "main area" used in main land use data corresponds, in general, to the area of the land parcel. The crop/occupation linked to that area is the unique or main crop having occupied the parcel during the crop year. In the case of annual crops, the main area should correspond to the sown area.
For permanent crops it refers to the to the total planted area (including non-productive plants). In the case of successive crops (mostly vegetables) it refers to the main crop that occupied the parcel during that year. These special cases are described in detail in the Handbook (Annual Crop Statistics Handbook in Annex 1)."