A protective device of a dispenser supply hose comprising a trolley (4) which is movable on a soil (200) to be irrigated, which trolley (4) can be associated with a supply hose (2) of a fluid (100); said device further comprises a protective element (9) intended for said supply hose (2), which protective element (9) is interposed between the soil (200) and said supply hose (2), and accumulating means (8) of the protective element (9) suitable for extending said protective element (9) during an extension step of said supply hose (2) and to recover said protective element (9) from said soil (200) during a recovery step of said supply hose (2).