Electric power supply kit adapted to be mounted with an irrigation system for land, said irrigation system comprising at least one conduit (110, 111) adapted for the passage of an irrigation fluid and at least one electrical device comprising at least one rechargeable power supply battery, said electric power supply kit comprising at least one hydroelectric turbine in fluid communication with said irrigation fluid adapted to generate an alternating electric current voltage as said irrigation fluid passes into said at least one conduit (110, 111), wherein said at least one hydroelectric turbine comprises a rotating element comprising a multiplicity of blades, at least one voltage regulator adapted to be powered with said alternating electric current, adapted to stabilize said alternating electric current voltage in a direct electric current voltage, and adapted to supply said at least one power supply battery of said at least one electrical device with said direct electric current voltage, at least one nozzle which is engaged inside said at least one conduit (110, 111) upstream of said rotating element, wherein said at least one nozzle is adapted to convey said inlet fluid of said at least one conduit (110, 111) towards a portion of said rotating element comprised between two adjacent blades so that at least one portion of said rotating element is in fluid communication with said at least one conduit (110, 111), wherein said at least one nozzle has a truncated-conical shape and comprises an inlet through opening and an outlet through opening, wherein said inlet through opening has substantially transverse dimensions equal to an internal cross section of said at least one conduit (110, 111), wherein said transverse dimensions are measured on a transverse plane lying on a geometric plane perpendicular to a rotation axis of said rotating element, wherein said outlet through opening of said nozzle has transverse dimensions equal to or less than an angular distance between two adjacent blades of said rotating element, wherein said angular distance between two adjacent blades is measured on an arc of a geometric circumference passing through ends of said blades, in which the geometric circumference comprising the arc comprises a geometric centre that is geometrically coincident with a geometric centre of the rotating element, characterized in that said truncated-conical shape of said at least one nozzle is truncated by a geometric curve which forms said outlet through opening, wherein said geometric curve comprises a cross section that follows the profile of said geometric circumference that passes through the ends of said blades. said irrigation system comprising at least one conduit (110, 111) adapted for the passage of an irrigation fluid and at least one electrical device comprising at least one rechargeable power supply battery, said electric power supply kit comprising at least one hydroelectric turbine in fluid communication with said irrigation fluid adapted to generate an alternating electric current voltage as said irrigation fluid passes into said at least one conduit (110, 111), wherein said at least one hydroelectric turbine comprises a rotating element comprising a multiplicity of blades, at least one voltage regulator adapted to be powered with said alternating electric current, adapted to stabilize said alternating electric current voltage in a direct electric current voltage, and adapted to supply said at least one power supply battery of said at least one electrical device with said direct electric current voltage, at least one nozzle which is engaged inside said at least one conduit (110, 111) upstream of said rotating element, wherein said at least one nozzle is adapted to convey said inlet fluid of said at least one conduit (110, 111) towards a portion of said rotating element comprised between two adjacent blades so that at least one portion of said rotating element is in fluid communication with said at least one conduit (110, 111), wherein said at least one nozzle has a truncated-conical shape and comprises an inlet through opening and an outlet through opening, wherein said inlet through opening has substantially transverse dimensions equal to an internal cross section of said at least one conduit (110, 111), wherein said transverse dimensions are measured on a transverse plane lying on a geometric plane perpendicular to a rotation axis of said rotating element, wherein said outlet through opening of said nozzle has transverse dimensions equal to or less than an angular distance between two adjacent blades of said rotating element, wherein said angular distance between two adjacent blades is measured on an arc of a geometric circumference passing through ends of said blades, in which the geometric circumference comprising the arc comprises a geometric centre that is geometrically coincident with a geometric centre of the rotating element, characterized in that said truncated-conical shape of said at least one nozzle is truncated by a geometric curve which forms said outlet through opening, wherein said geometric curve comprises a cross section that follows the profile of said geometric circumference that passes through the ends of said blades.