A device for treating soil has a soil contact head having at least one discharge orifice therein, and a handle to which the soil contact head is attached. A discharge valve is with the at least one discharge orifice, and a controller is provided for controlling operation of the discharge valve. An actuation trigger is included for initiating an injection event, with the controller being responsive to the actuation trigger to operate the discharge valve in response to the actuation trigger initiating an injection event. The controller controls the duration during which the discharge valve is open during an injection event in response to a single actuation of the actuation trigger. A source of pressurized fluid is flowably connected to the discharge valve, wherein the discharge valve is operable to discharge pressurized fluid through the at least one discharge orifice during an injection event.