Abstract: A mobile treatment system for subterraneously aerating and stimulating root zones with a probe. Suitable controls enable the operator to mix liquid root stimulator solution within a storage tank, and then pump it into the ground through the probe. A motor-driven air compressor controls a pneumatic holding tank to store pressurized air. The multi-segmented probe has a rigid, upper segment that receives liquid through a check valve, an intermediate segment receiving high pressure air, and a lowermost section extending downwardly from a foot plate and terminating in a hardened point. Output orifices defined in the tip deliver air or solution subterraneously. A controller circuit times an injection cycle upon actuation of a probe-mounted switch by actuating a solenoid valve for metered fluid injection. When the injection cycle completes, a manual valve on the probe can be opened for aeration.