A continuous preparation of calcium hydroxide slurry can be made on a mobile apparatus that uses an eductor to initially combine metered flows of calcium oxide and water. An adapter is provided for mounting the grass treatment unit on the walk behind greensmower and another adapter is provided for connecting the grass treatment unit to the power source previously used by the cutting head. The stop mechanism further includes a second clutch assembly having a second roller clutch engaged to the steering shaft, a second rotary brake engaged to the second roller clutch and a second electrical connector connected to the second brake and in signal communication with the controller. The power spectrum includes a maximum peak. Each of the two NPC diodes corresponds to one of the at least two switches.