A clutch arrangement for a particulate chemical meter for use in a planter includes an axially and rotationally moveable shaft having a coupler on a first end and a knob on a second end thereof. The clutch shaft is inserted through and coupled to a chain-driven sprocket and sprocket sleeve combination. A coiled spring disposed about the shaft urges the shaft toward and in engagement with a dispensing rotor of the chemical meter for dispensing an insecticide or herbicide. Rotation of the knob in a first direction causes a roll pin inserted through the shaft of the clutch to ride up a cam surface disposed on an end of the sprocket sleeve for axially displacing the clutch shaft and disconnecting it from the rotor. Further rotational displacement of the knob positions the shaft roll pin in a notch also disposed on the end of the sprocket sleeve for maintaining the clutch disengaged. Rotational displacement of the knob and clutch shaft in a second, opposed direction permits the roll pin to slide down the cam surface under the urging of the coiled spring for automatically engaging the clutch when the planter is moved and the sprocket is displaced in the second direction of rotation.