Mechanical linkage assembly for changing angle on disk drill closing wheel

An agricultural implement, comprising:

• at least one row unit closing wheel assembly, comprising:
• a closing wheel;
• a closing wheel arm;
• a closing wheel shaft having a first end and a second end, wherein the closing wheel is coupled to the first end and the closing wheel arm is coupled to the second end via a pivot joint;
• and
• an adjustable mechanical linkage assembly coupled both to the closing wheel shaft and the closing wheel arm, wherein the adjustable mechanical linkage assembly is configured to adjust an angle of the closing wheel shaft relative to the closing wheel arm along a horizontal plane via movement of the closing wheel shaft about the pivot joint, the horizontal plane being orthogonal to a rotational axis of the pivot joint, and wherein the adjustable mechanical linkage assembly is configured to adjust the angle between a plurality of set angle points relative to an initial set angle point.