The main gripe for farmers is the mindnumbing clickfest that comes with harvesting crops.  I propose this method be changed into something similar to plowing with a plow so as to decrease the amount of clicks needed to harvest the crops.  Whether this requires an aditional tool or not, is not my concern; it may not be realistic, but it sure would make farming less boring and grindy.
Edit:  This would be great for sowing seeds too, or just shift-click planting instead <.<