An axial flow rotary valve for an engine, that is rotatable about an axis within the bore of a cylinder head. The agglomerates may be used as a soil liming agent and for introducing nutrient values into cultivated soil. Supporting portions abutting against the tray operation portions inherent to respective trays in one to one correspondence are fixed with an interval in the vertical direction to the frames configuring a tray distributingholding portion. The substantially rigid rotor is in fluid communication with the pressurized air source. The DC offset calibration circuit is coupled to the post-stage circuit and utilized for providing at least a compensation current for the post-stage circuit to reduce DC offset of the output signal. This specific data constrained analytic algorithm performs the appropriate type of data analysis on the appropriate data source in order to generate an analytic result, which is transmitted to the user.