A hydraulic fluid manifold system for a spreader, the spreader including at least one bin for holding dry bulk material for distribution to at least one conveyor associated with the bin for receiving the dry bulk material from the at least one bin and transporting the dry bulk material to at least one spinner associated with the spreader. The hydraulic fluid manifold system includes a single, unitary manifold including a variable speed fluid control circuit for setting a speed for the at least one conveyor and a variable speed fluid control circuit for the at least one spinner of a spreader system for setting a speed for the at least one spinner, the variable speed control circuit for the at least one conveyor including an on/off device for the at least one conveyor that allows when fluid flow through the variable speed conveyor circuit to the at least one conveyor is turned on that the at least one conveyor can automatically operate at a speed set for the at least one conveyor prior to fluid flow to the at least one conveyor having been turned off. Further, the spreader can include at least two conveyors, and the variable speed control circuit for the at least two conveyors can further include flow of hydraulic fluid through the variable speed conveyor circuit to be changed between in-parallel flow to a first and a second of the conveyors simultaneously and in-series flow where flow of fluid is sent to a first one of the conveyors and then sent from the first one of the conveyors to a second one of the two conveyors.
