Major components of the hydraulic system for DREC no-till drill.  Though the drill is pulled on the lower two links of the three point hitch, the hitch remains level and the openers move up and down on their own.  The accumulators, shown in the upper left photo, equalize the pressure within the system.  The memory valves show in the lower right picture allow the openers to be lifted out of the soil at the end of a pass and then when the openers are set back into the soil this valve “dumps” the pressure of the system back into the openers so the pressure is the same as in the previous pass.  A load cell, not pictured, located on the center opener detects the degree of penetration the opener is experiencing.  A meter in the cab of the tractor provides information to the operator the amount of hydraulic pressure in the system as well as on the load cell.  The operator can make adjustments or a computer can do this automatically.