Potlatch Tree Farm Control architecture providing automatic as well as manual control for all irrigation, fertilization and pumping functions at a 36-square-mile Potlatch Corporation tree farm near Boardman, Oregon has produced benefits exceeding original goals. The automated control system designed and provided by Programmable Control Services, Inc. provides operational data for analysis and diagnosis that competitors using largely manual control systems do not have. System information has allowed pump stations to run 10-20 psi lower than originally thought necessary. Irrigation cycles have been modified to reduce silt loading of emitters, and filtration improvements have been made based on the data that would otherwise not have been available. The project began when Potlatch Corporation needed to convert a huge farmland acquisition near Boardman on the Columbia River from a rotating pivot-sprinkler irrigation to a drip irrigation system in six phases. The rapid-growth hybrid poplar trees grown in each phase would supply Potlatch's nearby Lewiston, Idaho, paper mill with 25 percent of its annual pulpwood requirements. The project required standardized control architecture for 109 manifolds and 12 pump stations fielded incrementally over six years. Communications between the manifolds, pump stations and master stations use fixed frequency radios. All control hardware used is Allen-Bradley, with Windows graphical user interface software. PCS developed a common hardware configuration for the manifolds and a general configuration for the pump stations utilizing the Allen-Bradley SLC-5/03 and its related I/O. This yielded a simpler control architecture that reduces spare parts, drawings and training. During phase four, the single SCADA (supervisory control and data acquisition) master functions running on an Allen-Bradley PLC-5/40E were divided between a pump SCADA master and a manifold SCADA master. This allowed each to control separate dedicated radio networks with their slave units, thus increasing system expansion capabilities. Numerous add-on interfaces for the SCADA operator interface were developed by PCS as needed to assist in generating both two-week irrigation schedules for each manifold and fertilization schedules for each age-class of tree. The controls allow farm managers to minimize peak power excess demand charges, balance water usage, and efficiently operate the hydraulic and mechanical systems.