Daily soil water potential readings of GMS are made in growers' fields by the grower or hired help and the readings are used to schedule irrigations. In Malheur County some growers use GMS in their own fields and the Soil Water Conservation District and Malheur County Extension Service monitors GMS in onion and potato fields, providing data to the growers. The cost is paid for by the growers with assistance from the Oregon Department of Agriculture. Six GMS are used to characterize the soil water potential in each field. Typically one area of a 16 ha field is chosen by the grower based on irrigation experience in prior years.
Field size varies.
Five of the six GMS are distributed widely across each area and each GMS is connected by up to 150 ft of 18 gauge insulated wire to a terminal strip. All sensors in a given area are wired to a single location for rapid reading. Responsive GMS placement has been determined. Sensors are read daily and the soil water potential data is plotted daily. The data is plotted for immediate interpretation and use by the grower.