The 2009 ASHS Annual Conference

The Simple Irrigation Plan (SIP) Web site was created to provide a turfgrass irrigation decision support tool simple enough for consumers to use. The site uses the American Society of Civil Engineers standardized reference short crop evapotranspiration multiplied by individual coefficients for bermudagrass, zoysiagrass, and tall fescue. Turf coefficients are adjusted based on average daily temperature, rather than by calendar dates to make the turfgrass evapotranspiration rates more responsive to the highly variable Oklahoma weather. The Web site has three options for entering and receiving a watering time recommendation: “Simple Watering,” “Advanced Watering,” and “Advanced Watering Plus.” The primary goal of the "Simple Watering" option is to create a Web based decision support product consumers would use. Informal evaluation of existing Oklahoma Mesonet evapotranspiration models indicated there was a high interest by consumers for an online irrigation decision support tool, but that they would not use models that required: them to learn scientific terms and methods, them to record or add up data, them to interpret data from tables. The SIP Web site design and choices for "Simple Watering" were purposely pared down to provide the user an answer as fast as possible with as few inputs as possible. Sprinkler run times are reported in a range of minutes to account for variation in sprinkler watering rate. The “Advanced Watering” option provides a more precise sprinkler run time, but requires the user to enter more data about their irrigation and turfgrass situation. The third option, “Advanced Watering Plus,” offers users a way to save their inputs in “Advanced Watering” by getting a free account name and password. Evapotranspiration rates are based on weather data from Oklahoma Mesonet sites. This network has 120 sites, approximately 32 kilometers apart, across Oklahoma. All options include a water cost calculator with water costs for over 200 Oklahoma communities. Turfgrass and sprinkler choices are made by selecting from pictures to speed selection and avoid confusion in sprinkler selection.