Horticulture: July 2008

In the March 2007 edition of Ag News & Views, I highlighted a few of the agriculture decision-making support tools available on the Oklahoma AgWeather Web site.

Recently, Al Sutherland, OSU Mesonet agriculture coordinator, introduced me to another tool the folks at Mesonet have developed to assist homeowners and professional groundskeepers. This new tool, known as SIP, "Simple Irrigation Plan," was created to answer the most commonly asked questions when it comes to irrigating turfgrass. When should I water? How long should I run it?

SIP uses data from the Oklahoma Mesonet to estimate turfgrass water use. This takes the guesswork out of when and how long to water a lawn. By replacing only the water lost through evapotranspiration, overwatering can be minimized, thereby reducing waste and saving you money.

To use SIP, go to sip.mesonet.org. Click on one of the three options: Simple Watering, Advanced Watering or Advanced Watering +. The Simple Watering option is the easiest and quickest to use and was developed with the average homeowner in mind. The advanced options provide more accurate watering recommendations because additional information including soil type, soil slope and level of lawn care are used to calculate a recommendation.

The Simple Watering option consists of four steps. In step one, select the Mesonet site closest to you. Your local Mesonet weather station records the air temperature, relative humidity, wind speed and sunlight specific to your location and uses the information to calculate the evapotranspiration rate for your location.

In step two, indicate how many days ago you last watered.

In step three, select a grass type. The options available are bermudagrass, zoysiagrass and fescue. If you have a St. Augustine lawn, select zoysiagrass as both have similar water requirements.

In step four, select your sprinkler type. The common types for automatic systems and hose-end sprinklers are listed. Are you clueless about the name of your sprinkler? Not to worry; the sprinkler types are also listed by picture.

Based on your inputs, SIP calculates a time range to operate your sprinkler. Plan on watering at the high end of the watering run time if the lawn is new, stressed from high traffic or when you want the turf to look its best.

Another nifty feature of SIP is the water cost calculator. Simply enter the number of moves you make with a hose-end sprinkler or the number of sprinkler heads in your automatic system and the cost rate charged by your municipality or water district. SIP calculates a cost for the specified run time.

SIP is the latest example of how the folks at Oklahoma State University and the University of Oklahoma are using weather data from the Oklahoma Mesonet to develop real-world tools for all Oklahomans.

For more detailed information on the use of SIP, call Al Sutherland at (405) 325-3463, or e-mail him at albert.sutherland@okstate.edu.