1. Evapotranspiration In Golf Courses
By: Tyler Shrum

2. What Is Evapotranspiration
Evapotranspiration (ET) is a measurement of the total amount of water needed to grow plants and crops. This term comes from the words evaporation (i.e., evaporation of water from the soil) and transpiration (i.e., transpiration of water by plants). Different plants have different water requirements, so they have different ET rates. (

3. Who Cares???
With continued drought and increasing populations, water is becoming more scarce each year.
Turf and Irrigated crops, water is extremely overused because of job security and the ignorance to adapt to new practices.

4. How to Calculate ET Penman or Penman-Monteith Method
ETo x Tc x Qf = turf water requirement
Quality Factor (Qf)
Turf Coefficient Values (Tc)
Warm Season
0.6
Cool Season
0.8
No Stress
1.0
Low Stress
0.8
Normal Stress
0.6
High Stress
0.5
Very High Stress
0.4

5. Stacking Stacking Find A Threshold for watering
Based on Soil Type, Humidity, Wind, Plant Type
Spread out water date so one waters Deeply and Infrequently
Add up ET readings over a period of days and multiple by the crop or Turf Coefficient
Note that the turf coefficient is different at every site and one must experiment to find a proper Tc for there area

6. Things to Consider Microclimates
Mesonet readings are a good reference but people should really have localized weather stations to determine exact conditions at their site
Generally Speaking, a well irrigated golf course/turf setting will be 5 degree F lower than surrounding areas

7. Technology
Soil Probe
Still the best way to monitor Soil Moisture to implement a BMP (best management practice)

8. Centrals The Nimbus™ II Central Control System
“Minimum ET™ is another new feature that helps promote healthy turf by supporting advanced ET management techniques. With the Minimum ET feature a superintendent can define a minimum ET threshold value that must be met before irrigation will take place. Minimum ET values can be assigned globally so they affect all programs, or individually by programs for the ultimate in ET management.” (rainbird.com)

9. Possibilities? “Smart Dust”
Tiny wireless microelectromechanical sensors (MEMS) that can detect everything from light to vibrations
Possibility of being able to scatter hundreds of tiny sensors around a building or golf course to monitor temperature or humidity

10. Possibilities???
Use of Valve in Head or Layout of pipes to help measure soil moisture level, and design grid based on Layout

11. Questions????