*All links were available and accurate as of November 22, 2013.*
Northern Great Plains Research Laboratory
United State Department of Agriculture - Agriculture Research Service (USDA-ARS)
A crop water use/evapotranspiration calculator for South Dakota linked to weather data
South Dakota State University
An extension article on crop water use and evapotranspiration
Iowa State University
Extension article on "When Necessary, Just in Time, Irrigating Can Save Water"
Emphasizes crop water use and critical crop growth period concepts; Montana State University
Extension publication on crop water stress during critical growth periods and crop water use
Colorado State University
What is ET? An Evapotranspiration Primer
Kansas State University