Summary:  When making decisions about when to irrigate a crop, no matter the specific plant or scenario, it is important to take into consideration evapotranspiration rates which provide an estimate of water flux out of your system.  The challenge is that evapotranspiration varies a lot depending on the specific plant, its growth stage plus changing weather (or greenhouse) conditions. Precision agriculture scientists have been able to characterize two reference crop values as a way to standardize evapotranspiration calculations based on weather data. In this lesson you will learn what is meant by a reference crop, crop coefficient, and water stress coefficient and how you can use these to inform your irrigation management decisions.   

Time Required: We estimate it will take you 2 hours to complete the lesson.  You can work on it at your own pace and do not have to complete it in one setting.

Who Would Benefit:  A variety of people will find this upskilling course useful from adults to high school students.  This includes careers (or hobbyists) growing plants (ie field crops, greenhouse production, turf and lawns, gardens, etc.) and wishing to save money and water by better timing irrigation applications.

Upskill Credentials: If you finish the entire course including passing a final quiz (which you can take up to 3 times), then you will earn a badge certificate of completion.  It has been approved for 2 Soil and Water Management CEUs through the national Certified Crop Adviser program.

Instructor: Dr. Allan A. Andales is a Professor and Extension Specialist of Irrigation and Water Science in the Department of Soil and Crop Sciences, Colorado State University (CSU). He has a joint appointment in the Department of Civil and Environmental Engineering. Dr. Andales applies principles of soil and water engineering, environmental biophysics, and numerical methods to study the effects of management practices and environmental factors on field hydrology and agricultural production. Experimental data are used to develop computer models and decision support tools that can improve agricultural water use efficiency and water quality. He is a member of the CSU Extension Water Resource Management Team that engages the public in addressing agricultural and urban water issues in Colorado.

ADA Accessibility: We have done our best to follow ADA best practices. Let us know if you run into any problems or require further accommodations.

Acknowledgements: This online micro-credential upskilling course is offered through the CSU Ag Upskilling program.  Development was supported in part by funding from the CHS Foundation, administered by Colorado State University (2022).  The CHS Foundation, funded by charitable gifts from CHS Inc., is focused on developing a new generation of agriculture leaders for life-long success. Together, with our partners, we are igniting innovation and driving excellence in agriculture education, cultivating high impact programs for rural youth and accelerating potential for careers in agriculture.  Learn more at CHS Foundation.