Summary: Irrigation is defined as the watering of land (or other plant growth media) by artificial means to foster plant growth. This can be very costly and the availability of supplemental water may be scarce, so it is important to be able to calculate accurately how much water to apply and when. This lesson will introduce you the underlying concepts you will need to consider.

After completing this lesson, you will be able to:

• Explain how the systems approach can be used to manage water in irrigated systems. 
• Identify the fluxes (flows) of water and energy in an irrigated soil-plant-atmosphere system.
• Describe how the Irrigator’s Equation can be used to quantify the four (4) major variables involved in managing irrigation systems.
• Use the principle of conservation of mass to determine the water budget (also called water balance) of a soil-plant-atmosphere (SPA) system. 
• Use the principle of conservation of energy to determine the energy budget (also called energy balance) of a SPA system.

Time Required: We estimate it will take you 2 hours in total 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.  This has also 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.

Summary: To effectively utilize limited irrigation resources in the most cost-effective manner requires balancing the inputs and outputs of water fluxes, as well as water that is stored in the soil profile. Best irrigation management scheduling practices focus on water balance in the rootzone because that is where the plant/crop is extracting water (and nutrients) from the soil.  It is here we estimate the irrigation water requirements to maintain healthy plants. Decisions on when and how much irrigation water to apply depends on the soil water deficit and the management-allowed depletion (MAD). This lesson will walk you through each of these concepts including real world problem scenarios.

After completing this lesson, you will be able to:

• Use the water balance of the root zone to estimate the irrigation water requirement. 
• Make irrigation decisions by comparing the soil water deficit to the management-allowed depletion. 
  
  

Time Required: We estimate it will take you 2 hours in total 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.  This has also 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.