AE792 Irrigation Scheduling by the Checkbook Method, Updated and Revised
Over the last 45 years, research into developing methods to optimally irrigate to conserve water and energy without sacrificing yields has been pursued worldwide.
Over the last 45 years, research into developing methods to optimally irrigate to conserve water and energy without sacrificing yields has been pursued worldwide. This research area is typically referred to as irrigation scheduling. Although many methods have been developed, according to the 2013 Farm and Ranch Irrigation Survey conducted by the National Agricultural Statistics Service (NASS), 80% of irrigators use either the crop appearance or soil moisture by feel methods to determine when to irrigate. Both of which are low tech and been used for many years. Why do irrigators prefer these two methods? Because they can generally be done at any time of the day, do not take a lot of time to perform and can easily be incorporated into the busy schedule of a farmer.
Irrigations can also be scheduled by tracking soil water amounts throughout the season, a soil water accounting method. This is often referred to as the “Checkbook Method”, which by the way was a term first coined in the original 1976 version of AE792 written by Darnell Lundstrom and Earl Stegman. The term “Checkbook Method” is now used worldwide and everyone knows it is a soil water accounting method. As presented in AE792, the checkbook method is easy to implement and can be done any time of the day. To setup the checkbook, all you need is the water holding capacities of the soil in your field, the crop type and an estimate of crop water use.
The soil water holding capacity by depth in your field is readily obtainable from the NRCS’s Websoil Survey website. Daily crop water use estimates are contained in tables in the publication. All you need to know is the crop type, the number of weeks past emergence and the high temperature for the day.
When used throughout the growing season, the checkbook method has been tested in many research studies and proven to be a reliable and accurate method of irrigation scheduling. The first version of AE792 was printed in 1976, reprinted in 1983 and revised in 1988. My colleague, Dean Steele and I have revised and updated the 1988 version.
Printed copies of AE792 can be obtained from any county Extension office or a pdf copy can be found online at https://www.ag.ndsu.edu/publications/crops/irrigation-scheduling-by-the…
NDSU Extension Agricultural Engineer
This site is supported in part by the Crop Protection and Pest Management Program [grant no. 2017-70006-27144/accession 1013592] from the USDA National Institute of Food and Agriculture. Any opinions, findings, conclusions, or recommendations expressed are those of the website author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.