The Drip Irrigation Calculator will help you calculate how many gallons of water to apply when using drip irrigation.
The Basic calculator assumes you will irrigate when 25% of the Available Water Holding Capacity (AWHC) is used. When an emitter spacing and flow rate is entered, it will also calculate run times. To use, enter the number of rows, feet of drip line per row, the rooting depth (in inches), and choose a soil type. Enter the emitter spacing (in inches), and the emitter flow rate (in gallons per minutes) to calculate run times.
The Advanced calculator works similar to the Basic calculator, except that it uses specific water holding capacities of any soil series found in Iowa. The Advanced calculator gives a range of gallons to apply and therefore a range of run times. Furthermore, you can adjust the percent of water depletion to any value.
To learn how these values are calculated, read "Irrigation Scheduling and Tensiometer Tips for Trickle Irrigation". Developed from "Irrigation Scheduling and Tensiometer Tips for Trickle Irrigation" by Dr. Hank Taber and from NRCS Soil Survey Data.
Article by Joseph M. Hannan, 2015