Automated Irrigation Schedule


I wish to program an automated irrigation schedule, based on the depletion of the Readily Available Water. I want the irrigation to resume every time the RAW is depleted by a 50% percentage. However, I wish the water applied through irrigation, not to exceed the Field Capacity (FC). Could you please inform me on the type of the irrigation strategy, that I should follow to achieve the above program?

Best regards,

Readily available water is not currently used but may be in the future. This can be converted into totavl available water (TAW_ which is used in the current irrigation schedulign methods (