Systems Knowing when to irrigate a crop and how much water to apply is crucial during a drought.
Application efficiencies in the range of 80 to 85 percent are attainable for orchard drip, and application efficiencies of 75 to 85 percent are attainable for row crop drip systems. Local farm advisors can provide information on performing a system evaluation. If that happens, the MAD must be reduced. If the gross application is 0.53 inches and the application efficiency is 0.80, the net application and the management allowable depletion both equal 0.42 inches. Irrigations are therefore needed on the day before the date actual soil water depletion is expected to exceed 0.42 inches.