Posted 3/20/2017 18:43 (#5912022 - in reply to #5911960) Subject: RE: Gallons of water per acre to equal an inch of rainfall
NW Washington
There are books written about irrigation and the water usage of various crops under various conditions. Evapotranspiration is the big word used for crop water usage.
And yes drip irrigation is much more efficient because much less water is lost to evaporation or run-off. Google is your friend. Check Drip Irrigation and crop evapotranspiration.