Interactive Irrigation Scheduling Worksheet using Current and Historical Evapotranspiration
Vineyard Irrigation Scheduling Worksheet (Interactive)
This worksheet provides the means to calculate the amount of water to apply in a winegrape vineyard based on the deficit irrigation strategy fully detailed in the publication "Deficit Irrigation of Quality Winegrapes Using Micro-Irrigation Techniques", by UC Irrigation and Water Management Specialist Terry Prichard, et. al.
Vineyard water use is driven by atmospheric factors that include solar radiation, air temperature, vapor pressure and wind speed. These and other variables are measured and used as terms in a model that calculates relative water demand known as reference evapotranspiration (ETo).
Regulated deficit irrigation (RDI) strategies are commonly employed in winegrape vineyards to reduce irrigation volume from approximately 35% to 60% of full potential water use to reduce water consumption, control vegetative growth and improve fruit and wine quality.
The UCCE Sonoma Vineyard Scheduling Irrigation Worksheet is designed to simplify irrigation scheduling by performing the necessary calculations utilizing historical ETo data (provided) coupled with user-selected vine density, emission uniformity, available soil moisture and RDI strategies.
Historical ETo data for selected locations are incorporated into the worksheet. However, users must log on to either the CIMIS or UC IPM websites to obtain current-year evapotranspiration data to compensate for differences between historical and actual water demand by location.
Maximizing water use efficiency requires evaluation of drip system emission uniformity. A worksheet to calculate Emission Uniformity is located in the page "Drip System Evaluation" on this web site.