Improving vineyard water use efficiency and yield with variable rate irrigation in California

A variable rate drip irrigation (VRDI) system was implemented in early 2013 in a 4.05-ha area inside a drip-irrigated Cabernet Sauvignon vineyard measuring 12.5 total ha. The VRDI area was split into 140 15×15-meter irrigation zones which were watered independently during three seasons with weekly schedules based on estimated actual ET. Irrigation was scheduled with the objective of decreasing spatial variability while maintaining high yields. Compared to an adjacent, 4.05-ha, conventionally drip irrigated section of the vineyard (CDI); VRDI increased yield and water use efficiency in all three years and decreased spatial dependency and structure in 2013 and 2015.