UC Davis

Precision mobile drip irrigation (MDI) describes the application of water through surface drip irrigation lines that are dragged by center pivot or linear move. MDI has the potential to greatly reduce water losses due to wind drift, soil water evaporation, and canopy evaporation. Two studies were conducted with the following objectives: (1) compare soil water evaporation under MDI and LESA; (2) assess soil water redistribution under MDI; (3) compare end-of-season profile soil water under MDI and LESA at two irrigation capacities 3.1 and 6.2 mm/day and to investigate design objectives that were implemented to overcome problems of earlier MDI designs. The experiments were conducted in western Kansas. Soil water evaporation was 35% lower under MDI. There was adequate redistribution of soil water in the subsurface. End-of-season soil water was significantly higher (p = 0.001) under MDI compared to LESA at the 3.1 mm/day irrigation capacity. Statistical uniformity of MDI was good ranging between 85 and 90%. The MDI system prevented deep wheel tracks and its redesign eliminated emitter clogging and reduced the frequency of the drip lines moving into the crop. The ability to better manage MDI due to design changes and its demonstration of superior performance in reducing soil water evaporation under limited canopy cover suggests that the system has the potential to enhance crop water productivity in a water-limited environment.