Experiment Information Sign-ups Variable Rate Irrigation Experiment
Variable Rate Irrigation (VRI)
Variable rate irrigation is a different concept of irrigation system design and operation that is gaining interest in the Central Valley of California. It involves: 1) mapping a field or orchard to understand the type and extent of variable soil and its potential affect on crop production; 2) site-specific soil sampling and analysis to identify soil zones with significantly different water holding and distribution properties and soil fertility and/or salinity characteristics; 3) Designing and installing an irrigation system in zones that accounts for the natural patterns of variable soils and improves capacity and flexibility to irrigate as dictated by the different soils; and 4) crop and soil monitoring in each irrigation zone to optimize the application of water, fertilizers, and production in each zone and for the entire field or orchard.
The VRI concept utilizes the same drip emitter or microsprinkler (product) and the same drip or microsprinkler emitter spacing throughout the field or orchard so that maintenance needs for the system are consistent throughout the orchard. The VRI concept relies upon a single valve to control when and how much water or fertilizer is applied to each irrigation zone in the field or orchard. The VRI concept also uses variable frequency drives to manage the power requirement needed to pump different flow rates of water into different irrigation zones with different acreage.
VRI Field Trial Planned to Begin in 2013
An 80 acre field trial that will explore the merits of a Variable Rate Irrigation system is planned to be in place for the 2013 irrigation season. It will be located on the westside of Tehama County among some of the more commonly planted orchard soils (Tehama, Arbuckle, and other soil series). It will be planted to almonds and utilize a common minisprinkler. The trial will be designed to allow replicated, side-by-side comparisons of almonds irrigated with a traditionally designed system where the irrigation sets cross soil types and with VRI where the irrigation sets conform to the variable soils.
Invitation to Learn from this Field Trial
Groundbreaking for this multi-year trial has not yet been initiated but is expected to commence later this summer and fall. This trial will provide opportunities along the way to learn more about VRI. Topics will include: methods of mapping soil variability; evaluation of soil variability to identify irrigation zones; experiences and costs of designing and installing a VRI system, experiences with operating and managing VRI, and water, nutrient, and energy use and crop responses with VRI.
If you are interested in the opportunity to follow along with this experiment, visit the site and become involved in the progress of the project, go to the link below to sign up for future details and information.
Variable Rate Irrigation Experiment