Skip to main content

Water Programs

Water Programs

Water and Agriculture: Irrigation

Irrigation is used to provide water needed by plants that is not provided by rainfall. How irrigation is managed and the type of water used for irrigation varies throughout the state depending on the particular crop and resources available. A fundamental component of efficient irrigation is to determine the quantity of irrigation needed and when to apply it, or irrigation scheduling.

Reclaimed Water as an Irrigation Source

Traditionally, groundwater and surface water resources were used for irrigation. However, the demand on water supplies has led to a growing interest in reclaimed water sources.

EDIS Publications

.Microirrigation lines running through a crop row

Irrigation management

Irrigation systems may be managed using different approaches. In addition, irrigation systems may be modified to increase water use efficiency or to accommodate new production conditions.

EDIS Publications

Irrigation Scheduling

Irrigation scheduling refers to how the amount and timing of irrigation is determined. There are different ways to approach irrigation scheduling, including soil moisture sensor (SMS) based methods and evapotranspiration or weather based methods. Tensiometric methods may also be used.

I. SMS-based

SMS-based irrigation scheduling relies on using a sensor to estimate soil water content for making decisions on when to irrigate.

II. Weather/evapotranspiration (ET) data

Weather- or ET-based scheduling relies on weather data to create a water balance which estimates irrigation needs.


Smartphone apps have been developed to assist with determining irrigation schedules for different commodities.


Tensiometeric methods rely on using soil-water suction as a measurement of plant-available water.