Soil Water Tension, a Powerful Tool for Productivity and Stewardship

A fundamental way to schedule irrigation is through the monitoring and management of soil water tension (SWT).  Soil water tension is the force necessary for plant roots to extract water from the soil.  With the invention of tensiometers, SWT measurements have been used to schedule irrigation.  There are seven different types of field instruments used to measure SWT, either directly or indirectly.  Automation of precision irrigation by SWT is a powerful tool to determine optimal irrigation criteria for plant performance.  Specific SWT criteria for irrigation scheduling have been developed to optimize the production and quality of vegetable crops, field crops, trees, shrubs, nursery crops, and for the management of landscape plants.  The known SWT criteria for irrigation scheduling will be reviewed.  By utilizing the ideal SWT and adjusting irrigation duration and amount, it is possible to simultaneously achieve production and environmental stewardship goals.