Soil matric potential
noun phrasePronunciation: /sɔɪl ˈmeɪtrɪk pəˈtenʃəl/
The potential energy of water in soil measured relative to pure water, expressed in pressure units (kPa or MPa), which drives water availability to plant roots. This parameter integrates soil water content, texture, and pore structure to quantify water stress severity.
Plain English
A measurement of how tightly soil holds water, determining how easily plant roots can access it.
Etymology & History
Usage
"At soil matric potential below -1.5 MPa, most agricultural crops experience severe water stress and reduced productivity."
Style guide notes: Express values in MPa with negative sign; distinguish from plant water potential which includes osmotic and turgor components.
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Contrasted with
Related Terms
Frequently Asked Questions
How is soil matric potential measured in field conditions?
Tensiometers, psychrometers, and time-domain reflectometry probes are standard instruments for measuring soil matric potential.
What soil matric potential threshold triggers plant stress responses?
Most crops begin experiencing water stress around -0.1 to -0.3 MPa, with severe stress occurring below -1.5 MPa.
Why Test Candidates on This?
Critical for designing irrigation schedules, predicting drought stress onset, and managing abiotic stress in agriculture.
Required skill level: Mid