Soil water potential
nounPronunciation: /sɔɪl ˈwɔːtə pəˈtenʃəl/
The thermodynamic potential of water in soil that drives water movement and plant water availability, determined by matric, osmotic, and gravitational components. This parameter directly controls plant water uptake and is essential for predicting plant stress responses.
Plain English
A measure of how tightly water is held in soil, determining how easily plants can access and absorb water.
Etymology & History
Usage
"Soil water potential declined below -1.5 MPa during the drought period, preventing water uptake by wheat roots."
Style guide notes: Always specify measurement method and soil depth when reporting soil water potential values.
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Related Terms
Frequently Asked Questions
What units measure soil water potential?
Soil water potential is expressed in megapascals (MPa) or kilopascals (kPa), with negative values indicating water stress.
How does soil water potential affect plant growth?
Lower soil water potential restricts plant water uptake, reducing cell turgor, photosynthesis, and growth until wilting occurs.
Why Test Candidates on This?
Soil water potential is critical for understanding drought stress mechanisms and predicting plant responses to water limitation.
Required skill level: Senior