Permanent wilting point
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Permanent wilting point (PWP) or wilting point (WP) is defined as the minimum amount of water in the soil that the plant requires not to
turgidity when placed in a saturated atmosphere for 12 hours. The physical definition of the wilting point, symbolically expressed as θpwp or θwp, is said by convention as the water content at −1,500 kPa (−15 bar) of suction pressure, or negative hydraulic head.[1]
History
The concept was introduced in the early 1910s.
Lyman Briggs and Homer LeRoy Shantz (1912) proposed the wilting coefficient, which is defined as the percentage water content of a soil when the plants growing in that soil are first reduced to a wilted condition from which they cannot recover in approximately saturated atmosphere without the addition of water to the soil.[2][3] See pedotransfer function
for wilting coefficient by Briggs.
Frank Veihmeyer and Arthur Hendrickson from University of California-Davis found that it is a constant (characteristic) of the soil and is independent of environmental conditions. Lorenzo A. Richards proposed it is taken as the soil water content when the soil is under a pressure of −15 bar.[4]
See also
- Available water capacity
- Ecohydrology
- Field capacity
- Moisture equivalent
- Moisture stress
- Nonlimiting water range
- Soil plant atmosphere continuum
- Water retention curve