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
wilt. If the soil water content decreases to this or any lower point a plant wilts and can no longer recover its
turgid
Turgor pressure is the force within the cell that pushes the plasma membrane against the cell wall.
It is also called ''hydrostatic pressure'', and is defined as the pressure in a fluid measured at a certain point within itself when at equilibriu ...
ity when placed in a saturated atmosphere for 12 hours. The physical definition of the wilting point, symbolically expressed as or , is said by convention as the
water content
Water content or moisture content is the quantity of water contained in a material, such as soil (called soil moisture), rock, ceramics, crops, or wood. Water content is used in a wide range of scientific and technical areas, and is expressed as ...
at of suction pressure, or negative
hydraulic head.
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''. See
pedotransfer function In soil science, pedotransfer functions (PTF) are predictive functions of certain soil properties using data from soil surveys.
The term ''pedotransfer function'' was coined by Johan Bouma as ''translating data we have into what we need''. The mo ...
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
Lorenzo Adolph Richards (April 24, 1904 – March 12, 1993) or known as ''Ren'' was one of the 20th century's most influential minds in the field of soil physics.
Biography Early life
Lorenzo A. Richards was born on April 24, 1904, in the town of ...
proposed it is taken as the soil water content when the soil is under a pressure of −15 bar.
[{{cite journal, author1=Veihmeyer, F.J. , author2=Hendrickson, A.H. , name-list-style=amp , year=1928, title=Soil moisture at permanent wilting of plants , journal=Plant Physiol. , volume=3 , pages=355–357, doi=10.1104/pp.3.3.355, pmid=16652577, issue=3, pmc=440017 ]
See also
*
Available water capacity
*
Ecohydrology
Ecohydrology (from Greek , ''oikos'', "house(hold)"; , ''hydōr'', "water"; and , '' -logia'') is an interdisciplinary scientific field studying the interactions between water and ecological systems. It is considered a sub discipline of hydrology, ...
*
Field capacity Field capacity is the amount of soil moisture or water content held in the soil after excess water has drained away and the rate of downward movement has decreased. This usually takes place 2–3 days after rain or irrigation in pervious soils of u ...
*
Moisture equivalent
*
Moisture stress
*
Nonlimiting water range The non-limiting water range (NLWR) represents the range of water content in the soil where limitations to plant growth (such as water potential, air-filled porosity, or soil strength) are minimal. John Letey (1985) from UC Riverside introduced the ...
*
Soil plant atmosphere continuum
The soil-plant-atmosphere continuum (SPAC) is the pathway for water moving from soil through plants to the atmosphere. Continuum in the description highlights the continuous nature of water connection through the pathway. The low water potential of ...
*
Water retention curve
Water retention curve is the relationship between the water content, θ, and the soil water potential, ψ. This curve is characteristic for different types of soil, and is also called the soil moisture characteristic.
It is used to predict the ...
References
Soil physics
Hydrology
Forest pathology