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ARS Home » Midwest Area » Ames, Iowa » National Laboratory for Agriculture and The Environment » Agroecosystems Management Research » Research » Publications at this Location » Publication #389221
Research Project: Agroecosystem Benefits from the Development and Application of New Management Technologies in Agricultural Watersheds

Location: Agroecosystems Management Research

Title: Plant Available Water

Author
item DE JONG VAN LIER, QUIRJIN - Universidade De Sao Paulo
item Logsdon, Sally
item PINHEIRO, EVERTON - Federal University Of Mato Grosso
item GUBIANI, PAULO - Universidade Federal De Santa Maria

Submitted to: Encyclopedia of Soils in the Environment
Publication Type: Book / Chapter
Publication Acceptance Date: 3/8/2022
Publication Date: 5/1/2022
Citation: De Jong Van Lier, Q., Logsdon, S.D., Pinheiro, E.A., Gubiani, P.I. 2022. Plant Available Water. In: Hallett, P., editor. Encyclopedia of Soils in the Environment. 2nd edition. New York, NY: Elsevier. https://doi.org/10.1016/B978-0-12-822974-3.00043-4.
DOI: https://doi.org/10.1016/B978-0-12-822974-3.00043-4

Interpretive Summary: Knowing how much water is in the soil is important for managing crop growth and irrigation. Not all of the water in the soil can be used by plant, only the “plant available water.” While some water drains through the soil too fast to be used, some water is held tightly by soil and the plants cannot use it. This review summarizes the latest information on plant available water. This information is useful for scientists who advise crop and irrigation managers.

Technical Abstract: Soil water mediates important ecosystem services in the Critical Zone, but not all water in the soil can equally be used by plants. The maximum amount of water a soil can hold and made available to plants is important to agronomy, soil science, climatology, hydrology, and ecology. Plant available water is a static indicator of the maximum water storage capacity of a soils, but this does not convey the dynamics of water release from soil to plant roots. Field capacity is the upper limit of available water and is the water content after major drainage has ceased. Although usually determined by static cutoff values, field capacity varies depending on growing root system, flow of soil water to the root zone, and whether the soil can supply enough air to the roots. Permanent wilting point is the lower limit of total available water, but there may be a wetter limit to the lower end of readily available water. Plant available water is limited by soil compaction and not enough air in the soil. Proper management of the soil can increase plant available water.