Author
 |
Howell, Terry |
|
Submitted to: Encyclopedia of Soils in the Environment
Publication Type: Book / Chapter Publication Acceptance Date: 3/5/2004 Publication Date: 10/15/2004 Citation: Howell, T.A. 2004. Lysimetry. In: Hillel, D., editor. Encyclopedia of Soils in the Environment. Oxford, UK: Elsevier Press. p. 379-386. Interpretive Summary: Technical Abstract: Lysimeters are measurement devices used in soil physics, hydrologic, irrigation water requirement, and water quality research to measure the soil water balance and to separately determine the vertical water fluxes and/or soil water solute chemical transport. Primarily, they are used to determine the water consumed in evaporation and transpiration called evapotranspiration (ET). The two main types of lysimeters -- percolation and weighing -- are described and discussed. Percolation lysimeters usually have less precision in measuring ET. Weighing lysimeters directly measure the water consumed through ET processes. Both types can permit accurate drainage measurements and collect water samples that can be chemically analyzed. Several important lysimeter design considerations like shape, depth, monolith collection, and drainage system were discussed. Measurement of ET was highlighted and described in detail giving an example of ET for alfalfa at Bushland, TX, on two days in 1998 with differing environments greatly affecting crop ET. |
