Author
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Skinner, Robert |
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Submitted to: Agronomy Abstracts
Publication Type: Abstract Only Publication Acceptance Date: 7/28/2004 Publication Date: 10/31/2004 Citation: Skinner, R.H. 2004. Hydraulic lift in humid-temperate pasture systems[abstract]. Agronomy Abstracts. Paper No. 3667. Interpretive Summary: Technical Abstract: In arid ecosystems, deep-rooted species can facilitate the survival and growth of neighboring shallow-rooted species by transferring water from deep to shallow soil layers through a process known as hydraulic lift. This research investigated the occurrence of hydraulic lift in humid-temperate ecosystems where periodic drought occurs against a background of generally favorable soil moisture availability. Perennial ryegrass (Lolium perenne L.), orchardgrass (Dactylis glomerata L.) and white clover (Trifolium repens L.) were sown as grass/legume mixtures into field plots where rainfall could be excluded by moveable rainout shelters. Half the plots also included a deep-rooted perennial forb (chicory; Cichorium intybus L.). Rainfall was withheld from drought stressed plots for about 30 d during June and August in 2003 and 2004, and leaf elongation rate, leaf water potential, near surface soil temperature, soil water potential at a depth of 25 cm, and canopy light attenuation were measured. Diurnal changes in soil water potential were used to verify the occurrence of hydraulic lift. This presentation will discuss how the presence of chicory affected leaf growth and water relations for the grass and legume species. The effect of hydraulic lift on plant responses to drought will also be discussed. |
