Diel plant water use and competitive soil cation exchange interact to enhance NH4+ and K+ availability in the rhizosphere
Espeleta, Javier F.
Cardon, Zoe G.
Mayer, K. Ulrich
Neumann, Rebecca B.
MetadataShow full item record
KeywordHydraulic redistribution; Nighttime transpiration; Plant nutrient uptake; Reactive-transport; Rhizosphere; Root water uptake
Hydro-biogeochemical processes in the rhizosphere regulate nutrient and water availability, and thus ecosystem productivity. We hypothesized that two such processes often neglected in rhizosphere models — diel plant water use and competitive cation exchange — could interact to enhance availability of K+ and NH4+, both high-demand nutrients. A rhizosphere model with competitive cation exchange was used to investigate how diel plant water use (i.e., daytime transpiration coupled with no nighttime water use, with nighttime root water release, and with nighttime transpiration) affects competitive ion interactions and availability of K+ and NH4+. Competitive cation exchange enabled low-demand cations that accumulate against roots (Ca2+, Mg2+, Na+) to desorb NH4+ and K+ from soil, generating non-monotonic dissolved concentration profiles (i.e. ‘hotspots’ 0.1–1 cm from the root). Cation accumulation and competitive desorption increased with net root water uptake. Daytime transpiration rate controlled diel variation in NH4+ and K+ aqueous mass, nighttime water use controlled spatial locations of ‘hotspots’, and day-to-night differences in water use controlled diel differences in ‘hotspot’ concentrations. Diel plant water use and competitive cation exchange enhanced NH4+ and K+ availability and influenced rhizosphere concentration dynamics. Demonstrated responses have implications for understanding rhizosphere nutrient cycling and plant nutrient uptake.
© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Plant and Soil 414 (2017): 33-51, doi:10.1007/s11104-016-3089-5.
Suggested CitationPlant and Soil 414 (2017): 33-51
The following license files are associated with this item:
Showing items related by title, author, creator and subject.
Significant biologically mediated CO2 uptake in the pacific arctic during the late open water season. Juranek, Laurie W.; Takahashi, Taro; Mathis, Jeremy T.; Pickart, Robert S. (American Geophysical Union, 2019-01-10)Shifting baselines in the Arctic atmosphere‐sea ice‐ocean system have significant potential to alter biogeochemical cycling and ecosystem dynamics. In particular, the impact of increased open water duration on lower trophic ...
The impact of the North Atlantic Oscillation on the uptake and accumulation of anthropogenic CO2 by North Atlantic Ocean mode waters Levine, Naomi M.; Doney, Scott C.; Lima, Ivan D.; Wanninkhof, Rik; Bates, Nicholas R.; Feely, Richard A. (American Geophysical Union, 2011-09-21)The North Atlantic Ocean accounts for about 25% of the global oceanic anthropogenic carbon sink. This basin experiences significant interannual variability primarily driven by the North Atlantic Oscillation (NAO). A suite ...
Salguero-Gomez, Roberto; Jones, Owen R.; Archer, C. Ruth; Buckley, Yvonne M.; Che-Castaldo, Judy; Caswell, Hal; Hodgson, David; Scheuerlein, Alexander; Conde, Dalia A.; Brinks, Erik; de Buhr, Hendrik; Farack, Claudia; Gottschalk, France; Hartmann, Alexander; Henning, Anne; Hoppe, Gabriel; Romer, Gesa; Runge, Jens; Ruoff, Tara; Wille, Julia; Zeh, Stefan; Davison, Raziel; Vieregg, Dirk; Baudisch, Annette; Altwegg, Res; Colchero, Fernando; Dong, Ming; de Kroon, Hans; Lebreton, Jean-Dominique; Metcalf, Charlotte J. E.; Neel, Maile M.; Parker, Ingrid M.; Takada, Takenori; Valverde, Teresa; Velez-Espino, Luis A.; Wardle, Glenda M.; Franco, Miguel; Vaupel, James W. (John Wiley & Sons, 2014-11-09)Schedules of survival, growth and reproduction are key life-history traits. Data on how these traits vary among species and populations are fundamental to our understanding of the ecological conditions that have shaped ...