Whalley, W.R.; Clark, L.J.; Gowing, D.J.G.; Cope, R.E.; Lodge, R.J. and Leeds-Harrison, P.B.
|DOI (Digital Object Identifier) Link:||http://dx.doi.org/10.1007/s11104-005-3485-8|
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Shoot growth in wheat is sensitive to high soil strength, but as high strength and drying tend to occur together it has proved difficult to separate the effects of water stress and mechanical impedance. The results of two field experiments in 2003 and 2004, where soil strength was manipulated by compaction and irrigation, demonstrated that the yield of wheat (Triticum aestivum L.) was sensitive to physical stress in the root zone. We obtained linear relationships between yield and soil strength and between yield and accumulated soil moisture data (accumulation analogous to thermal time), with similar slopes for both seasons. We were unable to detect root-sourced signals of xylem-sap ABA concentration, despite changes in stomatal conductance. When mechanical impedance and matric potential were varied independently in controlled environments, the growth of wheat was sensitive to mechanical impedance, but not to small changes in matric potential. While the response of stomatal conductance to soil drying in the field could be interpreted as evidence of hydraulic signalling, we suggest that the role of high soil strength, in limiting growth rates on moderately dry soil, requires further research.
|Item Type:||Journal Article|
|Extra Information:||Some of the symbols may not have transferred correctly into this bibliographic record and/or abstract.|
|Keywords:||matric potential; penetrometer resistance; signalling; soil strength; stomatal conductance; wheat|
|Academic Unit/Department:||Science > Environment, Earth and Ecosystems|
|Interdisciplinary Research Centre:||OpenSpace Research Centre (OSRC)
Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)
|Depositing User:||David Gowing|
|Date Deposited:||05 Jul 2006|
|Last Modified:||21 Oct 2011 08:22|
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