HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Free via Open Access Figures Only OA Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Google Scholar Articles by van der Ploeg, M. J. Articles by de Rooij, G. H. PubMed Articles by van der Ploeg, M. J. Articles by de Rooij, G. H. GeoRef GeoRef Citation Agricola Articles by van der Ploeg, M. J. Articles by de Rooij, G. H. Related Collections Soil Methods/Instrumentation Lysimeter/Rhizosphere Studies Plant and Environment Interactions

SPECIAL SECTION: ROOTS AND ROOT FUNCTION

Matric Potential Measurements by Polymer Tensiometers in Cropped Lysimeters under Water-Stressed Conditions

^a Wageningen Univ., Dep. of Environmental Science, Soil Physics, Ecohydrology and Groundwater Management Group, Droevendaalsesteeg 4, 6708 PB, Wageningen, The Netherlands
^b ALTERRA, Droevendaalsesteeg 4, 6708 PB, Wageningen, The Netherlands
^* Corresponding author (martine.vanderploeg{at}wur.nl).

Received 1 June 2007.

In many regions of the world, plant growth and productivity are limited by water deficits. As a result of more frequent and intense droughts, the area of land characterized as very dry has more than doubled since the 1970s. Consequently, understanding root water uptake under water-stressed conditions is gaining importance. The performance of a recently developed polymer tensiometer (POT) designed to measure matric potentials down to –1.6 MPa was evaluated and compared with volumetric moisture content measurements in dry soil. Three irrigation intensities created severe, intermediate, and no water stress conditions in lysimeters with growing maize (Zea mays L.) plants. By monitoring matric potentials using POTs, levels of local water stress in our experiments were better defined. When the defined stress levels were reached, volumetric moisture measurements for this particular loam soil were below 0.1, thus less informative compared with matric potential measurements. The observed matric potential profiles indicate significant root water uptake between 0.3- and 0.5-m depth in the later growth stages under water-stressed conditions. The temporal pattern of matric potential profiles reflected changing root water uptake behavior under dry conditions. As the total soil water potential is a direct indication of the amount of energy required by plants to take up water, POTs may contribute to quantifying root water uptake in dry soils.

Abbreviations: IS, intermediate stress • NS, no stress • POT, polymer tensiometer • RLD, root length density • SS, severe stress • TDR, time domain reflectometry

This article has been cited by other articles:

				T. H. Skaggs and P. J. Shouse Roots and Root Function: Introduction Vadose Zone J., August 1, 2008; 7(3): 1008 - 1009. [Full Text] [PDF]