English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

. Measurements of the isotopic composition of separate andpotentially interacting pools of soil water provide a powerful means toprecisely resolve plant water sources and quantify water residence time andconnectivity among soil water regions during recharge events. Here wepresent an approach for quantifying the time-dependent isotopic mixing ofwater recovered at separate suction pressures or tensions in soil over anentire moisture release curve. We wetted oven-dried, homogenized sandy loamsoil first with isotopically “light” water (δ2H =-130 ‰; δ18O =-17.6 ‰) to represent antecedent moisture held at high matric tension. We thenbrought the soil to near saturation with “heavy” water (δ2H =-44 ‰; δ18O =-7.8 ‰) that represented new input water. Soil water sampleswere subsequently sequentially extracted at three tensions (“low-tension”centrifugation ≈0.016 MPa; “mid-tension” centrifugation ≈1.14 MPa; and “high-tension” cryogenic vacuum distillation at anestimated tension greater than 100 MPa) after variableequilibration periods of 0 h, 8 h, 1 d, 3 d, and 7 d. We assessed the differencesin the isotopic composition of extracted water over the 7 d equilibrationperiod with a MANOVA and a model quantifying the time-dependent isotopic mixingof water towards equilibrium via self-diffusion. The simplified andhomogenous soil structure and nearly saturated moisture conditions used inour experiment likely facilitated rapid isotope mixing and equilibrationamong antecedent and new input water. Despite this, the isotope compositionof waters extracted at mid compared with high tension remained significantlydifferent for up to 1 d, and waters extracted at low compared withhigh tension remained significantly different for longer than 3 d.Complete mixing (assuming no fractionation) for the pool of water extractedat high tension occurred after approximately 4.33 d. Our combinationapproach involving the extraction of water over different domains of themoisture release curve will be useful for assessing how soil texture andother physical and chemical properties influence isotope exchange and mixingtimes for studies aiming to properly characterize and interpret the isotopiccomposition of extracted soil and plant waters, especially under variablyunsaturated conditions.

A combination of soil water extraction methods quantifies the isotopic mixing of waters held at separate tensions in soil