Details
| Original language | English |
|---|---|
| Pages (from-to) | 601-605 |
| Number of pages | 5 |
| Journal | Soil Science Society of America Journal |
| Volume | 82 |
| Issue number | 3 |
| Publication status | Published - 19 Apr 2018 |
Abstract
Peat soils shrink and become very hydrophobic when dried. Both properties may cause inaccuracies when applying laboratory methods for soil hydraulic properties that have been developed and tested for mineral soils. This study aimed to compare different methods for the determination of the water retention of peat soils near permanent wilting point (pF 3.5 to 4.2). Three common methods were tested: two pressure apparatus (ceramic plate [Soilmoisture] vs. membrane [eijkelkamp]) and a dew-point potentiameter (WP4C, Decagon Devices, Inc.), which is based on the equilibrium of soil water potential with air humidity. We used both field-moist peat samples and samples that had been rewetted after oven-drying. We found that there was no systematic difference between the two pressure apparatus. Low moisture variability among replicates and dew-point potentiameter measurements that indicated a drainage to pF 4.2 support the use of pressure apparatus for the determination of water retention near permanent wilting point. Despite a rewetting time of 2 wk including periodic mixing, rewetted oven-dried samples showed lower soil moistures at pF 3.5 and 4.2 than field-moist ones. This severe and long-lasting hysteresis effect was strongest for less decomposed peat samples. Thus, field-moist samples should be used. This makes the classical dew-point potentiameter measurement protocol, which is based on defined water additions to oven-dried samples, unsuitable for peat samples.
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)
- Soil Science
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In: Soil Science Society of America Journal, Vol. 82, No. 3, 19.04.2018, p. 601-605.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Comparing Methods for Measuring Water Retention of Peat Near Permanent Wilting Point
AU - Bechtold, Michel
AU - Dettmann, Ullrich
AU - Wöhl, Lena
AU - Durner, Wolfgang
AU - Piayda, Arndt
AU - Tiemeyer, Bärbel
N1 - Funding information: The samples were provided by the FACCE-JPI ERA-NET Plus on Climate Smart Agriculture project “CAOS” which is funded by the German Federal Ministry of Education and Research (BMBF) under grant No. 031A543A. M. Bechtold thanks the Alexander von Humboldt Foundation for a Feodor Lynen Fellowship.
PY - 2018/4/19
Y1 - 2018/4/19
N2 - Peat soils shrink and become very hydrophobic when dried. Both properties may cause inaccuracies when applying laboratory methods for soil hydraulic properties that have been developed and tested for mineral soils. This study aimed to compare different methods for the determination of the water retention of peat soils near permanent wilting point (pF 3.5 to 4.2). Three common methods were tested: two pressure apparatus (ceramic plate [Soilmoisture] vs. membrane [eijkelkamp]) and a dew-point potentiameter (WP4C, Decagon Devices, Inc.), which is based on the equilibrium of soil water potential with air humidity. We used both field-moist peat samples and samples that had been rewetted after oven-drying. We found that there was no systematic difference between the two pressure apparatus. Low moisture variability among replicates and dew-point potentiameter measurements that indicated a drainage to pF 4.2 support the use of pressure apparatus for the determination of water retention near permanent wilting point. Despite a rewetting time of 2 wk including periodic mixing, rewetted oven-dried samples showed lower soil moistures at pF 3.5 and 4.2 than field-moist ones. This severe and long-lasting hysteresis effect was strongest for less decomposed peat samples. Thus, field-moist samples should be used. This makes the classical dew-point potentiameter measurement protocol, which is based on defined water additions to oven-dried samples, unsuitable for peat samples.
AB - Peat soils shrink and become very hydrophobic when dried. Both properties may cause inaccuracies when applying laboratory methods for soil hydraulic properties that have been developed and tested for mineral soils. This study aimed to compare different methods for the determination of the water retention of peat soils near permanent wilting point (pF 3.5 to 4.2). Three common methods were tested: two pressure apparatus (ceramic plate [Soilmoisture] vs. membrane [eijkelkamp]) and a dew-point potentiameter (WP4C, Decagon Devices, Inc.), which is based on the equilibrium of soil water potential with air humidity. We used both field-moist peat samples and samples that had been rewetted after oven-drying. We found that there was no systematic difference between the two pressure apparatus. Low moisture variability among replicates and dew-point potentiameter measurements that indicated a drainage to pF 4.2 support the use of pressure apparatus for the determination of water retention near permanent wilting point. Despite a rewetting time of 2 wk including periodic mixing, rewetted oven-dried samples showed lower soil moistures at pF 3.5 and 4.2 than field-moist ones. This severe and long-lasting hysteresis effect was strongest for less decomposed peat samples. Thus, field-moist samples should be used. This makes the classical dew-point potentiameter measurement protocol, which is based on defined water additions to oven-dried samples, unsuitable for peat samples.
UR - http://www.scopus.com/inward/record.url?scp=85047120571&partnerID=8YFLogxK
U2 - 10.2136/sssaj2017.10.0372
DO - 10.2136/sssaj2017.10.0372
M3 - Article
AN - SCOPUS:85047120571
VL - 82
SP - 601
EP - 605
JO - Soil Science Society of America Journal
JF - Soil Science Society of America Journal
SN - 0361-5995
IS - 3
ER -