 |
| Titel |
Effect of freeze-thawing on aggregate stability in a calcareous Mediterranean soil |
| VerfasserIn |
Elena Lozano, Beatriz Temporal, Ángel Oltra, Jorge Mataix-Solera, Victoria Arcenegui, Fuensanta Garcia-Orenes |
| Konferenz |
EGU General Assembly 2013
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250072908
|
|
|
|
|
|
| Zusammenfassung |
| Soil freezing has been reported as both beneficial and detrimental for soil structure depending
on various factors (Dagesse, 2011), but the subsequent thawing process has not been
adequately investigated as a factor in determining the net effect of freezing and
thawing.
In this study changes in soil aggregate stability (AS) were studied under different
moisture and speed of thawing conditions in a laboratory experiment. Conditions favoring
sublimation and commonly experienced during the winter include bare soil surfaces and
synoptic meteorological conditions of clear skies, low humidity, and moderate winds.
Aggregate stability measured may therefore reflect the effects of drying of the soil
aggregates via the freezing process and the resulting water content distribution following
thawing. The soil used is from an agricultural area located in Sierra de Enguera
(Valencia, E Spain). Soil samples were collected in February 2012 from the first 2.5
cm depth of A horizon. We also studied the effect of a mulch cover in buffering
soil temperature during 2 months under field conditions using thermocouples and
data-loggers.
Soil samples at two initial water contents (10% and 40%) were subjected to different
treatments, including not frozen (control), freeze-thaw (freezing at -4 ºC for 3 h and thawing
at room temperature for 24 h) and freeze-drying (freezing at -4 for 3h and thawing at 60 ºC
for 3 h in a forced air oven). We measured the possible soil disruption of soil aggregates
quantifying the soil mass in the fractions 2-0.25 mm and |
|
|
|
|
|
|