Global Change Abstracts The Swiss Contribution - SCNAT

Global Change Abstracts – The Swiss Contribution | Soil and Lithosphere 117
08.1-208
Bioavailability of pollutants and soil remediation
Ortega Calvo J J, Ball W P, Schulin R, Semple K T,
Wick L Y
Spain, USA, Switzerland, England, Germany
Agriculture, Soil Sciences , Toxicology
Journal of Environmental Quality, 2007, V36, N5,
SEP-OCT, pp 1383-1384.
08.1-209
New method for in situ characterization of
loose material for landslide mapping purpose
Pantet A, Parriaux A, Thelin P
Switzerland
Geomorphology , Geology , Instruments & Instrumentation
The assessment of grain size distribution and
plasticity of loose geological material, during in
situ geological investigations, is not obvious. Visual
appreciation allows an approximative quantification
of the coarse granulometric fractions,
but not of the fine ones. Field soils determination
methods suggested until now, are visual and tactile
tests leading to a very rough estimate, which
is only qualitative and not very reproducible. The
new proposed field test (GEOLEP method) allows a
quick quantification of the fine fraction of loose
material. It allows the determination of the sand
fraction (fine and medium grained sands) as well
as the methylene blue value of the samples. The
necessary equipment to perform this test is light
and compact and the time needed to analyze one
sample is approximately 15 min. Thus it is also
possible to carry out numerous measurements in
one day. The calibrations were carried out on a selection
of 13 natural samples, chosen for their representativeness
of the typical alpine quaternary
deposits. The results obtained with GEOLEP method
are relevant compared with standardized laboratory
tests; the obtained correlation indexes are
of 73% for the comparison with laboratory stain
test results and of 89% with a laboratory method
using a similar procedure than the field test. The
correlation we performed with Atterberg’s limits
tests shows that a rough approximation of plasticity
index can also be obtained (R-2 = 75%). This
method thus brings a new tool which should allow
taking into account the lithological factor (by
some quantitative and representative variables) in
a reliable way for the evaluation of landslide hazards.
(C) 2007 Elsevier B.V. All rights reserved.
Engineering Geology, 2007, V94, N3-4, NOV 2, pp
166-179.
08.1-210
Poplar for the phytomanagement of boron
contaminated sites
Robinson B H, Green S R, Chancerel B, Mills T M,
Clothier B E
Switzerland, New Zealand
Toxicology , Agriculture, Soil Sciences , Plant Sciences
Boron (B) is a widespread environmental contaminant
that is mobile relative to other trace
elements. We investigated the potential of hybrid
poplar (Populus sp.) for B phytomanagement using
a lysimeter experiment and a field trial on
B-contaminated wood-waste. In both studies, poplars
enhanced evapotranspiration from the woodwaste,
reduced B leaching, and accumulated Bin
the aerial portions of the tree. When grown in
a substrate containing 30 mg/kg B, poplar leaves
had an average B concentration of 845 mg/kg,
while the stems contained 21 mg/kg B. Leaf B
concentrations increased linearly with leaf age. A
decomposition experiment revealed that abscised
leaves released 14% of their B during the winter
months. Fertiliser application enhanced tree
growth without decreasing the leaf B concentrations.
Harvesting alternate rows of trees on a contaminated
site would reduce leaching from the
site while removing B. Harvested plant material
may provide bioenergy, stock fodder, or an amendment
for B-deficient soils.
Environmental Pollution, 2007, V150, N2, NOV, pp
225-233.
08.1-211
Changes in the macro-pore structure of
restored soil caused by compaction beneath
heavy agricultural machinery: a morphometric
study
Schäffer B, Stauber M, Müller R, Schulin R
Switzerland
Agriculture, Soil Sciences
Compaction can seriously degrade soil in modern
agriculture. Soil that has been temporarily removed
and stored is particularly sensitive to compaction
when restored, although little is known
about the structural changes in such soils under
mechanical loads. We investigated the structural
changes in a restored soil that had been gently cultivated
for several years and then was trafficked
by a heavy combine harvester, analysing the macro-pore
structure by quantitative morphometry of
three-dimensional microcomputed tomography
images. Increased trafficking caused decreases in
both the porosity and connectivity of the macropores.
The fraction of spherical pores (and thus the
convexity of the pore space) and the mean pore