Search results for "soil water"
showing 10 items of 840 documents
Discrimination of Lithogenic and Anthropogenic Metals in Calcareous Agricultural Soils: A Case Study of the Lower Vinalopó Region (SE Spain)
2008
Analysis of heavy metal concentrations in soils and their sources is required to identify agricultural areas affected by contamination on a regional level, according to the European Thematic Strategy for Soil Protection. Pseudo-total and EDTA-extractable concentrations of nine elements (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) in eighteen agricultural soils with vegetable crops in the Lower Vinalopo region (southeast Spain) were determined. The main aim was to assess the present state of the agricultural soils in relation to contamination processes by heavy metals for a representative area of the Mediterranean region under semiarid conditions. The pseudo-total concentrations for heavy metals …
Soil aggregate stability under different Mediterranean vegetation types
1998
The influence of vegetation type on soil erodibility was studied by means of aggregate stability measurements using the Modified Emerson Water Dispersion Test (MEWDT), water-drop impacts (CND and TDI) and Ultrasonic Disruption (UD) methods on soils from north-facing slopes of the mountain range of La Serra Grossa in the eastern Iberian Peninsula. Soils with similar characteristics but covered by the main plant species at the study area were selected. Quercus ilex woodland showed the most resistant soil aggregates followed by Q. coccifera and Pistacea lentiscus scrubland, Brachypodium retusum grassland and Pinus halepensis woodland. Aggregates developed beneath dwarf shrubs like Rosmarinus o…
Four-year soil erosion rates in a running-mountain trail in eastern Iberian Peninsula
2019
During the last decades, the use of mountain trails for running is more and more popular. New trails are opened to allow the runners to practice and compete. This form of human impact on the landscape is new as the new trails do not follow the conservation strategies in design and maintenance as traditional mountain trails constructed by farmers, shepherds and muleteers do. This impact of sport events in nature is not measured and we know little about this impact on vegetation, fauna and soils. We surveyed in September 2018 a trail that was opened in September 2014 and was used for four official mountain trail races, and for training by local runners. Our interviews with organizers and user…
Comparing different methods to determine soil physical quality in a mediterranean forest and pasture land
2016
Soil physical quality (SPQ) can be assessed by different experimental methodologies and criteria and the optimal/critical values or ranges for SPQ indicators are still approximate. Sampling soils with minimal anthropic pressures should allow improvements in SPQ assessment. Different experimental methodologies and criteria were applied to sample a Mediterranean oak forest (Quercus ilex L.) and pasture land, in Sicily, with a varying degree of anthropic disturbance. Soil water retention was determined in the laboratory and the field, using the BEST (Beerkan Estimation of Soil Transfer parameters) procedure of soil hydraulic characterization. Capacity-based indicators, the S index, and locatio…
Application of minidisk infiltrometer to estimate water repellency in Mediterranean pine forest soils
2017
Assessment of soil water repellency (SWR) was conducted in the decomposed organic floor layer (duff) and in the mineral soil layer of two Mediterranean pine forests, one in Italy and the other in Spain, by the widely-used water drop penetration time (WDPT) test and alternative indices derived from infiltration experiments carried out by the minidisk infiltrometer (MDI). In particular, the repellency index (RI) was calculated as the adjusted ratio between ethanol and water soil sorptivities whereas the water repellency cessation time (WRCT) and the specifically proposed modified repellency index (RIm) were derived from the hydrophobic and wettable stages of a single water infiltration experi…
An integrated view of the chemistry and mineralogy of martian soils
2005
The mineralogical and elemental compositions of the martian soil are indicators of chemical and physical weathering processes. Using data from the Mars Exploration Rovers, we show that bright dust deposits on opposite sides of the planet are part of a global unit and not dominated by the composition of local rocks. Dark soil deposits at both sites have similar basaltic mineralogies, and could reflect either a global component or the general similarity in the compositions of the rocks from which they were derived. Increased levels of bromine are consistent with mobilization of soluble salts by thin films of liquid water, but the presence of olivine in analysed soil samples indicates that the…
Modeling the mobility of glyphosate from two contrasting agricultural soils in laboratory column experiments
2019
Glyphosate (GLP) currently is one of the most widely used herbicides worldwide. The persistence of GLP and its major metabolite, aminomethylphosphonic acid (AMPA) in the environment has been described by other authors. This study was aimed at comparing the GLP and AMPA behavior in sandy and loamy sand soils after spiking with enhanced (445 µg g−1) concentrations of GLP in herbicide KLINIK® (Nufarm, Austria) and bioaugmentation followed by 40 days weathering and a consistent three-stage leaching in a laboratory column experiment. Soil samples were obtained from mineral topsoil (0–10 cm) within former agricultural lands where soil parent material was formed by glacigenic deposits. The total a…
Soil water content assessment: Seasonal effects on the triangle method
2016
Among indirect estimations of the soil water content in the upper layer, the "triangle method" is based on the relationship between the optical and thermal features sensed via Earth Observation. These features are controlled by water content at surface and within root zone, but also by meteorological forcing including air temperature and humidity, and solar radiation. Night and day-time MODIS composite land-surface temperature (LST) allowed applying the thermal admittance version of the method; by taking into account the temporal admittance of the soil, this version was previously found achieving high accuracy in estimate the soil water content at high spatial resolution within a short time…
Methanotrophic activity and diversity of methanotrophs in volcanic geothermal soils at Pantelleria (Italy)
2014
Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas twenty-five times as potent as CO2. Recently, it has been demonstrated that volcanic or geothermal soils are not only a source of methane, but are also sites of methanotrophic activity. Methanotrophs are able to consume 10–40 Tg of CH4 a−1 and to trap more than 50% of the methane degassing through the soils. We report on methane microbial oxidation in the geothermally most active site of Pantelleria (Italy), Favara Grande, whose total methane emission was previously estimated at about 2.5 Mg a−1 (t a−1). Laboratory incubation experiments with three top-soil samples from …
Group-specific quantification of methanotrophs in landfill gas-purged laboratory biofilters by tyramide signal amplification-fluorescence in situ hyb…
2008
The aim of this study was to quantitatively analyse methanotrophs in two laboratory landfill biofilters at different biofilter depths and at temperatures which mimicked the boreal climatic conditions. Both biofilters were dominated by type I methanotrophs. The biofilter depth profiles showed that type I methanotrophs occurred in the upper layer, where relatively high O(2) and low CH(4) concentrations were present, whereas type II methanotrophs were mostly distributed in the zone with high CH(4) and low O(2) concentrations. The number of type I methanotrophic cells declined when the temperature was raised from 15 degrees C to 23 degrees C, but increased when lowered to 5 degrees C. A slight …