Search results for "soil"
showing 10 items of 3493 documents
Investigation of surface properties of lunar regolith: Part I
2007
This paper describes an initial investigation of the surface properties of three lunar soil samples from the Apollo 11, 12 and 16 missions, respectively. We report on density measurements using a helium pycnometer, adsorption isotherms of krypton applied for the determination of specific surface area of the samples and gravimetric measurement of the isotherms of water, heptane and octane. Electron-microscopic photographs are described and discussed.
Herbicidal activity of Mediterranean essential oils and their effects on soil bioindicators.
2020
[ES] Las preocupaciones ambientales y de salud han estimulado el interés en estrategias alternativas para el manejo de las malas hierbas. En todo el mundo se están haciendo esfuerzos para reducir la gran dependencia de los herbicidas sintéticos que se utilizan como principal método para el control de las plantas arvenses. Los herbicidas naturales basados en sustancias alelopáticas, como los aceites esenciales (AEs) extraídos de plantas, se han sugerido como una de las posibles alternativas para lograr un manejo sostenible de las arvenses. Por un lado, los AEs han mostrado capacidad para inhibir la germinación y el crecimiento de semillas de malas hierbas, por otro lado, hay una falta de est…
Dicrocoelium dendriticum found in a Bronze Age cemetery in western Iran in the pre-Persepolis period: The oldest Asian palaeofinding in the present h…
2015
Dicrocoeliasis of animals and humans is caused by trematode species of the genus Dicrocoelium, mainly Dicrocoelium dendriticum in ruminants of the Holarctic region. D. dendriticum may be considered an old parasite, probably related to the appearance and diversification of Eurasian ovicaprines, occurred 14.7-14.5 million years ago. The oldest palaeoparasitological findings of Dicrocoelium in domestic animals and humans date from more than 5000 years BC in Europe. Eggs of D. dendriticum have been found in a burial of a Bronze Age cemetery (2600-2200 BC) close to Yasuj city, southwestern Iran. This is the oldest finding of D. dendriticum in the Near East, where present human infection reports …
Belowground responses by AM fungi and animal trophic groups to repeated defoliation in an experimental grassland community
2005
Abstract We tested a hypothesis that the effects of defoliation on plants and soil organisms vary with the number of successive defoliations. We established a 23-week greenhouse experiment using replicated grassland microcosms that were composed of three plant species, Trifolium repens , Plantago lanceolata and Phleum pratense , growing together in grassland soil with a diverse soil community. The experiment consisted of two treatment factors-defoliation and harvest time-in a fully factorial design. The defoliation treatment had two levels, i.e. no trimming and trimming of plants every 2 weeks, and the harvest time five levels, i.e. harvests after 1–3, 5 and 7 trimmings. Shoot production (t…
Beerkan Estimation of Soil Transfer parameters (BEST) across soils and scales
2019
Abstract Theories and models used in soil hydrological sciences rely on the knowledge of the spatially and temporally variable soil hydraulic properties, i.e. the water retention and hydraulic conductivity curves. Obtaining reliable experimental information on these curves for an area of interest is not easy and it still remains a challenge for soil scientists. In 2006, a simple and physically based methodology was proposed to completely characterize the soil using a single ring infiltration experiment in the field and determination of soil particle size distribution, initial and final soil water content and dry soil bulk density. This methodology, named BEST – Beerkan Estimation of Soil Tr…
Hexanoic acid is a resistance inducer that protects tomato plants againstPseudomonas syringaeby priming the jasmonic acid and salicylic acid pathways
2012
Summary Hexanoic acid-induced resistance (Hx-IR) is effective against several pathogens in tomato plants. Our study of the mechanisms implicated in Hx-IR against Pseudomonas syringae pv. tomato DC3000 suggests that hexanoic acid (Hx) treatment counteracts the negative effect of coronatine (COR) and jasmonyl-isoleucine (JA-Ile) on the salicylic acid (SA) pathway. In Hx-treated plants, an increase in the expression of jasmonic acid carboxyl methyltransferase (JMT) and the SA marker genes PR1 and PR5 indicates a boost in this signalling pathway at the expense of a decrease in JA-Ile. Moreover, Hx treatment potentiates 12-oxo-phytodienoic acid accumulation, which suggests that this molecule mig…
Evaluation of activated sludge model no.2 at high phosphorus concentrations
2001
This paper presents laboratory scale experimentation carried out to study enhanced biological phosphorus removal at high phosphorus concentrations in a sequencing batch reactor. Four series of data obtained in a sequencing batch reactor are examined in light of the Activated Sludge Model No. 2. This model was calibrated using data from the first and second series working at low phosphorus concentrations. The Activated Sludge Model No. 2 successfully characterised the enhanced biological phosphorus removal performance of the sequencing batch reactor at low phosphorus concentrations. The calibrated model was then used to adjust experimental results of the other series working at high phosphor…
A review of runoff generation and soil erosion across scales in semiarid south-eastern Spain
2011
Climate, lithology, soil and especially, intense land use/cover changes, make SE Spain very vulnerable to runoff generation and water erosion leading to loss of nutrients and organic matter and to infrequent but devastating floods, reservoir siltation and mass failures. This susceptibility has led to heavy economic investment and research efforts since the 1980s, making this region a worldwide reference for understanding the hydrology and geomorphology of semiarid ecosystems. Runoff and soil erosion have been intensively studied throughout the last decades in various natural ecosystems as well as in abandoned farmlands. Research has considered a wide range of methods and spatial and tempora…
Monitoring soil volume wetness in heterogeneous soils by electrical resistivity. A field-based pedotransfer function.: A field-based pedotransfer fun…
2014
11 pages; International audience; Modern irrigation techniques require accurate, rapid, cost-effective, spatial measurement of soil moisture. Electrical Resistivity Tomography (ERT) meets most of these requirements, but needs to be calibrated for each use because it is very sensitive to differences in soil characteristics. In this study, a pedotransfer function approach is used to remove the need for site-specific calibration, allowing ERT to be used directly to measure soil moisture. The study site was a hillslope vineyard, where eight calcaric-cambisol soil profiles were identified. From 2012 to 2013, 23 000 soil volume wetness measurements were acquired by Time Domain Reflectometry, and …
Proposal for a new diagnostic horizon for WRB Anthrosols
2009
Abstract To investigate man's role in the creation and evolution of soils in areas of large scale farming, and to investigate the main morpho-descriptive aspects of the related soils, a survey was carried out in south eastern Sicily, Italy, where, as common to other regions of the Mediterranean basin, there are wide areas with anthropogenic soils due to large scale farming activity. The complex genesis pattern of these anthropogenic soils, which shows a double sequence of man-made horizons, sideways oriented to the soil surface, does not allow their classification as Technosols, because their composition is not dominated or strongly influenced by artefacts or human-made materials as is the …