The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Surface cracks develop in many clay soils as they dry. Since they are difficult to adequately sample in most volumetric samples, it is useful to measure them so that volumetric measurements of water content, for example, can be corrected. A method for measuring cracks in soils is described. A transect consisting of six linked semi-circles, each of 1 m diameter, is used to count intercepts with...
Although phosphorus is often assumed to be relatively immobile in soils, significant redistribution occurs during pedogenesis. We quantified P redistribution as a result of 13,000 yr of pedogenesis in soil profiles along an environmental gradient of increasing moisture availability and along toposequences in the Brown and Dark Brown Chernozemic, and Gray Luvisolic soil zones of Saskatchewan. Soil...
Quantitative statements about soil development on a landscape level of scale are difficult to work out, especially in soils of stratified sediments. This article presents an easily applicable method to infer gains and losses of Fe, Mn and P in soilscapes developed on sedimentary rocks. For this an element: clay-ratio was introduced: The amounts of pedogenic (= CBD) Fe, Mn and total P (in kg) were...
The particles moving in suspension through the soil can carry heavy metals with them. We have studied over two years the movement of Cu, Cd, Zn, Al, Fe, Ca, K, Mg, Na and Mn in this way with small open tension-free lysimeters installed in a Podzosol (French classification). Soil solutions were filtered through 0.45 μm membranes and analysed for the composition of the soluble fraction. The membranes...
Soil is a complex organo-mineral association capable of sustaining all the terrestrial ecosystems on earth. It is a fundamental part of the environment upon which human beings and most other life forms depend, but despite this, soil is a grossly undervalued component of the natural world. Concerned by the lack of impact soil science has had, a group of soil scientists at a meeting in Rennes, concluded...
Soils on Seward Peninsula, northwest Alaska, that were buried about 17,500 years ago and froze after burial present a unique opportunity to study soil development under the conditions of the last glacial maximum. Stratigraphic sections were excavated during the summers of 1993 and 1994. Study sites were located on steep banks of thaw lakes. We described soil morphology (including cryogenic features)...
Sixteen pedons developed in various parent materials in Kentucky were studied in order to quantify fragipan strength and expression. The contribution to soil strength by clay, bulk density and amorphous or poorly crystalline chemical constituents in the soil fraction were also examined. The triple beam balance apparatus was successfully used to calculate strength of undisturbed, moist clods. Most...
Oxisols derived from clayey sediments, sandstone, mafic rocks and schist were sampled in the Triangulo Mineiro region, Minas Gerais State, Brazil, to study the relationship between the phosphate adsorption and mineralogy and specific surface area. The specific surface area of the iron oxides estimated from N 2 adsorption by the soil clays before and after dithionite-citrate dissolution...
Soils in mountainous terrain are often thin and unable to store sufficient water to support existing vegetation through dry seasons. This observation has led to speculation about the role of bedrock in supporting plant growth in natural ecosystems, since weathered bedrocks often have appreciable porosity and, like soil, can store and transmit water. This study, within a chaparral ecosystem in southern...
Modern land management increasingly demands quantitative information on spatially variable soil properties. Traditional soil survey maps do not provide this information. In this paper we report on the application of terrain attributes to mapping soil depth classes at high spatial resolution over large areas under dry Mediterranean conditions.Soil data were collected in 111 georeferenced field plots...
Nine soil profiles of a typical toposequence under primary rain forest of the Amazon area were investigated, distinguishing between Geric Ferralsols (Xanthic Kandiudox) in the upper and middle parts of the slope and Geri-Haplic Arenosols (Oxyaquic Quartzipsamments) in the lower ones. Generally, the soils are strongly acid with very high Al contents and show extremely low nutrient contents. In spite...
Silty-to-sandy mantle and laterite sediments overlying bedrock in West Africa (Cameroon to Mali) were studied to establish their origin. Oxygen isotope values of fine quartz (1 to 10 μm in diameter) separated from the samples have a relatively narrow range (+ 15 to + 17‰, vs. SMOW) and are indistinguishable from quartz separated from two Harmattan wind dust samples collected in Nigeria (+ 15.4‰)...
In a glasshouse pot experiment plant: soil concentration ratios (CRs) of 134 Cs were studied in wheat, lucerne, endive, radish, string bean and cucumber. They were grown in eight Greek soil types differing widely in their physical and chemical properties.The CRs of crops and plant parts varied greatly with the soil type and ranged from 0.00019 to 0.126 for wheat grain and from 0...
Soil characteristics and methanogenesis were investigated in Fluvisols of the Balandra lagoon mangrove in Baja California, Mexico in March/April 1995.The grain size distribution was dominated by the silt fraction (54-92%), sand and clay contents were 6-44% and 0-10%, respectively. Bulk density was 0.6-1.5 g cm -3 , the water content 290-690 ml 1 -1 and the air content 38-200...
A simple and efficient method was developed to simulate one-, two- and three-dimensional random fields with one particular kind of variogram for each dimension. The proposed method used an iterative numerical scheme to solve a stochastic differential equation. Since the procedure required minimal computer memory and computation time, it was especially attractive for simulating a large number of...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.