Academic literature on the topic 'Sandy soils – Composition'
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Journal articles on the topic "Sandy soils – Composition"
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Chmiel, Stanisław, Stanisław Hałas, Sławomir Głowacki, Joanna Sposób, Ewa Maciejewska, and Andrzej Trembaczowski. "Concentration of soil CO2 as an indicator of the decalcification rate after liming treatment." International Agrophysics 30, no. 2 (April 1, 2016): 143–50. http://dx.doi.org/10.1515/intag-2015-0085.
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Abstract This paper presents the results of investigation of decalcification of acid sandy and loamy sand soils by infiltration waters, and potential Ca-leaching after liming treatment. For this purpose, monthly measurements were made of the concentration of CO2 in the soil air, dissolved inorganic carbon in the soil waters, and their ionic composition. The determined dissolved inorganic carbon ranged from 5.9 to 10.6 mg dm−3 and from 9.9 to 16.5 mg dm−3 for the sandy and loamy sand soil, respectively. The Ca concentration in soil waters was determined as 5.9-12.4 mg dm−3 in sandy soil and 14.2-19.8 mg dm−3 in soil loamy sand. The calculated rate of decalcification amounted to 23.0 kg ha−1 year−1 in soil sandy and 19.4 kg ha−1 year−1 in loamy sand soil. The potential Ca-leaching is predicted as 124 kg ha−1 year−1 for S and 87 kg ha−1 year−1 for loamy sand soil. At the treatment level of 3 000 kg ha−1 4 year−1 of CaO, ~20% of the Ca-fertilizer can be leached after the liming treatment. The results of the CO2 concentration in the soil air may be useful in estimation of Ca-leaching from soils developed by slightly clayey sands and clayey sands in zones with a moderate climate.
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Kozlova, Irina V., Alexey E. Bespalov, and Olga V. Zemskova. "Modified Composition for Fixing Sandy Soils." Materials Science Forum 992 (May 2020): 143–48. http://dx.doi.org/10.4028/www.scientific.net/msf.992.143.
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The possibility of using a modified composition based on slag Portland cement with the addition of stabilized finely dispersed slag in geotechnical construction and in landscape design is considered. The physical, mechanical and structural characteristics of samples hardening in normal conditions and under the influence of aggressive media were studied. It is established that the compressive and flexural strength of the modified samples is higher than that of the control sample. When hardening in normal conditions, on the first day, the flexural strength of modified specimens increased by 59%, at the grade age by 51%, compressive strength - 2.3 times and by 83%, respectively. When hardening in aggressive media, an increase in the strength of the modified specimens is also observed (flexural by 35–58%, compressive by 7–15%). This is explained by the fact that stabilized slag particles in a hardening system perform two functions: they are centers of directional crystallization for nucleation and growth of newgrowths, and full participants in the hydration process, binding calcium hydroxide to crystallohydrate compounds, thereby preventing the formation of ettringite when the concrete structure is exposed to aggressive media.
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Korolev, Vladimir A., and Elena A. Fedyaeva. "EFFECT OF PHASE COMPOSITION ON THE PARAMETERS OF NON-ISOTHERMAL MOISTURE TRANSFER IN UNSATURATED SANDY SOILS." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 20, no. 1 (March 10, 2014): 95–102. http://dx.doi.org/10.3846/13923730.2013.843584.
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This paper considers the influence of phase composition on the parameters of non-isothermal moisture transfer in unsaturated sandy soils. The technique of study options non-isothermal moisture transfer to disperse soil of disturbed structure. The exploratory procedure of the parameters in disperse soils having disturbed structure in the wide range of their phase composition using triangular diagrams is expounded. Shown that the parameters non-isothermal moisture transfer depend on moisture content and soil composition density. Established that for the sandy soil there is the “optimal” range of moisture content and density at which the non-isothermal moisture transfer is most efficient. The dynamics of the field moisture content of sand in time is identified.
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Urazbaev, I. U., and N. K. Masharipov. "Fundamental Scale of Evaluation of Productivity of Irrigated Gray-Meadow Soils which are Appointed for Growing Melon Crops." Alinteri Journal of Agriculture Sciences 36, no. 1 (May 17, 2021): 257–59. http://dx.doi.org/10.47059/alinteri/v36i1/ajas21038.
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In the following article, the basic scale for assessing the fertility of irrigated gray-meadow soils planted with melons is based on the mechanical composition of the soil. The mechanical composition of the soil correlation coefficient between the yields of melons and gourds was 0.88 for watermelon, 0.89 for melon and 0.88 for pumpkin. Accordingly, light sandy soils for ground watermelon and squash were rated as productive with a score of 100 points, heavy sandy soils with a score of 85 points for watermelon and 75 points for pumpkin. For the melon crop, medium sandy soil was rated at 100 points, heavy sandy soil at 90 points, and light sandy soil at 75 points.
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OLIVEIRA, FERNANDA M. P., JOSÉ DOMINGOS RIBEIRO-NETO, ALAN N. ANDERSEN, and INARA R. LEAL. "Chronic anthropogenic disturbance as a secondary driver of ant community structure: interactions with soil type in Brazilian Caatinga." Environmental Conservation 44, no. 2 (August 19, 2016): 115–23. http://dx.doi.org/10.1017/s0376892916000291.
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SUMMARYHabitat loss is widely recognized as the major cause of global biodiversity decline, but remaining habitat is increasingly threatened by chronic human disturbances. Using a multi-model averaging approach we examined the association between five chronic disturbance surrogates and the richness and taxonomic and functional composition of ants in Brazilian Caatinga. Using pitfall traps in 47 plots near Parnamirim city (Pernambuco) across two soil types (sand and clay), we recorded 53 species from 27 genera. Ant species richness on sand was slightly higher than on clay, and was negatively related to most surrogates of anthropogenic disturbance. Soil type and human population size were the main predictors of ant species richness. Soil type was the most important predictor of functional group abundance. Taxonomic and functional composition were influenced by soil type and disturbance, but this relationship varied between clay and sandy soils. Ant functional composition showed a weak relationship with disturbance on sandy soils, but on clay soils it showed predictable winner–loser replacement. We attribute the greater effect of disturbance on clay soils to higher intensity of land use, and our study highlights the importance of considering context dependence when evaluating biodiversity responses to disturbance.
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Gaiser, Thomas, Frieder Graef, and José Carvalho Cordeiro. "Water retention characteristics of soils with contrasting clay mineral composition in semi-arid tropical regions." Soil Research 38, no. 3 (2000): 523. http://dx.doi.org/10.1071/sr99001.
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In semi-arid tropical regions, the availability of reliable data for water retention in relation to soil type, texture, and organic matter content is low. It would be therefore desirable to develop pedotransfer functions (PTF) in order to estimate water retention characteristics from easily available soil parameters. In the present study, a soil database containing water retention characteristics, particle size distribution, and total organic carbon content of 663 horizons from semi-arid regions in NE Brazil and SE Niger was used to investigate the effect of contrasting clay mineral composition on water retention and PTF characteristics for soils from semi-arid tropical regions. For soil water content at field capacity (–33 kPa) and wilting point (–1500 kPa), PTFs were established and validated with disturbed samples from LAC soils (soils containing predominantly low activity clay; CEC < 24 cmol/kg clay) and non-LAC soils. The PTFs for the LAC soil group differed considerably from the PTFs for non-LAC soils with respect to the contribution of total organic carbon and silt content to the prediction of soil water content at field capacity and wilting point. For the particle size classes sand, loamy sand, sandy loam, and sandy clay loam, the mean measured soil water contents in LAC soils were significantly smaller than in non-LAC soils at a matric potential of –33 kPa. The results demonstrate the influence of clay mineral composition on soil water retention and its importance for the development of pedotransfer functions.
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Xu, Bin Bin, Kentaro Nakai, and Toshihiro Noda. "Propagation Characteristics of Seismic Waves Taking Stratigraphic Composition into Consideration." Advanced Materials Research 989-994 (July 2014): 484–89. http://dx.doi.org/10.4028/www.scientific.net/amr.989-994.484.
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In this paper, soil-water coupled dynamic analyses are carried out to investigate the influence of stratigraphic composition on the propagation properties of the seismic waves. SYS Cam-clay model is used as the constitutive model which can describe the different state of clayey and sandy soils. Two cases are considered for the composition of ground: one is the sandy ground with diluvial sand, alluvial sand and reclaimed sand; the other one is the clayey layer at the ground surface. It is found that for the sandy ground even though there is certain amplification of the input acceleration wave during the dense sand layer the subsequent seismic waves through the loose sand layers are attenuated significantly due to the occurrence of the liquefaction. While for the clayey ground, even though there is no risk of liquefaction damages at the ground surface the acceleration amplitude is greatly amplified and there is a risk that the structure itself would fail in the strength.
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Yost, Jenifer L., Eric E. Roden, and Alfred E. Hartemink. "Geochemical Fingerprint and Soil Carbon of Sandy Alfisols." Soil Systems 3, no. 3 (August 29, 2019): 59. http://dx.doi.org/10.3390/soilsystems3030059.
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Soil carbon storage is affected by particle-size fractions and Fe oxides. We assessed soil carbon concentrations in different particle-size fractions, determined the soil chemical composition of the soil, and weathering and mineralogy of sandy soils of the Wisconsin Central Sands, USA. Three land uses were studied (agriculture, forest, and prairie). The soils contained a minimum of 830 g sand kg−1 up to 190 cm soil depth. Approximately 46% of the sand was in the 250–500 μm fraction, and 5% was <125 μm. Soil carbon ranged from 5 to 13 g kg−1 in the topsoil, and decreased with depth. The <45 μm fraction tended to have high concentrations of carbon, ranging from 19 to 43 g kg−1 in the topsoil. Silicon content was over 191 g Si kg−1, and was lowest in the Bt horizons (191–224 g Si kg−1). Up to 29 g Fe kg−1 and 39 g Al kg−1 were present in the soil, and were highest in the Bt horizons. These soils were mostly quartz, and diopside was found throughout the soil profiles. Weathering indices, such as the Ruxton Ratio, showed that the C horizons were the least weathered and the Bt horizons were more weathered. We conclude that most of the carbon in these soils is held in the <45 μm fraction, and soil carbon and total Fe were lowest in the coarser size fractions.
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Yousfi, Salima, José Marín, Lorena Parra, Jaime Lloret, and Pedro V. Mauri. "A Rhizogenic Biostimulant Effect on Soil Fertility and Roots Growth of Turfgrass." Agronomy 11, no. 3 (March 18, 2021): 573. http://dx.doi.org/10.3390/agronomy11030573.
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The excessive use of chemical fertilizers can lead to severe environmental damages. In recent decades, the application of biostimulants to improve soil composition and stimulate plant growth has contributed significantly to environmental preservation. In this paper, we studied the effect of a rhizogenic biostimulant, obtained from fulvic acids, probiotics, and prebiotics, on the fertility of two types of soils, sandy and sandy loam soils, in which turfgrass was growing. Soil samples from plots treated with biostimulant and controls (untreated plots) were collected. The analyzed parameters from the soil include organic matter, microbial activity, soil chemical composition, catalase, dehydrogenase, and phosphatase enzyme activities. Moreover, root lengths was examined and compared in turfgrass species. The biostimulant application improved microbial activity, organic matter, and enzymatic activity in both types of soils. The soil calcium, potassium, magnesium, and phosphorus content increased with the biostimulant application, whereas pH and electrical conductivity decreased. The most relevant improvement was a 77% increase of calcium for sandy loam soil and 38% increase in potassium for sandy soil. Biostimulant application led to a significant increase in turf root length. This increase was greater for sandy soil than in sandy loam soil with an increment of 43% and 34% respectively, compared to control.
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Zakharov, A. V., and S. E. Makhover. "THE EFFECT GRAIN-SIZE COMPOSITION ON THERMAL CONDUCTIVITY OF SANDY SOILS." Construction and Geotechnics 11, no. 2 (December 15, 2020): 19–27. http://dx.doi.org/10.15593/2224-9826/2020.2.02.
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Today the issue of energy saving is acute. The main sources of energy are radiant energy of the Sun, wind energy, energy of moving water. Therefore, the issue of solving alternative energy sources is relevant. The article aims to solve the problem by using low-potential heat of the soil mass by means of energy-efficient building constructions - foundations. It is necessary to know the thermal characteristics of soils for this. At the moment, methods for determining the thermophysical properties of inert materials with subsequent practical application in the field of construction have been widely studied, but no one of these methods takes into account the grain-size composition. Thus, the study of the connection between the thermal conductivity and the grain-size composition of the soil is important. The aim of the work is to Estimation of thermal conductivity of sandy soils based on grain-size composition. This article presents an analysis of the dependence of the thermal conductivity of the sandy soil of its grain-size composition. The matrix of experiment planning is made; the methodology and technological sequence of the experiment were tested. Statistical processing of the obtained experimental data was carried out. Based on a series of test experiments, it was concluded that there are two factors competing in its thermal conductivity: an increase in λ due to an increase in the degree of pore filling and a decrease in total heat conductivity due to a decrease in the degree of pore filling. These results suggest that grain-size composition has an impact on the thermal conductivity of the sandy soil. During the experiment, the dependence of the thermal conductivity of sandy soils on their grain-size composition was experimentally established.
Dissertations / Theses on the topic "Sandy soils – Composition"
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Zakharova, Anna. "Soil organic matter dynamics: influence of soil disturbance on labile pools." Thesis, University of Canterbury. School of Biological Sciences, 2014. http://hdl.handle.net/10092/9944.
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Soils are the largest pool of carbon (C) in terrestrial ecosystems and store 1500 Gt of C in their soil organic matter (SOM). SOM is a dynamic, complex and heterogeneous mixture, which influences soil quality through a wide range of soil properties. Labile SOM comprises a small fraction of total SOM (approximately 5%), but due to its rapid turnover has been suggested to be most vulnerable to loss following soil disturbance. This research was undertaken to examine the consequences of soil disturbance on labile SOM, its availability and protection in soils using the isotopic analysis of soil-respired CO₂ (δ¹³CO₂).
A range of soils were incubated in both the short- (minutes) and long-term (months) to assess changes in labile SOM. Shifts in soil-respired δ¹³CO₂ over the course of soil incubations were found to reflect changes in labile substrate utilisation. There was a rapid depletion of δ¹³CO₂ (from a starting range between -22.5 and -23.9‰, to between -25.8 and -27.5‰) immediately after soil sampling. These initial changes in δ¹³CO₂ indicated an increased availability of labile SOM following the disturbance of coring the soil and starting the incubations. Subsequently δ¹³CO₂ reverted back to the initial, relatively enriched starting values, but this took several months and was due to labile SOM pools becoming exhausted.
A subsequent study was undertaken to test if soil-respired δ¹³CO₂ values are a direct function of the amount of labile SOM and soil physical conditions. A range of pasture soils were incubated in the short-term (300 minutes), and changes in soil-respired δ¹³CO₂ were measured along with physical and chemical soil properties. Equilibrium soil-respired δ¹³CO₂, observed after the initial rapid depletion and stabilisation, was a function of the amount of labile SOM (measured as hot water extractable C, HWEC), total soil C and soil protection capacity (measured as specific soil surface area, SSA). An independent experimental approach to assess the effect of SSA, where labile SOM was immobilised onto allophane – a clay mineral with large, active surface area – indicated limited availability of labile SOM through more enriched δ¹³CO₂ (in a range between -20.5 and -20.6 ‰) and a significant (up to three times) reduction in HWEC.
In the third study, isotopic measurements were coupled with CO₂ evolution rates to directly test whether equilibrium soil-respired δ¹³CO₂ can reflect labile SOM vulnerability to loss. Soils were sampled from an experimental tillage trial with different management treatments (chemical fallow, arable cropping and permanent pasture) with a range of C inputs and soil disturbance regimes. Soils were incubated in the short- (300 minutes) and long-term (600 days) and changes in δ¹³CO₂ and respiration rates measured. Physical and chemical fractionation methods were used to quantify the amount of labile SOM. Pasture soils were characterised by higher labile SOM estimates (HWEC; sand-sized C; labile C respired during long-term incubations) than the other soils. Long-term absence of plant inputs in fallow soils resulted in a significant depletion of labile SOM (close to 50% based on sand-sized C and HWEC estimates) compared with pasture soils. The values of δ¹³CO₂ became more depleted in 13C from fallow to pasture soils (from -26.3 ‰ to -28.1 ‰) and, when standardised (against the isotopic composition of the solid soil material), Δ¹³CO₂ values also showed a decrease from fallow to pasture soils (from -0.3 ‰ to -1.1 ‰). Moreover, these patterns in isotopic measures were in strong agreement with the amount of labile SOM and its availability across the soils, and were best explained by the isotopic values of the labile HWEC fraction.
Collectively, these results confirm that labile SOM availability and utilisation change immediately after soil disturbance. Moreover, isotopic analysis of soil-respired CO₂ is a powerful technique, which enables us to probe mechanisms and examine the consequences of soil disturbance on labile SOM by reflecting its availability and the degree of SOM protection.
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Diouf, Babou. "Use of bentonite to stabilize sandy soil material in a wind tunnel study." 1986. http://hdl.handle.net/2097/27618.
Full textBook chapters on the topic "Sandy soils – Composition"
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Breuninger, Ray H., Dale A. Gillette, and Rolf Kihl. "Formation of Wind-Erodible Aggregates for Salty Soils and Soils with Less Than 50% Sand Composition in Natural Terrestrial Environments." In Paleoclimatology and Paleometeorology: Modern and Past Patterns of Global Atmospheric Transport, 31–63. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-009-0995-3_2.
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Juo, Anthony S. R., and Kathrin Franzluebbers. "Soil Physics." In Tropical Soils. Oxford University Press, 2003. http://dx.doi.org/10.1093/oso/9780195115987.003.0007.
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Soil physics deals with physical properties of soils such as soil texture, porosity, soil water, soil aeration, soil temperature, soil structure, and the influence of these properties on plant growth. Soil texture refers to the particle-size distribution of soils. The primary soil particles are arbitrarily divided into different size classes. The International Society of Soil Science defines soil particles larger than 0.02 mm and smaller than 2 mm as sand, those larger than 0.002 mm but smaller than 0.02 mm as silt, and those smaller than 0.002 mm as clay. Soil particles larger than 2 mm, such as gravel and stones, are called coarse fragments and are not part of the soil itself, to which the term soil texture applies, but can have considerable influence on soil properties and plant growth. Sand particles (0.02-2 mm) can be further divided into fine sand (0.02-0.2 mm) and coarse sand (0.2-2 mm). Sand particles can be rounded or angular, and are noncohesive. They usually consist of a single mineral, usually quartz (SiO2) or other primary silicate, and may appear brown, yellow, or red as a result of Fe-oxide coatings. Due to its mineral composition, sand has a smaller plant-nutrient content than finer soil particles. Sand particles have large voids between them which promote drainage of water and entry of air into the soil. Due to their low specific surface area, sand particles can hold little water, therefore rain needs to be received at short intervals to enable plant growth on sandy soils. Silt particles (0.002-0.02 mm) do not feel gritty when rubbed between fingers and are not visible to the unaided eye as sand particles are. Quartz is generally the dominant mineral. However, when silt is composed of weatherable minerals, the release of plant nutrients can be significant. The pores between silt particles are smaller and more numerous than those in sand, and silt therefore retains more water than sand, which helps to sustain plant growth. Silt itself does not exhibit much stickiness or plasticity and is therefore easily washed away by water. If silt fractions have some cohesion and adsorptive capacity, it is due to a film of adhering clay particles.
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Yu, T. R. "Introduction." In Chemistry of Variable Charge Soils. Oxford University Press, 1997. http://dx.doi.org/10.1093/oso/9780195097450.003.0004.
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The constitution and properties of soils have their macroscopic and microscopic aspects. Macroscopically, the profile of a soil consists of several horizons, each containing numerous aggregates and blocks of soil particles of different sizes. These structures are visible to the naked eye. Microscopically, a soil is composed of many kinds of minerals and organic matter interlinked in a complex manner. In addition, a soil is always inhabited by numerous microorganisms which can be observed by modern scientific instruments. To study these various aspects, several branches of soil science, such as soil geography, soil mineralogy, and soil microbiology, have been developed. If examined on a more minute scale, it can be found that most of the chemical reactions in a soil occur at the interface between soil colloidal surface and solution or in the solution adjacent to this interface. This is because these colloidal surfaces carry negative as well as positive charges, thus reacting with ions, protons, and electrons of the solution. The presence of surface charge is the basic cause of the fertility of a soil and is also the principal criterion that distinguishes soil from pure sand. The chief objective of soil chemical research is to deal with the interactions among charged particles (colloids, ions, protons, electrons) and their chemical consequences in soils. As depicted in Fig. 1.1, these charged particles are closely interrelated. The surface charge of soil colloids is the basic reason that a soil possesses a series of chemical properties. At present, considerable knowledge has been accumulated about the permanent charge of soils. On the other hand, our understanding is still at an early stage about the mechanisms and the affecting factors of variable charge. The quantity of surface charge determines the amount of ions that a soil can adsorb, whereas the surface charge density is the determining factor of adsorbing strength for these ions. Because of the complexities in the composition of soils, the distribution of positive and negative charges is uneven on the surface of soil colloidal particles. Insight into the origin and the distribution of these charges should contribute to a sound foundation of the surface chemistry of soils.
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White, Robert E. "The Makeup of Soil." In Soils for Fine Wines. Oxford University Press, 2003. http://dx.doi.org/10.1093/oso/9780195141023.003.0004.
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Minerals and organic matter comprise the solid phase of the soil. The geological origin of the soil minerals, and the input of organic matter from plants and animals, are briefly discussed in section 1.2.1. A basic knowledge of the composition and properties of these materials is fundamental to understanding how a soil influences the growth of grapevines. A striking feature of soil is the size range of the mineral matter, which varies from boulders (>600 mm diameter), to stones and gravel (600 to >2 mm diameter), to particles (<2 mm diameter)—the fine earth fraction. The fine earth fraction is the most important because of the type of minerals present and their large surface areas. The ratio of surface area to volume defines the specific surface area of a particle. The smaller the size of an object, the larger is the ratio of its surface area to volume. This can be demonstrated by considering spherical particles of radius 0.1 mm, 0.01 mm, and 0.001 mm (1 micrometer or micron, μm). The specific surface areas of these particles are 30, 300, and 3000 mm2/mm3, respectively. In practice, the specific surface area is measured as the surface area per unit mass, which implies a constant particle density (usually taken as 2.65 Mg/m3). A large specific surface area means that more molecules can be adsorbed on the surface. Representative values for the specific surface areas of sand, silt, and clay-size minerals are given in table 2.1. Note the large range in specific surface area, even for the clay minerals, from as little as 5 m2/g for kaolinite to 750 m2/g for Na-montmorillonite. Because specific surface areas are important, we need to know the size distribution of particles in the fine earth fraction. This is expressed as the soil’s texture. The types of minerals that make up the individual size fractions are also important because they too influence the reactivity of the surfaces. Both these topics are discussed here. All soils show a continuous distribution of particle sizes, called a frequency distribution. This distribution relates the number (or mass) of particles of a given size to their actual size, measured by the diameter of an equivalent sphere.
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Cuevas, Elvira. "Soil versus Biological Controls on Nutrient Cycling in Terra Firme Forests." In The Biogeochemistry of the Amazon Basin. Oxford University Press, 2001. http://dx.doi.org/10.1093/oso/9780195114317.003.0007.
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Terra firme forests are those that by definition are not permanently or seasonally flooded (terra firme meaning “firm terrain”). This type of forest encompasses the Amazon and Orinoco basins, stretching from the lower slopes of the Andes, east to the Guianas, and south to about 15°S in western Brazil and northern Bolivia (Richards 1996). Structural and compositional variability in these forests in the Amazon basin is very wide as a result of climate differences and geomorphological position. The region is not climatically uniform; the central and much of the southern parts have less and more seasonal rainfall than the eastern and western parts (Walsh 1996). These differences have direct and indirect ecological significance, as phenology and biological processes related to nutrient availability will be strongly influenced by both factors (Cuevas and Medina 1986, 1988, 1990, Medina and Cuevas 1989). Periods of two or more consecutive dry days are ecologically significant in a humid area such as San Carlos de Río Negro, in the northern part of the Amazon, because of low water retention capacity in the widespread sandy soils. In lower geomorphological positions, dry spells of 5-10 days may result in fluctuations of the water table from 0.4-1.0 m (Herrera 1977, Bongers et al. 1985). In areas with a more strongly seasonal climate, roots have been found extending to 18 m depth (Nepstad et al. 1995). This may explain the presence of evergreen forest in the seasonally dry eastern Amazon. Structure and physiognomy of terra firme forests is very similar throughout Amazonia, but floristically it is quite variable due to different compositions in the subbasins of the Amazon’s major tributaries. These subbasins are located within geochemical regions that can be differentiated based on the physicochemical properties of drainage waters (Sioli 1975, Fittkau 1971, Fittkau et al. 1975). Blackwater rivers, such as the Río Negro, drain mostly sandy podsolized soils low in most essential nutrients for plant growth. They are characterized by a high content of humic acids, which remain dissolved because of the predominant low concentrations of polyvalent cations, mainly Ca2+ and Mg2+.
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Maun, M. Anwar. "Zonation and succession." In The Biology of Coastal Sand Dunes. Oxford University Press, 2009. http://dx.doi.org/10.1093/oso/9780198570356.003.0017.
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There is ample evidence that a progressive change in the intensity of an important environmental factor leads to the formation of zones or belt-like communities in which the plant species reflect a fairly distinct range of tolerance for that factor (Daubenmire 1968). Zonation has been defined as a sequence of vegetation in space and succession as a sequence of vegetation in time (McIntosh 1980). A zone is an area occupied by a plant community that is distinctly different from other zones and can be readily recognized by a change in dominant vegetation. Striking examples of zonation are found in salt marshes, mountain slopes and ponds because of soil salinity in salt marshes, decrease in temperature on mountain slopes and increase in water depth in ponds (Daubenmire 1968; Chapman 1976; Partridge and Wilson 1988). Similarly, it has long been known (Beck 1819) that sand dunes along sea coasts exhibit a zonation pattern extending from the beach to inland dunes. The zones are discrete and occur in parallel series with distinctly different species composition that is related to the ability of plant species to withstand the environmental factors prevailing in that zone (Doing 1985). Many later studies using transects from the shoreline to the inland dunes have confirmed that the taxa are not randomly distributed; they peak at definite distances from the beach (Oosting and Billings 1942; Boyce 1954; Martin 1959; Barbour 1978; Barbour et al. 1985). Succession in coastal dunes is an example of primary succession because the sandy material deposited on the shoreline by waves is inert. The term is generally used to denote a directional change in species composition and physiognomy of vegetation at the same site over time (Drury and Nisbet 1973). However, only the very early stages of dune succession can be observed during the life time of a plant ecologist and the later stages are usually inferred from plant communities represented on older sand dunes. It is hypothesized that the autogenic influence of early colonizers alters environmental conditions in the habitat and facilitates the establishment of new species better adapted to live in the altered habitat.
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Peters, Debra P. C., and Robert P. Gibbens. "Plant Communities in the Jornada Basin: The Dynamic Landscape." In Structure and Function of a Chihuahuan Desert Ecosystem. Oxford University Press, 2006. http://dx.doi.org/10.1093/oso/9780195117769.003.0014.
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Plant communities of the Jornada Basin are characteristic of the northern Chihuahuan Desert both in structure and dynamics. Although a number of plant communities can be differentiated, five major vegetation types are often distinguished that differ in plant species cover and composition, as well as other factors, such as animal populations, soil properties, and elevation. These five types are black grama (Bouteloua eriopoda) grasslands, playa grasslands, tarbush (Flourensia cernua) shrublands, creosotebush (Larrea tridentata) shrublands, and mesquite (Prosopis grandulosa) shrublands. Similar to many other parts of the Chihuahuan Desert, these plant communities have experienced major shifts in vegetation composition over the past 50–150 years (York and Dick-Peddie 1969). The most dramatic changes in vegetation and associated ecosystem processes have occurred as a result of a shift in life form due to woody plant encroachment into perennial grasslands (Grover and Musick 1990; Bahre and Shelton 1993). This encroachment of shrubs has occurred in many arid and semiarid regions of the world, including the Western United States, northern Mexico, southern Africa, South America, New Zealand, and Australia (McPherson 1997; Scholes and Archer 1997). A number of drivers have been implicated in these grass–shrub dynamics, including various combinations of livestock grazing, small animal activity, drought, changes in fire regime, and changes in climate (Humphrey 1958; Archer 1989; Allred 1996; Reynolds et al. 1997; Van Auken 2000). The causes of shrub invasion are quite variable and often poorly understood, although the consequences consistently lead to the process of desertification (Schlesinger et al. 1990). This chapter describes the characteristics of each vegetation type and the documented changes in each type at the Jornada Basin. We then discuss the key drivers influencing these dynamics. Vegetation in the Chihuahuan Desert region has been classified as desert-grassland transition (Shreve 1917), desert savanna (Shantz and Zon 1924), desert plains grasslands (Clements 1920), desert shrub grassland (Darrow 1944), and shrubsteppe (Kuchler 1964). Desert grassland is often used as a general descriptive name for the area (McClaran 1995), although landscapes at the Jornada and throughout the northern Chihuahuan Desert often consist of a mosaic of desert grasslands, Chihuahuan Desert shrublands, and plains-mesa sand scrub (Dick-Peddie 1993).
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Hussaini Jagaba, Ahmad, Shamsul Rahman Mohamed Kutty, Gasim Hayder Ahmed Salih, Azmatullah Noor, Mohammad Fakhuma Ubaidillah bin Md Hafiz, Nura Shehu Aliyu Yaro, Anwar Ameen Hezam Saeed, Ibrahim Mohammed Lawal, Abdullahi Haruna Birniwa, and Abdullahi Usman Kilaco. "Palm Oil Clinker as a Waste by-Product: Utilization and Circular Economy Potential." In Elaeis guineensis [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.97312.
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Conservation of natural resources to create ecological balance could be significantly improved by substituting them with waste by-products. Palm oil industry operations increases annually, thereby generating huge quantity of waste to be dumped into the landfill. Palm oil clinker (POC) is a solid waste by-product produced in one of the oil palm processing phases. This chapter is designed to highlight the generation, disposal problems, properties and composition of POC. The waste to resource potentials of POC would be greatly discussed in the chapter starting with the application of POC in conventional and geopolymer structural elements such as beams, slabs, columns made of either concrete, mortar or paste for coarse aggregates, sand and cement replacement. Aspects such as performance of POC in wastewater treatment processes, fine aggregate and cement replacement in asphaltic and bituminous mixtures during highway construction, a bio-filler in coatings for steel manufacturing processes and a catalyst during energy generation would also be discussed. Circular economy potentials, risk assessment and leaching behavior during POC utilization would be evaluated. The chapter also discusses the effectiveness of POC in soil stabilization and the effect of POC pretreatment for performance enhancement. Towards an efficient utilization, it is important to carry out technical and economic studies, as well as life cycle assessments, in order to compare all the POC areas of application described in the present review article. POC powder has proven to be pozzolanic with maximum values of 17, 53.7, 0.92, 3.87, 1.46, for CaO, SiO2, SO3, Fe2O3 and Al2O3. Therefore, the present chapter would inspire researchers to find research gaps that will aid the sustainable use of agroindustry wastes. The fundamental knowledge contained in the chapter could also serve as a wake-up call for researchers that will motivate them to explore the high potential of utilizing POC for greater environmental benefits associated with less cost when compared with conventional materials.
Conference papers on the topic "Sandy soils – Composition"
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Dima, Milica, Aurelia Diaconu, Reta Drăghici, Drăghici Iulian, and Matei Gheorghe. "ASPECTS CONCERNING PEANUTS CROPS ON SANDY SOILS IN SOUTHERN OLTENIA." In GEOLINKS Conference Proceedings. Saima Consult Ltd, 2021. http://dx.doi.org/10.32008/geolinks2021/b1/v3/34.
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"For the capitalization of the climate and soil conditions for the sandy soil region in Southern Oltenia by cultivating peanuts it is necessary to use varieties with large production abilities and proper technology for the crops. In view of its cultivation on south Oltenia sandy soils, there were carried out in the period 2004-2006, at the Plants Crops Research and Development Station on Sandy Soils Dabuleni, experiments have been set regarding aspects such as: the optimal seeding period, the recommendation varieties with high yield potential and balanced composition. The research was conducted under irrigation conditions, in a three-year rotation of wheat, peanut, maize. Along with erect growth type varieties, known for their short vegetation period, rising and creeping growth type varieties can also be used; these varieties have a great production potential in our country`s conditions. Establishing the proper time for seeding is espe since sandy soils are heating quickly but are also cooling quickly, the best seeding time is between the end of April- the beginning of May, depending on the date when the seeding depth has a steady temperature, minimal required for the seed to germinate."
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Mackevičius, Rimantas, Danutė Sližytė, Tatyana Zhilkina, and Vadim Turchin. "Investigation of influence of additives on properties of multi-molecular organic solutions used for permeation grouting." In The 13th international scientific conference “Modern Building Materials, Structures and Techniques”. Vilnius Gediminas Technical University, 2019. http://dx.doi.org/10.3846/mbmst.2019.112.
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Permeation grouting for stabilization of dispersive sandy and gravely soils is in use from beginning of 19th century and has high importance for various underpinning, tunneling, and structural strengthening works. As materials for permeation grouting are applied not only cement mortar or silica gel in many compositions but multi-molecular organic solutions too. From multi-molecular organic solutions for permeation grouting are in use various synthetic resins such as acrylic, urea-formaldehyde, or other polymer resins. Urea-formaldehyde resin has right physical and mechanical properties for applying in soil stabilization but additives can change these properties. For example, additives can increase density, pH-rate, and gel-formation time of urea-formaldehyde resin. Additives can decrease viscosity of solutions based on urea-formaldehyde resin. Additives can improve environmental aspects of use of multi-molecular organic solutions for grouting of sandy soils. Long-time investigations of influence of additives on properties of multi-molecular organic solutions used for soil stabilization give good results for optimization of composition of materials for grouting.
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Dashko, Regina, and Ivan Alekseev. "Underground Space of Saint-Petersburg as a Multicomponent System: Engineering Geological and Geotechnical Aspects of its Development." In The 13th Baltic Sea Region Geotechnical Conference. Vilnius Gediminas Technical University, 2016. http://dx.doi.org/10.3846/13bsgc.2016.008.
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The paper offers a complex approach to assess underground space as a multi-component system for its development and utilization. It is indicated that a geotechnical analysis of sandy and clayey soils of St. Petersburg needs to be carried out based on two models, i.e. one for a jointed and blocky environs and the other for fine-pored media. It has been established that chemical composition of the ground water in the city is characterized with a high content of alkaline-earth elements, which proves the intensive destruction of construction materials, as well as with presence of organic substances judging by the chemical oxygen demand (COD) and biological oxygen demand in 5 days (BOD5). For the first time ever, a microbiotic component has been distinguished which determines the following phenomena: 1) alteration of physical and mechanical properties of sandy and clayey soils; 2) development of flowing sand and thixotropic phenomena; 3) biocorrosion of various construction materials. It is stated that even consolidated morainic soils usually viewed as a safe foundation and media for structures of various applications are transformed into weak and easy-deformable materials characterized with low strength in conditions of intensive contamination.
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Marin, Soare. "RESULTS CONCERNING THE PRODUCTIVE CAPACITY AND CHEMICAL COMPOSITION OF GROUNDNUTS CULTIVATED ON THE SANDY SOILS FROM SOUTHERN ROMANIA." In 14th SGEM GeoConference on NANO, BIO AND GREEN � TECHNOLOGIES FOR A SUSTAINABLE FUTURE. Stef92 Technology, 2014. http://dx.doi.org/10.5593/sgem2014/b61/s25.066.
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Paraschiv, Alina-Nicoleta, Milica Dima, Aurelia Diaconu, Elena Ciuciuc, and Mihaela Croitoru. "RESEARCH ON THE BEHAVIOR OF AN ASSORTMENT OF BELL PEPPER ON THE SANDY SOILS IN SOUTH-WEST OLTENIA ACCORDING TO THE CULTIVATION METHOD USED." In GEOLINKS Conference Proceedings. Saima Consult Ltd, 2021. http://dx.doi.org/10.32008/geolinks2021/b1/v3/40.
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The pedo-climatic conditions specific to sandy soils in southwest Oltenia determine differences in performing different phenophases of growth and development of plants, both between varieties and in the physiological behavior of the same variety under different yield conditions. Therefore, at the Dăbuleni Research and Development Station for Plant Culture on Sands, research was carried out on some physiological, biochemical and production processes at five varieties of bell peppers cultivated in the open fields and solar. Determinations of photosynthesis, foliar transpiration, the biochemical composition of fruits, quantity, and quality of bell pepper production were performed. The physiological and biochemical processes studied were influenced by the environmental conditions specific to each cultivation method, but also by the studied variables. Of the 5 varieties studied, the best results on the biochemical composition of the fruits were recorded at the Artim variety (8.83% total dry substance, 4.60% soluble dry substance, 0.19% acidity, 3.80% carbohydrate and 36.96% vitamin C). The production was between 15,387 t / ha for open-field plants and 108,574 t / ha for plants grown in the solar, the differences between the two cultivation methods being statistically assured as distinctly significant.
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MAZHAYSKY, Yuri, Tatyana GUSEVA, and Otilija MISECKAITĖ. "INTEGRATED MELIORATION MEASURES ON RESTORATION OF POLLUTED AND DEGRADED SOILS FERTILITY." In Rural Development 2015. Aleksandras Stulginskis University, 2015. http://dx.doi.org/10.15544/rd.2015.044.
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In case of significant technogenic geochemical loads on agricultural landscapes, the issue of ecological forecasting of environmental management is particularly important. Scientific studies of this issue are aimed at establishing the critical values for the components of the ecosystem, the classification of technogenic sources of hazardous substances, levels of soil contamination. This study presents a research to determine the content of heavy metals in the soils of the Ryazan region (Russia) and analyzed the level of their pollution. In the experiments organic, organomineral and mineral fertilizers systems were studied. From 2002 to 2008 were conducted lysimetric experiments on detoxification of elevated pollution of sod-podzol sandy loam soil, and from 2006 to 2008 of podzolized black soil. The participation of the non-ferrous metals plant emissions was detected in the pollution of sod-podzol light in granulometric composition soils with copper of up to 80 mg·kg-1, when the average concentration of Cu in the soil was 38.8 ±6 mg·kg-1. Humification plays a significant role in the formation of soil, its most important properties and characteristics. The saturation of 1 hectare of sown area with organic was slightly different in the experiments, but the intensity of accumulation of humus from the various agrochemical means did not almost differ. The problem of adaptation of plants in the conditions of technogenic environment is of primary importance. Plants have three biobarera against the admission of toxicants, these are the soil – the root – the stem – the reproductive organs. Grain in contaminated soil is environmentally hazardous as the content of Pb is indicated at the level of 0.68, 1.17 mg·kg-1 (MPC 0.5), Cd – 0.27, 0.11 mg·kg-1 (MPC 0.1), Zn – 76 mg·kg-1 (50 MPC). Use of fertilizing systems had a mostly positive effect, but products do not always become environmentally friendly.
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Popova, L. D., and I. N. Yudina. "Influence of planting material size on Jerusalem artichoke yield during autumn planting." In Растениеводство и луговодство. Тимирязевская сельскохозяйственная академия, 2020. http://dx.doi.org/10.26897/978-5-9675-1762-4-2020-170.
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The results of the influence of the mass of planting tubers of Jerusalem artichoke on the size and fractional composition of the crop of tubers in the conditions of sod-podzolic sandy loam soils during autumn planting of tubers are presented. It was found that planting tubers weighing 80-100 g g provide a yield of 45 t/ha. With an increase in the mass of planting tubers, the cost of purchasing planting material increases sharply and profitability decreases. Planting small tubers leads to a decrease in yield.
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Голодная, О. М., and Е. А. Жарикова. "FEATURES OF TEXURE OF SOILS OF THE KHANKAISKIY NATURE RESERVE." In Геосистемы Северо-Восточной Азии. Crossref, 2021. http://dx.doi.org/10.35735/tig.2021.41.82.013.
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Изучение гранулометрического состава почв Ханкайского заповедника показало, что профили почв представляют собой многослойные спектры различного литологического сложения. Сложность почвенных профилей по гранулометрическому составу определяется степенью проявления поемного и аллювиального процессов, литологическими особенностями почвообразующего материала. По типу сложения выделено несколько литологических групп. Темно-гумусовые глеевые, аллювиальные луговые глеевые почвы и буроземы глееватые отличаются резкой дифференциацией профиля по гранулометрическому составу на верхнюю легкую и нижнюю глинистую толщу. Для этих почв отмечено наибольшее содержание фракций физической глины и ила по всему почвенному профилю. Буроземы типичные и аллювиальные луговые глееватые, вышедшие из зоны затопления, характеризуются литологически однородным легким составом. В этих почвах выявлено высокое содержание фракций мелкого песка. The soil profiles the Khankaiskiy Nature Reserve represent multilayer spectra of various lithological addition. The complexity of soil profiles in terms of particle-size distribution is determined by the degree of manifestation of soil and alluvial processes, lithological features of soil-forming material. Several lithological groups are distinguished by the type of texture. Dark humus gley, alluvial meadow gley soils and burozem gleyic shrouds are distinguished by a sharp differentiation of the profile by granulometric composition into an upper light and lower clay thickness. The largest content of fractions of physical clay and silt was noted throughout the profiles for these soils. Burozem typical and alluvial meadow gleyic soils that have emerged from the flood zone characterize this with a lithologically homogeneous light composition. A high content of fine sand fractions was revealed in these soils.
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Lehane, Barry M., J. Antonio H. Carraro, Nathalie Boukpeti, and Sarah Elkhatib. "Mechanical Response of Two Carbonate Sediments From Australia’s North West Shelf." In ASME 2014 33rd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/omae2014-23340.
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The carbonate sediments found offshore on the North West Shelf of Australia can generally be described as silts with varying proportions of clay-sized and sand-sized carbonate particles. This paper investigates the undrained shearing response (as measured under simple shear and triaxial conditions) of two sediments with different grading curves. The importance of the fines content in controlling the density and hence dilatancy and undrained strength of the materials is demonstrated. The paper discusses the importance of fabric to the behavior of these soils and provides guidance on how undrained strengths of soils of this nature may be assessed with a knowledge of a material’s in-situ water content (or void ratio) and composition.
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Baranoski, Gladimir V. G., Bradley W. Kimmel, Petri Varsa, and Mark Iwanchyshyn. "What Can Terrestrial Sand-Textured Soils Reveal About the Composition of Core Materials Forming Martian Regolithƒ." In IGARSS 2019 - 2019 IEEE International Geoscience and Remote Sensing Symposium. IEEE, 2019. http://dx.doi.org/10.1109/igarss.2019.8900161.
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