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1
Hamad, Asal Mahmud, e Mahmood Gazey Jassam. "A Comparative Study for the Effect of Some Petroleum Products on the Engineering Properties of Gypseous Soils". Tikrit Journal of Engineering Sciences 29, n. 3 (15 ottobre 2022): 69. http://dx.doi.org/10.25130/tjes.29.3.7.
Testo completoAbstract (sommario):
Gypseous soils are considered problematic soils because the soil cavities happen during receiving the water or this type of soil and solving gypsum materials and contract in a soil volume. In this study, three types of gypseous soils are used; soil1, soil2, and soil3 with gypsum content (28.71%, 43.6%, and 54.88%) respectively, petroleum products (engine oil, fuel oil, and kerosene) are added to the soils with percentages (3%, 6%, 9%, and 12%) for each product. The result showed that specific gravity, liquid limit, optimum moisture content (O.M.C), and maximum dry density decreased with an increased percentage of product for all types of products. The direct shear (dry and soaked case) results show that increasing the (angle of internal friction and the soil cohesion) for soil1, soil2, and soil3 by adding engine oil and fuel oil. Still, when the soils were treated with kerosene, the angle of internal friction increased while cohesion decreased. The collapse potential for the treated soils increases with increasing gypsum content for all petroleum products. The collapse potential (CP) for (soil1) decreased by 47% when using 6% of the engine oil, 48.8% when using 9% of the fuel oil, and 55% when using 9% of the kerosene. The same percentage of the petroleum products (engine oil, fuel oil, and kerosene) decrease the collapse potential for (soil2), (47%, 46%, and 50%) respectively and decrease the collapse potential for (soil 3), (51%, 47.7%, and 52%) respectively. In the unconfined compressive test applied on (soil1) using maximum density, the results show that the soil strength increased (26% and 10%) when using 6% and engine oil and fuel oil, respectively, while the soil strength decreased by 29% when treated with 9% of kerosene.
2
Brodský, L., A. Klement, V. Penížek, R. Kodešová e L. Borůvka. "Building soil spectral library of the Czech soils for quantitative digital soil mapping". Soil and Water Research 6, No. 4 (28 novembre 2011): 165–72. http://dx.doi.org/10.17221/24/2011-swr.
Testo completoAbstract (sommario):
Spectral libraries are the data archives of spectral signatures measured on natural and/or man-made materials. Here, the objective is to build a soil spectral library of the Czech soils (SSL-CZ). Further on, the overall aim is to apply diffuse reflectance spectroscopy as a tool for digital soil mapping. An inevitable part of the library is a metadata database that stores the corresponding auxiliary information on the soils: type of material (soil, parent material), sample preparation, location of the sample with geographic coordinates, soil classification, morphological features, soil laboratory measurements – chemical, physical, and potential biological properties, geophysical features of and climatological information on the sample location. The metadata database consists of seven general tables (General, Spatial, Soil class, Environmental, Auxiliary, Analytical and Spectra) relationally linked together. The stored information allows for a wide range of analyses and for modelling developments of digital soil mapping applications. An example of partial least-square regression (PLSR) modelling for soil pH and clay content with 0.84 and 0.68 coefficients of determination is provided on the subset of the collected data. Currently, the SSL-CZ database contains more than 500 records in the first phase of development. Spectral reflectance signatures are stored in the range of 350 to 2500 nm with a step of 1 nm measured by ASD FieldSpec 3. The soil spectral library developed is fully compatible with Global Soil Spectral Library (Soil Spectroscopy Group).
3
Poyon Kizi, Khayitova Sanobar. "SOIL SCIENCE AND SOIL TERMINOLOGY". European International Journal of Multidisciplinary Research and Management Studies 02, n. 11 (1 novembre 2022): 42–44. http://dx.doi.org/10.55640/eijmrms-02-11-12.
Testo completoAbstract (sommario):
Soil science involves the study of the formation and distribution of soil, the biological, chemical and physical properties and processes of soil and how these processes interact with wider systems to help inform environmental management, industry and sustainable development.
4
Najafi-Ghiri, M., e A. Abtahi. "Potassium fixation in soil size fractions of arid soils". Soil and Water Research 8, No. 2 (15 maggio 2013): 49–55. http://dx.doi.org/10.17221/52/2012-swr.
Testo completoAbstract (sommario):
Amounts of potassium (K) fixed in soil fractions of 10 calcareous soils of southern Iran were measured to evaluate the contributions of different soil size fractions to K fixation. Soil particles were fractionated after dispersion of the soils with an ultrasonic probe. Potassium fixation analysis was done by addition of 1000 mg K/kg samples. Mineralogy of the size fractions was determined by X-ray diffraction. The clay fractions were dominated by smectite, chlorite, mica, and palygorskite. Potassium fixation capacities ranged from 104 to 148 mg/kg for clay, from 102 to 155 mg/kg for silt, and from 96 to 187 mg/kg for sand fractions. A positive and significant relationship (P < 0.05) was obtained between K fixation capacity and smectite content for the clay fractions. High amounts of K fixed in the sand fraction may be explained by a larger diffusion path of fixed K out of the frayed edges of micaceous and smectitic minerals into the extracting solution, low cation exchange capacity (CEC) of the coarse fraction and thereby the high concentration gradient along solution and interlayers, physical entrapment of K ions in coarse aggregates cemented by carbonates, and by the presence of clay particles in coarse fractions due to incomplete dispersion of coarse aggregates.
5
Aitken, RL, e PW Moody. "Interrelations between soil pH measurements in various electrolytes and soil solution pH in acidic soils". Soil Research 29, n. 4 (1991): 483. http://dx.doi.org/10.1071/sr9910483.
Testo completoAbstract (sommario):
Ninety soil samples (81 surface, 9 subsurface) were collected from eastern Queensland and soil pH (1:5 soi1:solution) was measured in each of deionized water (pH,), 0.01 M CaCl2, 0-002 M CaCl2 and 1 M KCl. Soil solution was extracted from each soil after incubation for 4 days at the 10 kPa matric suction moisture content, and pH (pHss) and electrical conductivity were measured. The objectives of this work were to investigate interrelationships between soil pH measurements in various electrolytes and soil solution pH in a suite of predominantly acidic soils. Although the relationships between pHw and pH measured in the other electrolytes could be described by linear regression, the fitting of quadratic equations improved the coefficients of determination, indicating the relationships were curvilinear. The majority of soils exhibited variable charge characteristics (CEC increases with soil pH) and the curvilinear trend is explained on this basis. At low pH, the difference between pH, and pH measured in an electrolyte will be small compared with the difference at higher pH values because, in general, at low pH, soils will be closer to their respective PZSE (pH at which electrolyte strength has no effect). Of the electrolytes used, pH measured in 0.002 M CaCl2 gave the closest approximation to pHs,. However, when soils with ionic strengths greater than 0.018 M were selected (predominantly cultivated surface soils), pH in 0.01 M CaCl2 gave the best approximation to pHss. For predicting pHss, the ionic strength of the electrolyte will need to be matched to that of the soils studied. For a suite of soils with a large range in soil solution ionic strength (as in this study), it is preferable to measure pHss directly.
6
Kodešová, R. "Miroslav Kutílek – Professor of soil science, soil physics and soil hydrology". Soil and Water Research 3, Special Issue No. 1 (30 giugno 2008): S5—S6. http://dx.doi.org/10.17221/1412-swr.
Testo completo
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Vopravil, J., M. Janeček e M. Tippl. "Revised soil erodibility K-factor for soils in the Czech Republic". Soil and Water Research 2, No. 1 (7 gennaio 2008): 1–9. http://dx.doi.org/10.17221/2100-swr.
Testo completoAbstract (sommario):
In the territory of the Czech Republic there are more than 50% of agricultural soils exposed to water erosion; it is a very urgent problem both at present and for the future. It must be solved now when there is still something to be protected. It is rather complicated to describe the soil properties in terms of soil susceptibility to water erosion because it is a complex relation in which many factors participate. For the complex evaluation of all main factors participating in erosion origination it is possible to apply the Universal Soil Loss Equation (USLE). It consists of six factors interacting with each other and participating in the origination of soil erosion. One of these factors is the soil erodibility factor (K-factor), the revision of which for soil conditions of the CR is the subject of this study. In total ca. 5000 soil pits from the whole territory of the country were processed and evaluated in detail. The main results of this study are K-factor values (means and variances) for the soil types, subtypes and varieties (represented in the database) according to the Taxonomic Classification System of Soils of the Czech Republic.
8
Behrens, T., K. Gregor e W. Diepenbrock. "Separation of soil and canopy reflectance signatures of Mid German agricultural soils". Plant, Soil and Environment 51, No, 7 (19 novembre 2011): 296–303. http://dx.doi.org/10.17221/3589-pse.
Testo completoAbstract (sommario):
Remote sensing can provide visual indications of crop growth during production season. In past, spectral optical estimations were well performed in the ability to be correlated with crop and soil properties but were not consistent within the whole production season. To better quantify vegetation properties gathered via remote sensing, models of soil reflectance under changing moisture conditions are needed. Signatures of reflected radiation were acquired for several Mid German agricultural soils in laboratory and field experiments. Results were evaluated at near-infrared spectral region at the wavelength of 850 nm. The selected soils represented different soil colors and brightness values reflecting a broad range of soil properties. At the wavelength of 850 nm soil reflectance ranged between 10% (black peat) and 74% (white quartz sand). The reflectance of topsoils varied from 21% to 32%. An interrelation was found between soil brightness rating values and spectral optical reflectance values in form of a linear regression. Increases of soil water content from 0% to 25% decreased signatures of soil reflectance at 850 nm of two different soil types about 40%. The interrelation of soil reflectance and soil moisture revealed a non-linear exponential function. Using knowledge of the individual signature of soil reflectance as well as the soil water content at the measurement, soil reflectance could be predicted. As a result, a clear separation is established between soil reflectance and reflectance of the vegetation cover if the vegetation index is known.
9
Gerasimova, М. I., e N. B. Khitrov. "Morphological soil description for classifying soils and interpteting their genesis". Dokuchaev Soil Bulletin 86 (15 dicembre 2016): 8–16. http://dx.doi.org/10.19047/0136-1694-2016-86-8-16.
Testo completo
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Beylich, Anneke, Hans-Rudolf Oberholzer, Stefan Schrader, Heinrich Höper e Berndt-Michael Wilke. "Evaluation of soil compaction effects on soil biota and soil biological processes in soils". Soil and Tillage Research 109, n. 2 (agosto 2010): 133–43. http://dx.doi.org/10.1016/j.still.2010.05.010.
Testo completo
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Nam, Sun-Hwa, e Youn-Joo An. "Review of the Extraction Methods of Soil Extracts, Soil Elutriates, and Soil Suspensions for Ecotoxicity Assessments". Journal of Soil and Groundwater Environment 19, n. 3 (30 giugno 2014): 15–24. http://dx.doi.org/10.7857/jsge.2014.19.3.015.
Testo completo
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Nahirniak, S. V., T. A. Dontsova, A. V. Lapinsky, M. V. Tereshkov e R. C. Singh. "Soil and soil breathing remote monitoring: A short review". Biosystems Diversity 28, n. 4 (14 novembre 2020): 350–56. http://dx.doi.org/10.15421/012044.
Testo completoAbstract (sommario):
The efficiency of agricultural use of soils depends directly on their quality indicators, which include an extended set of characteristics: from data of the environmental situation to the component composition of the soil air. Therefore, for a more complete survey of agricultural land in order to determine their qualitative indicators and subsequent application, it is necessary to carry out comprehensive monitoring while simultaneously studying the characteristics of soils and their air composition. The article is devoted to the literature analysis on the remote monitoring of soils and soil air. Particular attention was paid to the relationship between soil type and soil air composition and it was found that the soil air composition (in the combination with pH and humidity parameters) can assess the type, quality and environmental condition of soils. Since when developing a remote monitoring system of soil air soil moisture and soil structure significantly affect the processes occurring in soils, and ultimately the quantitative composition of soil air, it is very important to know the dependence of the soil air composition on the type and quality of the soil itself, the influence of moisture, structure and other parameters on it. It was shown that the use of sensors is a promising direction for the development of the soils and soil air remote monitoring. It was indicated that soil and soil air remote monitoring in real time will provide reliable, timely information on the environmental status of soils and their quality. Commercial sensors that can be used to determine CO2, O2, NOx, CH4, CO, H2 and NH3 were considered and the technique for sensor signal processing was chosen. A remote monitoring system with the use of existing commercial sensors was proposed, the movement of which can be realized with the help of quadcopter, which will allow parallel scanning of the soils and the land terrain. Such a system will make it possible to correctly assess the readiness of soils for planting, determine their intended use, correctly apply fertilizers, and even predict the yield of certain crops. Thereby, this approach will create a modern on-line system for full monitoring of soil, land and rapid response in the case of its change for the agro-industrial sector.
13
Yu, Dandan, Feilong Hu, Kun Zhang, Li Liu e Danfeng Li. "Available water capacity and organic carbon storage profiles in soils developed from dark brown soil to boggy soil in Changbai Mountains, China". Soil and Water Research 16, No. 1 (11 dicembre 2020): 11–21. http://dx.doi.org/10.17221/150/2019-swr.
Testo completoAbstract (sommario):
The available water capacity (AWC) is the most commonly used parameter for quantifying the amount of soil water that is readily available to plants. Specific AWC and soil organic carbon storage (SOCS) profiles are consequences of the soil development process. Understanding the distributions of AWC and SOCS in soil profiles is crucial for modelling the coupling between carbon and water cycle processes, and for predicting the consequences of global change. In this study, we determined the variations in the AWC and SOCS from the surface to a depth of 100 cm in soils developed from dark brown soil, skeletal dark brown soil, meadow dark brown soil, white starched dark brown soil, meadow soil, and boggy soil in the Changbai Mountains area of China. The AWC and SOCS profiles were calculated for each main soil group/subgroup using only the readily available variables for the soil texture and organic matter with the soil water characteristic equations. The results showed the following. (1) The AWC and SOCS decreased initially and then increased, before decreasing again in soils developed from dark brown soil to boggy soil, where the maximum SOCS occurred in the white starched dark brown soil, and the maximum AWC in the dark brown soil. (2) The SOCS was decreased by deforestation and concomitant soil erosion, but the negative impact of this decrease in the SOCS in the Changbai Mountains area was not caused completely by reductions in AWC. (3) In the soil development process from dark brown soil to boggy soil in response to deforestation, the AWC distribution differed in the profile and even among individual layers, whereas the SOCS was mainly present in the upper layer.
14
Baskoro, Dwi Putro Tejo, e Suria Darma Tarigan. "Soil Moisture Characteristics on Several Soil Types". Jurnal Ilmu Tanah dan Lingkungan 9, n. 2 (1 ottobre 2007): 77–81. http://dx.doi.org/10.29244/jitl.9.2.77-81.
Testo completoAbstract (sommario):
Soil water availability is one of the important factors injluencing plant growth. Soil that can store more water in alonger time can support a better plant growth. This study was aimed to evaluate the dynamics of soil water of four differentsoils with different characteristics. Four soils classes are clayey textured soils-Red Yellowish Podsolik Jasinga, Clayeytextured soils-Latosol Darmaga, . Sandy Textured soil-Regosol Sindang Barang, and highly organic mater content soi/sAndosolSukamantri. The result showed that at every-suction analyzed, Andosol Sukamantri had consistently highest watercontent while Regosol Sindang Barang was consistently lowest. Similar tendency wasfoundfor available water capacity. Theresult also showed that moisture content at Regosol decrease more rapidly than those of the other three soils. The time need to reach likely constant moisture content is variable with soil type; lowest at Regosol Sindangbarang (45 hours after completely saturated and drained) followed by Podsolik Jasinga (73 hours), Latosol darmaga (74 hours) and Andosol Sulcamatri (76 hours).
15
Mad Said, Mohd Jazlan, Adnan Zainorabidin e Aziman Madun. "Soil Velocity Profile on Soft Soil Using Seismic Refraction". Applied Mechanics and Materials 773-774 (luglio 2015): 1549–54. http://dx.doi.org/10.4028/www.scientific.net/amm.773-774.1549.
Testo completoAbstract (sommario):
Soil velocity profile often used as subsurface characterization by using geophysical technic. Seismic refraction is one of geophysical technique to determine primary wave (p-wave) velocity of soil profile. In this paper, seismic refraction technique has been performed on two different types of soft soil (peat soil and RECESS clay) for comparison of its p-wave velocity soil profile. From p-wave velocity soil profile comparison, its show the peat soil has soil velocity range from 211 m/s – 534 m/s at depth of 0 – 4 m while the soft clay show soil velocity range from 248 m/s – 1842 m/s at depth of 0 – 5.5 m. The profiles of peat soils and RECESS clay have been verified using peat samplers and existing borehole data. Both of velocity soil profiles, indicated that peat soil have lower velocity compare with soft clay due to its unique and soft soil characteristics. The difference of p-wave velocity soil profile between peat soil and soft clay are clearly showed both soils have different soil p-wave velocity with different soils characteristics.
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Hussein Razzaq Nayyef. "Effect of continuous cultivation and soil texture on some soil properties". GSC Advanced Research and Reviews 13, n. 1 (30 ottobre 2022): 077–84. http://dx.doi.org/10.30574/gscarr.2022.13.1.0271.
Testo completoAbstract (sommario):
The effects of soil continuous cultivation and soil texture on some of its properties, electrical conductivity, total porosity, and calcium carbonate content and soil penetration resistance. Six samples of soil material for a layer of 0-30 cm were collected from three different texture sites are Clay, Loam and Loamy Sand in Basra Governorate for three sites Abi al-Khasib, Karma and Zubair. Three of these samples represented the treatment of soil continuous cultivation, soil planted with alfalfa crop (Medicago sativa) for 7 consecutive years, and the other three samples from the same sites for uncultivated soil with three replications for each sample. The results showed a decrease in the values of electrical conductivity, calcium carbonate, soil penetration resistance, and an increase in soil porosity values in cultivated soils. The lowest EC values were 4.1, 5.3 and 6.2 dS. m-1 for soils with textures Loamy sand, Loam and Clay, respectively, and for CaCO3 of 182.3 g. kg-1 in Loamy sand, 266.7 g. kg-1 and 310 g. kg-1 for Loam and Clay soils, respectively, and for resistance to penetration of 550 KN.m-1 for clay soils. While it was 620 KN.m-1, and 714 KN.m-1, for loam soil and loamy sand soil, respectively, compared to uncultivated soil. While the soil porosity values increased for cultivated soils compared with uncultivated soils and the values of 43%, 48.53% and 53.4%, for soils with textures Loamy sand, Loam and Clay respectively, And for the average weighted diameter of 0.2537 mm, 0.2817 mm, 0.3640 mm, for soils with textures Loamy sand, Loam and Clay, respectively.
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Liu, Man, e Guilin Han. "Distribution of soil nutrients and erodibility factor under different soil types in an erosion region of Southeast China". PeerJ 9 (16 giugno 2021): e11630. http://dx.doi.org/10.7717/peerj.11630.
Testo completoAbstract (sommario):
Background Soil erosion can affect the distribution of soil nutrients, which restricts soil productivity. However, it is still a challenge to understand the response of soil nutrients to erosion under different soil types. Methods The distribution of soil nutrients, including soil organic carbon (SOC), soil organic nitrogen (SON), and soil major elements (expressed as Al2O3, CaO, Fe2O3, K2O, Na2O, MgO, TiO2, and SiO2), were analyzed in the profiles from yellow soils, red soils, and lateritic red soils in an erosion region of Southeast China. Soil erodibility K factor calculated on the Erosion Productivity Impact Calculator (EPIC) model was used to indicate erosion risk of surface soils (0∼30 cm depth). The relationships between these soil properties were explored by Spearman’s rank correlation analysis, further to determine the factors that affected the distribution of SOC, SON, and soil major elements under different soil types. Results The K factors in the red soils were significantly lower than those in the yellow soils and significantly higher than those in the lateritic red soils. The SON concentrations in the deep layer of the yellow soils were twice larger than those in the red soils and lateritic red soils, while the SOC concentrations between them were not significantly different. The concentrations of most major elements, except Al2O3 and SiO2, in the yellow soils, were significantly larger than those in the red soils and lateritic red soils. Moreover, the concentrations of major metal elements positively correlated with silt proportions and SiO2 concentrations positively correlated with sand proportions at the 0∼80 cm depth in the yellow soils. Soil major elements depended on both soil evolution and soil erosion in the surface layer of yellow soils. In the yellow soils below the 80 cm depth, soil pH positively correlated with K2O, Na2O, and CaO concentrations, while negatively correlated with Fe2O3 concentrations, which was controlled by the processes of soil evolution. The concentrations of soil major elements did not significantly correlate with soil pH or particle distribution in the red soils and lateritic red soils, likely associated with intricate factors. Conclusions These results suggest that soil nutrients and soil erodibility K factor in the yellow soils were higher than those in the lateritic red soils and red soils. The distribution of soil nutrients is controlled by soil erosion and soil evolution in the erosion region of Southeast China.
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Mahdy, A. M. "Comparative effects of different soil amendments on amelioration of saline-sodic soils". Soil and Water Research 6, No. 4 (28 novembre 2011): 205–16. http://dx.doi.org/10.17221/11/2011-swr.
Testo completoAbstract (sommario):
A greenhouse experiment was conducted to test the potential of different soil amendments in saline-sodic soils reclamation; to affect the growth response of alfalfa (Medicago sativa L.) plants grown on two saline-sodic soils; and to evaluate the comparative efficiency of different soil amendments for their effects on salinity, sodicity, and pH levels of the soils. To achieve these objectives, two highly saline-sodic soils were selected (Abees, Typic torrifluvents and Elhammam, Typic calciorthids). Different soil amendments were used (compost, anthracite coal powder, water treatment residuals, ferrous sulphate, and a combination of them). The results of the study indicated that pH of Elhammam soil was less affected than pH of Abees soil after the amendment application because of the high calcium carbonate content which acted as a buffer and resisted any appreciable change in soil pH in the alkaline range. The positive effects of all treatments followed the order: T16 > T12 > T13 > T14 = T5 > T11 = T15 > T7 > T8 > T4 = T6 > T9 = T10 > T2 >T3> T1 >T0. The most effective amendment in reducing SAR<sub>e </sub>in the experimental soils was T16. This was due to the presence of Al in WTRs and Fe in ferrous sulphate which enhanced the leaching process, and the presence of high adsorptive capacity materials like WTRs and compost which adsorb more sodium. The positive effects of all treatments for reducing SAR<sub>e</sub> in Abees soil followed the order: T16 > T15 > T14 > T13 > T11 > T12 .While, in Elhammam soil, the order was: T16 > T15 > T14 > T13 = T11>T12 = T5. The removal sodium efficiency (RSE) or percentage of Na-removed from the soils at the end of the experiment was significantly reduced after the application of the amendments. RSE of T16 proved the highest value (76%) among the treatments for the two soils used, followed by T15 and T14. The yield of biomass at T16 significantly increased, the increase being 959% in comparison with T0 in Abees soil, while the increase in biomass yield was 1452% in comparison with T0 in Elhammam soil. However, field tests are necessary to draw the final conclusions.
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Mátyás, Bence, Maritza Elizabeth Chiluisa Andrade, Nora Carmen Yandun Chida, Carina Maribel Taipe Velasco, Denisse Estefania Gavilanes Morales, Gisella Nicole Miño Montero, Lenin Javier Ramirez Cando e Ronnie Xavier Lizano Acevedo. "Comparing organic versus conventional soil management on soil respiration". F1000Research 7 (2 marzo 2018): 258. http://dx.doi.org/10.12688/f1000research.13852.1.
Testo completoAbstract (sommario):
Soil management has great potential to affect soil respiration. In this study, we investigated the effects of organic versus conventional soil management on soil respiration. We measured the main soil physical-chemical properties from conventional and organic managed soil in Ecuador. Soil respiration was determined using alkaline absorption according to Witkamp. Soil properties such as organic matter, nitrogen, and humidity, were comparable between conventional and organic soils in the present study, and in a further analysis there was no statically significant correlation with soil respiration. Therefore, even though organic farmers tend to apply more organic material to their fields, but this did not result in a significantly higher CO2 production in their soils in the present study.
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Tobiašová, E., G. Barančíková, E. Gömöryová, B. Dębska e M. Banach-Szott. "Humus substances and soil aggregates in the soils with different texture". Soil and Water Research 13, No. 1 (24 gennaio 2018): 44–50. http://dx.doi.org/10.17221/31/2017-swr.
Testo completoAbstract (sommario):
Humus substances (HS) influence the incorporation of carbon into soil aggregates in many ways. In this study the influence of HS and their fractions in the soil on the proportions of carbon (total organic, labile, non-labile) in water-resistant macro-aggregates (WSA) and differences between the amount of carbon in WSA in coarse-grained (CGS) and fine-grained (FGS) soils with dependence on the proportions of HS in the soil were determined. The experiment included three soils (Haplic Chernozem, Haplic Luvisol, Eutric Cambisol), each of them with two different soil textures (CGS, FGS) from four ecosystems (forest, meadow, urban, and agro-ecosystem). In CGS, higher proportions (52 and 50%) of smaller (< 1 mm) dry-sieved macro-aggregates (DSA) and also WSA were determined, while in FGS, higher proportions (51 and 53%) of larger DSA (> 7 mm) and WSA (> 2 mm) were detected. A negative correlation was recorded between the content of organic carbon in the fractions of WSA and the amount of extracted humic acids (HA) in CGS, and fulvic acids (FA) in FGS. In CGS, the correlation between the carbon content in WSA and HA bound with Ca<sup>2+</sup> and Mg<sup>2+</sup>, which forms humates (HA2), was negative. In FGS, a negative correlation was recorded between the carbon content in WSA and free aggressive FA (FA1a) and free FA and those, which are bound with monovalent cations and mobile R<sub>2</sub>O<sub>3</sub> (FA1) in the soil. In the case of FA1a, a negative correlation was recorded in FGS and also in CGS, however this influence was more marked in CGS than in FGS (by about 21% higher correlation). In CGS, the influence of HA and FA in soil on the content of labile carbon in aggregates was stronger than in FGS. In CGS, a higher proportion of carbon in aggregates was detected in the case of lower stability of HS and HA and, on the contrary, in FGS, a higher content of carbon in aggregates was detected in the case of their higher stability.
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Cheng, C., D. Zhao, D. Lv, S. Li e G. Du. "Comparative study on microbial community structure across orchard soil, cropland soil, and unused soil". Soil and Water Research 12, No. 4 (9 ottobre 2017): 237–45. http://dx.doi.org/10.17221/177/2016-swr.
Testo completoAbstract (sommario):
We examined the effects of three different soil conditions (orchard soil, cropland soil, unused soil) on the functional diversity of soil microbial communities. The results first showed that orchard and cropland land use significantly changed the distribution and diversity of soil microbes, particularly at surface soil layers. The richness index (S) and Shannon diversity index (H) of orchard soil microbes were significantly higher than the indices of the cropland and unused soil treatments in the 0–10 cm soil layer, while the S and H indices of cropland soil microbes were the highest in 10–20 cm soil layers. Additionally, the Simpson dominance index of cropland soil microbial communities was the highest across all soil layers. Next, we found that carbon source differences in soil layers under the three land use conditions can mainly be attributed to their carbohydrate and polymer composition, indicating that they are the primary cause of the functional differences in microbial communities under different land uses. In conclusion, orchard and cropland soil probably affected microbial distribution and functional diversity due to differences in vegetation cover, cultivation, and management measures.
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McKEAGUE, J. A., e G. C. TOPP. "PITFALLS IN INTERPRETATION OF SOIL DRAINAGE FROM SOIL SURVEY INFORMATION". Canadian Journal of Soil Science 66, n. 1 (1 febbraio 1986): 37–44. http://dx.doi.org/10.4141/cjss86-004.
Testo completoAbstract (sommario):
Soil drainage groups assigned on the basis of soil survey information were evaluated against measured saturated hydraulic conductivity (Ksat) data for nine soils in Ontario. The drainage groups used in the drainage guide for Ontario, are based mainly on assumed relationships between soil texture and the capacity of the soil to transmit water.Measured Ksat values were incompatible with the drainage groups assigned to at least four of the nine soils. For the soils tested, there was very little relationship between texture and Ksat. Structure, including porosity, had a major influence on Ksat, and near-surface structure is influenced greatly by land use. Thus, general interpretations of the drainage characteristics of soil series have serious limitations. The usefulness of soil survey information for interpretation of soil drainage could be increased by improved description of soil morphology and by reliable estimates of Ksat during mapping. Such estimates can be based on morphology if they are regularly recalibrated by measurement. Key words: Hydraulic conductivity, tile drainage, texture, soil morphology
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McCracken, Ralph J. "Soils, Soil Scientists, and Civilization". Soil Science Society of America Journal 51, n. 6 (novembre 1987): 1395–400. http://dx.doi.org/10.2136/sssaj1987.03615995005100060001x.
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Koyluoglu, U. "Soil mechanics for unsaturated soils". Soil Dynamics and Earthquake Engineering 12, n. 7 (1993): 449–50. http://dx.doi.org/10.1016/0267-7261(93)90011-f.
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Bertsch, Floria. "Soil fertility of tropical soils". Soil and Tillage Research 37, n. 2-3 (giugno 1996): 208–9. http://dx.doi.org/10.1016/0167-1987(96)85125-7.
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Hong, Shan, Hongling Jv, Xianfu Yuan, Jianjian Geng, Beibei Wang, Yan Zhao, Qing Wang, Rong Li, Zhongjun Jia e Yunze Ruan. "Soil Organic Nitrogen Indirectly Enhances Pepper-Residue-Mediated Soil Disease Suppression through Manipulation of Soil Microbiome". Agronomy 12, n. 9 (31 agosto 2022): 2077. http://dx.doi.org/10.3390/agronomy12092077.
Testo completoAbstract (sommario):
Banana Fusarium wilt-suppressive soils are effective against pathogen invasion, yet soil physicochemical factors responsible for conducive or suppressive behavior have not been reported. Here, we investigated the changes in banana biomass, disease incidence (DI), soil culturable microbes and physicochemical properties by incorporating pepper and banana residues into conducive and suppressive soils. Before the incorporation of any residues, the suppressive soil significantly increased banana biomass and decreased DI compared to the conducive soil. The biomass of the suppressive soil was significantly higher than that of the conducive soil after the incorporation of either pepper or banana residues. Compared with the control (CK), the incorporation of pepper residues to both soils significantly reduced DI, while banana residues had the opposite effect. Additionally, both conducive and suppressive soils supplemented with pepper residues significantly reduced the amounts of culturable Fusarium oxysporum and increased the amounts of beneficial Pseudomonas and Bacillus. The pepper residue extracts significantly inhibited the growth of F. oxysporum mycelium. Soil alkali-hydrolyzable nitrogen (AN) responded most strongly to residue application to suppressive soil. The AN factor was significantly and positively correlated with banana biomass; however, there was no direct and significant negative correlation with DI. Further analysis of the results showed that elevated AN content could stimulate the amounts of culturable Bacillus in the soil, and Bacillus antagonized the proliferation of pathogen and thus indirectly and effectively reduced banana DI. In conclusion, soil AN content can indirectly improve the disease suppression ability of pepper-residue-mediated suppressive soil by manipulating the soil microbiome.
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Simakova, M., D. Rukhovitch, E. Vilchevskaya, N. Kalinina, L. Kolesnikova e P. Koroleva. "CONTENT ADDITION TO THE STATE SOIL MAP WITH GENESIS INFORMATION OF SOIL PARENT MATERIALS AND GRANULOMETRIC COMPOSITION OF SOIL". Dokuchaev Soil Bulletin, n. 66 (11 dicembre 2010): 3–16. http://dx.doi.org/10.19047/0136-1694-2010-66-3-16.
Testo completoAbstract (sommario):
The substantiation of the first stage of works with the digital version of the State Soil Map (SSC) on elimination of differences on different sheets in the representation of genesis of soil-forming rocks, granulometric composition of soils and rocks is given. The content and characteristics of cartographic and literary sources containing information on the genesis of soil-forming rocks. Necessity of separate showing of granulometric composition of soil-forming rocks and soils on HCC is justified. Granulometric composition of soils on GPC is shown in the C horizon, which is a characteristic of deposits on which soils are formed. Granulometric composition of soils at description on of other maps is characterized by the upper horizons. On the example of specific analytical data of soils with differentiated granulometric composition of the profile shows ways to solve the problem.Granulometric composition of soils with undifferentiated granulometric composition of the profile is identical to that of soil-forming factors.
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Balkovič, J., Z. Rašeková, V. Hutár, J. Sobocká e R. Skalský. "Digital soil mapping from conventional field soil observations". Soil and Water Research 8, No. 1 (6 febbraio 2013): 13–25. http://dx.doi.org/10.17221/43/2012-swr.
Testo completoAbstract (sommario):
We tested the performance of a formalized digital soil mapping (DSM) approach comprising fuzzy k-means (FKM) classification and regression-kriging to produce soil type maps from a fine-scale soil observation network in Rišňovce, Slovakia. We examine whether the soil profile descriptions collected merely by field methods fit into the statistical DSM tools and if they provide pedologically meaningful results for an erosion-affected area. Soil texture, colour, carbonates, stoniness and genetic qualifiers were estimated for a total of 111 soil profiles using conventional field methods. The data were digitized along semi-quantitative scales in 10-cm depth intervals to express the relative differences, and afterwards classified by the FKM method into four classes A–D: (i) Luvic Phaeozems (Anthric), (ii) Haplic Phaeozems (Anthric, Calcaric, Pachic), (iii) Calcic Cutanic Luvisols, and (iv) Haplic Regosols (Calcaric). To parameterize regression-kriging, membership values (MVs) to the above A–D class centroids were regressed against PCA-transformed terrain variables using the multiple linear regression method (MLR). MLR yielded significant relationships with R<sup>2</sup> ranging from 23% to 47% (P < 0.001) for classes A, B and D, but only marginally significant for Luvisols of class C (R<sup>2</sup> = 14%, P < 0.05). Given the results, Luvisols were then mapped by ordinary kriging and the rest by regression-kriging. A “leave-one-out” cross-validation was calculated for the output maps yielding R<sup>2</sup> of 33%, 56%, 22% and 42% for Luvic Phaeozems, Haplic Phaeozems, Luvisols and also Regosols, respectively (all P < 0.001). Additionally, the pixel-mixture visualization technique was used to draw a synthetic digital soil map. We conclude that the DSM model represents a fully formalized alternative to classical soil mapping at very fine scales, even when soil profile descriptions were collected merely by field estimation methods. Additionally to conventional soil maps it allows to address the diffuse character in soil cover, both in taxonomic and geographical interpretations.
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Kotorová, Dana, Jana Jakubová e Ladislav Kováč. "Dependence of Heavy Soil Transport Function on Soil Profile Depth". Agriculture (Polnohospodárstvo) 57, n. 2 (1 giugno 2011): 45–52. http://dx.doi.org/10.2478/v10207-011-0005-0.
Testo completoAbstract (sommario):
Dependence of Heavy Soil Transport Function on Soil Profile DepthThe aim of this work was to quantify the effect of soil profile depth on the transport function of heavy soils. Treatments were carried out between 2006 and 2009 in Milhostov. Two variants were examined : the (conventional soil tillage and long-time no-tilled variant). Soil samples were taken in spring and autumn from soil profile depth of 0.00-0.60 m from each 0.10 m. For further evaluation the average values were used. Particle size composition, bulk density, total porosity and maximum capillary capacity were determined. Content of clay particles in soil profile was in interval 59.64-68.53% and such soils are characterised in the range from clay-loamy soil to clayey soil. The bulk density increased with the depth of soil profile and its values reached 1 184-1 646 kg m-3. The total porosity was in range 37.68-55.17% and it decreased with the depth of soil profile. The values of maximum capillary capacity were characterised for heavy soils with high content of clay particles. The depth had statistically significant effect on all observed parameters. In average, on both variants the bulk density was higher than 1 400 kg m-3, the total porosity was lower than 47% and the content of clay was higher than 30%, pointing to the possibility of soil compaction, which will result in reduced transport function of heavy soils.
30
Liu, J., C. Geng, Y. Mu, Y. Zhang e H. Wu. "Exchange of carbonyl sulfide (COS) between the atmosphere and various soils in China". Biogeosciences Discussions 6, n. 6 (12 novembre 2009): 10557–82. http://dx.doi.org/10.5194/bgd-6-10557-2009.
Testo completoAbstract (sommario):
Abstract. Using a dynamic enclosure, the exchange fluxes of carbonyl sulfide (COS) between the atmosphere and 18 soils from 10 provinces in China were investigated. The emission or uptake of COS from the soils was highly dependent on the soil type, soil temperature, soil moisture, and atmospheric COS mixing ratio. In general, with the only exception being paddy soils, the soils in this investigation acted as sinks for atmospheric COS under wide ranges of soil temperature and soil moisture. Two intensively investigated wheat soils and one forest soil, had optimal soil temperatures for COS uptake of around 15°C, and the optimal soil water content varied from 13 to 58%. The two paddy soils, exponentially COS emission fluxes increased with increasing soil temperature, and decreased COS emission fluxes with increased soil water content. However, negligible emission was found when the paddy soils were under waterlogging status. The observed compensation points for various soils were different and increased significantly with soil temperature. The laboratory simulation agreed with the preliminary field measurements for the paddy soil in Jiaxing, Zhejiang province.
31
Liu, J., C. Geng, Y. Mu, Y. Zhang, Z. Xu e H. Wu. "Exchange of carbonyl sulfide (COS) between the atmosphere and various soils in China". Biogeosciences 7, n. 2 (25 febbraio 2010): 753–62. http://dx.doi.org/10.5194/bg-7-753-2010.
Testo completoAbstract (sommario):
Abstract. Using a dynamic enclosure, the exchange rates of carbonyl sulfide (COS) between the atmosphere and 18 soils from 12 provinces in China were investigated. The emission or uptake of COS from the soils was highly dependent on the soil type, soil temperature, soil moisture, and atmospheric COS mixing ratio. In general, with the only exception being paddy soils, the soils in this investigation acted as sinks for atmospheric COS under wide ranges of soil temperature and soil moisture. Two intensively investigated wheat soils and one forest soil had optimal soil temperatures for COS uptake of around 15 °C, and the optimal soil water content varied from 13% to 58%. COS emission rates from the two paddy soils increased exponentially with increment of the soil temperature, and decreased with increasing the soil water content. However, negligible emission was found when the paddy soils were under waterlogging status. The observed compensation points for various soils were different and increased significantly with soil temperature. The laboratory simulation agreed with the preliminary field measurements for the paddy soil in Jiaxing, Zhejiang province.
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Taraqqi-A-Kamal, A., Christopher J. Atkinson, Aimal Khan, Kaikai Zhang, Peng Sun, Sharmin Akther e Yanrong Zhang. "Biochar remediation of soil: linking biochar production with function in heavy metal contaminated soils". Plant, Soil and Environment 67, No. 4 (30 marzo 2021): 183–201. http://dx.doi.org/10.17221/544/2020-pse.
Testo completoAbstract (sommario):
The focus of this study is on the soil physicochemical, biological, and microbiological processes altered by biochar application to heavy metal (HM) contaminated soils. The aim is to highlight agronomical and environmental issues by which the restorative capacity of biochar might be developed. Literature shows biochar can induce soil remediation, however, it is unclear how soil processes are linked mechanistically to biochar production and if these processes can be manipulated to enhance soil remediation. The literature often fails to contribute to an improved understanding of the mechanisms by which biochar alters soil function. It is clear that factors such as biochar feedstock, pyrolysis conditions, application rate, and soil type are determinants in biochar soil functionality. These factors are developed to enhance our insight into production routes and the benefits of biochar in HM soil remediation. Despite a large number of studies of biochar in soils, there is little understanding of long-term effects, this is particularly true with respect to the use and need for reapplication in soil remediation.
33
Sofo, Adriano, Alba Nicoletta Mininni e Patrizia Ricciuti. "Soil Macrofauna: A key Factor for Increasing Soil Fertility and Promoting Sustainable Soil Use in Fruit Orchard Agrosystems". Agronomy 10, n. 4 (25 marzo 2020): 456. http://dx.doi.org/10.3390/agronomy10040456.
Testo completoAbstract (sommario):
Soils and crops in orchard agrosystems are particularly vulnerable to climate change and environmental stresses. In many orchard soils, soil biodiversity and the ecosystem services it provides are under threat from a range of natural and manmade drivers. In this scenario, sustainable soil use aimed at increasing soil organic matter (SOM) and SOM-related benefits, in terms of soil quality and fertility, plays a crucial role. The role of soil macrofaunal organisms as colonizers, comminutors and engineers within soils, together with their interactions with microorganisms, can contribute to the long-term sustainability of orchard soils. Indeed, the continuous physical and chemical action of soil fauna significantly affects SOM levels. This review paper is focused on the most advanced and updated research on this argument. The analysis of the literature highlighted that a significant part of soil quality and fertility in sustainably-managed fruit orchard agrosystems is due to the action of soil macrofauna, together with its interaction with decomposing microorganisms. From the general analysis of the data obtained, it emerged that the role of soil macrofauna in orchards agrosystems should be seriously taken into account in land management strategies, focusing not exclusively on fruit yield and quality, but also on soil fertility restoration.
34
Kallenbach, Cynthia M., Richard T. Conant, Francisco Calderón e Matthew D. Wallenstein. "A novel soil amendment for enhancing soil moisture retention and soil carbon in drought-prone soils". Geoderma 337 (marzo 2019): 256–65. http://dx.doi.org/10.1016/j.geoderma.2018.09.027.
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Donerian, Larisa G., M. A. Vodianova e Zh E. Tarasova. "Microscopic soil fungi - bioindicators organisms contaminated soil". Hygiene and sanitation 95, n. 9 (28 ottobre 2019): 891–94. http://dx.doi.org/10.18821/0016-9900-2016-95-9-891-894.
Testo completoAbstract (sommario):
In the paper there are considered methodological issues for the evaluation of soil biota in terms of oil pollution. Experimental studies have shown that under the exposure of a various levels of oil pollution meeting certain gradations of the state and optimal alteration in microbocenosis in sod-podzolic soils, there is occurred a transformation of structure of the complex of micromycetes and the accumulation of toxic species, hardly typical for podzolic soils - primarily represantatives of the genus Aspergillus (A.niger and A. versicolor), Paecilomyces (P.variotii Bainer), Trichoderma (T.hamatum), the genus of phytopathogens Fusarium (F.oxysporum), dermatophytes of genus Sporothrix (S. schenckii) and dark-colored melanin containing fungi of Dematiaceae family. Besides that there are presented data on the study of microbiocenosis of the urban soil, the urban soil differed from the zone soil, but shaped in similar landscape and climatic conditions, and therefore having a tendency to a similar response from the side of microorganisms inhabiting the soil. Isolated complex of soil microscopic fungi is described by many authors as a complex, characteristic for soils of megalopolises. This allowed authors of this work to suggest that in urban soils the gain in the occurrence of pathogenic species micromycetes also increases against a background of chronic, continuously renewed inflow of petroleum hydrocarbons from various sources of pollution. Because changes in the species composition of micromycetes occurred in accordance with the increasing load of oil, so far as microscopic soil fungi can be recommended as a bioindicator organisms for oil. In the article there is also provided information about the distinctive features of modern DNA identification method of soil microscopic fungi and accepted in our country methodology of isolation of micromycetes with the use of a nutrient Czapek medium.
36
Hart, M. R., e P. S. Cornish. "Soil Sample Depth in Pasture Soils for Environmental Soil Phosphorus Testing". Communications in Soil Science and Plant Analysis 42, n. 1 (7 dicembre 2010): 100–110. http://dx.doi.org/10.1080/00103624.2011.528492.
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Meulemans, Germain, Marine Legrand, Anaïs Tondeur, Yesenia Thibault-Picazo e Alan Vergnes. "Soil Fictions: Addressing Urban Soils between Art, Soil Ecology, and Anthropology". Collaborative Anthropologies 10, n. 1-2 (2017): 20–44. http://dx.doi.org/10.1353/cla.2017.0001.
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38
Smiles, DE. "Soil Science, soil protection and productivity opening address - National soils conference". Soil Research 30, n. 6 (1992): 817. http://dx.doi.org/10.1071/sr9920817.
Testo completoAbstract (sommario):
Australia will continue to rely on its soils to maintain national well being. At the same time society will be more demanding that the soil resource be managed sustainably. Soil scientists are therefore challenged to be more effective in helping formulate policy, contributing to public understanding and in applying their knowledge to meet national need. Close consultation with land managers to define important problems is necessary as is increasing confidence that the knowledge we have is appropriate to the task. It is also important to recognise that much of our science was generated as a reductionist response to difficult problems and it is now necessary to integrate our knowledge to deal with those problems. Collaboration across organisations to ensure most effective use of that knowledge is necessary. Important opportunities to demonstrate application of soil science are identified. A plea is made to teach the subject, not just as an intellectual exercise but as a basis for problem solving across the whole range of uses to which soils are put. Case studies for guidance and to identify knowledge gaps are sought. There is also need to recognise that different client industries demand different communication models to ensure that soil science knowledge is applied appropriately.
39
Fiedler, Sabine, e Reinhold Jahn. "Accumulation soils like “Ockererde”—forgotten soil units in soil-classification systems". Journal of Plant Nutrition and Soil Science 168, n. 6 (dicembre 2005): 741–48. http://dx.doi.org/10.1002/jpln.200521824.
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Vopravil, Jan, Pavel Formánek e Tomáš Khel. "Comparison of the physical properties of soils belonging to different reference soil groups". Soil and Water Research 16, No. 1 (11 dicembre 2020): 29–38. http://dx.doi.org/10.17221/31/2020-swr.
Testo completoAbstract (sommario):
Soil properties can be influenced by long-term agricultural management practices as described in pedological literature. In this study, selected physical properties (particle density and bulk density, total porosity, maximum capillary water capacity, minimum air capacity, field capacity, permanent wilting point and available water capacity) of topsoils from different reference soil groups (Cambisols, Luvisols, Fluvisols, Chernozems and Phaeozems, Leptosols, Stagnosols and Gleysols) were sampled and analysed in the years 2016–2017. The topsoil samples were taken from points of so-called S (specific) soil pits to be sampled from the General Soil Survey of Agricultural Soils (GSSAS) which was accomplished in the years 1961–1970. In addition, some of the properties were also compared with those measured during the GSSAS. Recognising the properties, only the particle density, the maximum capillary water capacity, the permanent wilting point and the available water capacity of the topsoil of the individual soil groups were statistically significantly (P < 0.05) different. A comparison of the physical properties with those analysed after more than 40 years was performed, the bulk density increased and the total porosity decreased in the topsoil of the major part of the studied soil groups.
41
He, Shi, Xinbao Yu, Aritra Banerjee e Anand J. Puppala. "Expansive Soil Treatment with Liquid Ionic Soil Stabilizer". Transportation Research Record: Journal of the Transportation Research Board 2672, n. 52 (23 agosto 2018): 185–94. http://dx.doi.org/10.1177/0361198118792996.
Testo completoAbstract (sommario):
Calcium-based stabilizers such as lime and cement control swell and shrinkage behavior and enhance strength properties for expansive soils through the formation of pozzolanic components. However, sulfate-bearing subgrade soils stabilized with calcium-based stabilizers might cause excessive swelling and shrinkage due to the formation of highly expansive minerals like ettringite and thaumasite. In this paper, one liquid ionic soil stabilizer (LISS) was evaluated as an alternative stabilizer used to control swelling and shrinkage behavior of expansive soils. A comprehensive laboratory experiment program including a linear shrinkage test, a one-dimensional swell test, and an unconfined compressive strength test, was designed and carried out on soils from Dallas, Texas before and after treatment. Three dosage levels of stabilizer and four different curing periods were investigated. Test results indicate that LISS is an effective stabilizing agent, which not only reduces swelling and soil plasticity but also increases soil strength. Furthermore, a similar type of LISS is utilized to treat the soil in Dallas via deep injection using a hydraulic pump. Field emission scanning electron microscopy results on the test soil showed that the stabilizing program is likely to work through clay flocculation and morphological variations in the clay particles.
42
Wang, Jian, Dexter B. Watts, Qinqian Meng, Fan Ma, Qingfeng Zhang, Penghui Zhang e Thomas R. Way. "Influence of Soil Wetting and Drying Cycles on Soil Detachment". AgriEngineering 4, n. 2 (16 giugno 2022): 533–43. http://dx.doi.org/10.3390/agriengineering4020036.
Testo completoAbstract (sommario):
Agricultural soils undergo periods of saturation followed by desiccation throughout the course of a growing season. It is believed that these periods of wetting and drying influence soil structure and may affect the rate of soil detachment. Thus, an experiment was conducted to investigate the influence of a disturbed soil (soil sieved to simulate tillage) subjected to various wetting and drying cycles, on soil bulk density and the resistance to soil detachment with runoff. Seven treatments consisting of wetting and drying cycles ranging from 0 to 6 cycles were evaluated under laboratory conditions using an experimental flume apparatus. A Richards growth model proposed for predicting the influence of wetting and drying on soil detachment was also evaluated. Results showed that the soil bulk density increased as the number of wetting and drying cycles increased. The soil detachment rate decreased as the number of wetting and drying cycles increased. Moreover, initial soil detachment (occurring as soon as runoff began) rates were high for 1 to 3 wetting and drying cycles, while the rate of initial detachment decreased after the third cycle. For example, soils with two and three wetting and drying cycles took 6.5 and 7 min to reach the maximum 1 cm souring depth, respectively, while the soils subjected to four or more wetting and drying cycles did not reach the maximum 1 cm depth during the 15 min runoff experiment. In addition, the proposed S-Shaped Richards growth model was a good predictor for estimating the soil detachment of soils experiencing various wetting and drying cycles. Findings from this study suggest that more attention should be given to the influence that soil wetting and drying have on the prediction of soil detachment. Information from this study is expected to be useful for improving soil management strategies for reducing soil erosion.
43
Eckertová, Terézia, Karol Holý, Monika Müllerová, Ivan Sýkora e Jozef Masarik. "EMANATION OF RADON-222 FROM DIFFERENT SOIL TYPES AND SOIL GROUPS". Radiation Protection Dosimetry 198, n. 9-11 (agosto 2022): 771–77. http://dx.doi.org/10.1093/rpd/ncac132.
Testo completoAbstract (sommario):
Abstract In this paper, we deal with measurement of 222Rn emanation coefficient (Ke) of soils using an accumulation method. We created a database of Ke values of dried soils for various soil types and soil groups, classified by the size of soil particles. For 18 different soil samples we obtained the Ke values in range 0.083–0.234. The analysis of radon emanation dependence on moisture for seven of these samples shows two different trends which were related to soil texture (clays or sands). Soils with predominant sandy particles prove weak dependence on moisture and Ke values from minimum value (at zero moisture) do not increase much (max 15% increase on every 5% of moisture), for soils with majority of clayey particles the moisture can affect the Ke more significantly (increase up to 60%).
44
Okalebo, Jane, Gary Y. Yuen, Rhae A. Drijber, Erin E. Blankenship, Cafer Eken e John L. Lindquist. "Biological Suppression of Velvetleaf (Abutilon theophrasti) in an Eastern Nebraska Soil". Weed Science 59, n. 2 (giugno 2011): 155–61. http://dx.doi.org/10.1614/ws-d-10-00115.1.
Testo completoAbstract (sommario):
Weed-suppressive soils contain naturally occurring microorganisms that suppress a weed by inhibiting its growth, development, and reproductive potential. Increased knowledge of microbe–weed interactions in such soils could lead to the identification of management practices that create or enhance soil suppressiveness to weeds. Velvetleaf death and growth suppression was observed in a research field (fieldA) that was planted with high populations of velvetleaf, which may have developed via microbial mediated plant–soil feedback. Greenhouse studies were conducted with soil collected fromfieldA(soilA) to determine if it was biologically suppressive to velvetleaf. In one study, mortality of velvetleaf grown for 8 wk insoilAwas greatest (86%) and biomass was smallest (0.3 g plant−1) in comparison to soils collected from surrounding fields with similar structure and nutrient content, indicating that suppressiveness ofsoilAwas not likely caused by physical or chemical factors. WhensoilAwas autoclaved in another study, mortality of velvetleaf plants in the heat-treated soil was reduced to 4% compared to 55% for the untreated soil, thus suggesting that suppressiveness ofsoilAis biological in nature. A third set of experiments showed that suppressiveness to velvetleaf could be transferred to an autoclaved soil by amending the autoclaved soil with untreatedsoilA; this provided additional evidence for a biological basis for the effects ofsoilA.The suppressive condition in these greenhouse experiments was associated with high soil populations of fusaria.Fusarium lateritiumwas the most frequently isolated fungus from roots of diseased velvetleaf plants collected fromfieldA, and also was the most virulent when inoculated onto velvetleaf seedlings. Results of this research indicate that velvetleaf suppression can occur naturally in the field and thatF. lateritiumis an important cause of velvetleaf mortality infieldA.
45
Sierra, C. A., M. Müller e S. E. Trumbore. "Modeling radiocarbon dynamics in soils: SoilR version 1.1". Geoscientific Model Development 7, n. 5 (3 settembre 2014): 1919–31. http://dx.doi.org/10.5194/gmd-7-1919-2014.
Testo completoAbstract (sommario):
Abstract. Radiocarbon is an important tracer of the global carbon cycle that helps to understand carbon dynamics in soils. It is useful to estimate rates of organic matter cycling as well as the mean residence or transit time of carbon in soils. We included a set of functions to model the fate of radiocarbon in soil organic matter within the SoilR package for the R environment for computing. Here we present the main system equations and functions to calculate the transfer and release of radiocarbon from different soil organic matter pools. Similarly, we present functions to calculate the mean transit time for different pools and the entire soil system. This new version of SoilR also includes a group of data sets describing the amount of radiocarbon in the atmosphere over time, data necessary to estimate the incorporation of radiocarbon in soils. Also, we present examples on how to obtain parameters of pool-based models from radiocarbon data using inverse parameter estimation. This implementation is general enough so it can also be used to trace the incorporation of radiocarbon in other natural systems that can be represented as linear dynamical systems.
46
Sierra, C. A., M. Müller e S. E. Trumbore. "Modeling radiocarbon dynamics in soils: SoilR version 1.1". Geoscientific Model Development Discussions 7, n. 3 (7 maggio 2014): 3161–92. http://dx.doi.org/10.5194/gmdd-7-3161-2014.
Testo completoAbstract (sommario):
Abstract. Radiocarbon is an important tracer of the global carbon cycle that helps to understand carbon dynamics in soils. It is useful to estimate rates of organic matter cycling as well as the mean residence or transit time of carbon in soils. We included a set of functions to model the fate of radiocarbon in soil organic matter within the SoilR package for the R environment for computing. Here we present the main system equations and functions to calculate the transfer and release of radiocarbon from different soil organic matter pools. Similarly, we present functions to calculate the mean transit time for different pools and the entire soil system. This new version of SoilR also includes a group of datasets describing the amount of radiocarbon in the atmosphere over time, data necessary to estimate the incorporation of radiocarbon in soils. Also, we present examples on how to obtain parameters of pool-based models from radiocarbon data using inverse parameter estimation. This implementation is general enough so it can also be used to trace the incorporation of radiocarbon in other natural systems that can be represented as linear dynamical systems.
47
Wang, Yang, Ronald Amundson e Susan Trumbore. "Radiocarbon Dating of Soil Organic Matter". Quaternary Research 45, n. 3 (maggio 1996): 282–88. http://dx.doi.org/10.1006/qres.1996.0029.
Testo completoAbstract (sommario):
AbstractRadiocarbon ages of soil organic matter are evaluated with a model which incorporates the dynamics of the 14C content of soil organic matter. Measured 14C ages of soil organic matter or its fractions are always younger than the true ages of soils due to continuous input of organic matter into soils. Differences in soil C dynamics due to climate or soil depth will result in significantly different 14C signatures of soil organic matter for soils of the same age. As a result, the deviation of the measured 14C age from the true age of soil formation could differ significantly among different soils or soil horizons. Our model calculations also suggest that 14C ages of soil organic matter will eventually reach a steady state provided that no climatic or ecological perturbations occur. Once a soil or a soil horizon has reached a steady state, 14C dating of soil organic matter will provide no useful information regarding the age of the soil. However, for soils in which steady state has not been reached, it is possible to estimate the age of soil formation by modeling the measured 14C contents of soil organic matter. Radiocarbon dating of buried soils could, in general, overestimate the true age of the burial by as much as the steady-state age of the soil or soil horizon.
48
Liu, Yufei, Xiaoxu Fan, Tong Zhang, Xin Sui e Fuqiang Song. "Effects of atrazine application on soil aggregates, soil organic carbon and glomalin-related soil protein". Plant, Soil and Environment 67, No. 3 (1 marzo 2021): 173–81. http://dx.doi.org/10.17221/594/2020-pse.
Testo completoAbstract (sommario):
Atrazine is still widely used in China. Atrazine residue (1.86–1 100 mg/kg) in the soil has exceeded the allowable limit (1.0 mg/kg), affecting soil structure and soil aggregate composition. To understand the long-term application of atrazine on soil aggregates and the binding agent, four treatments were established in cornfield planted since 1998, including without atrazine applied (AT<sub>0</sub>), atrazine applied (28% atrazine, 1 200–1 350 mL/ha/year) once a year from 2012 to 2018 (AT<sub>6</sub>, 167 mg/kg), from 2008 to 2018 (AT<sub>10</sub>, 127.64 mg/kg) as well as from 2002 to 2018 (AT<sub>16</sub>, 102 mg/kg) with three replications. Along with the increase of atrazine application time, the mass fraction of soil aggregates > 5 mm and 2–5 mm decreased significantly while the mass fraction of soil aggregates 0.5–2 mm and < 0.5 mm increased gradually, and the change of aggregate binding agents contents were the same as that of aggregates. The contents of soil organic carbon (SOC) and glomalin-related soil protein (GRSP) in the aggregates > 5 mm and 2–5 mm were significantly negatively correlated with the years of atrazine application. Our results show that although atrazine residue in the soil does not increase with the increased yearly application, its concentration is still markedly higher than the permitted limit value and seriously affected the content of SOC and GRSP of aggregates > 2 mm, which can lead to a decrease of soil aggregate stability and soil quality.
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Gömöryová, Erika, Gabriela Barančíková, Erika Tobiašová, Ján Halás, Rastislav Skalský, Štefan Koco e Dušan Gömöry. "Responses of soil microorganisms to land use in different soil types along the soil profiles". Soil and Water Research 15, No. 2 (11 marzo 2020): 125–34. http://dx.doi.org/10.17221/20/2019-swr.
Testo completoAbstract (sommario):
The objective of this study was to find out how land use affects the soil microbial attributes in different soil types and to which depth. The study was performed in Slovakia (Europe) in three areas differing in soil type (Chernozem, Stagnosol, Cambisol). Within each area, three localities with different land use (forest, grassland, cropland), representing a gradient with different intensity of management, were chosen. The soil samples were taken along a single soil profile up to a depth of 1 m with 10 cm increments at each locality. In the soil samples, the basic soil chemical properties and microbial attributes were determined. The effect of the land use on the microbial biomass and basal respiration was mainly observed in the Chernozem in the top 30 cm, while in the Stagnosol, no difference in the trend in the microbial biomass between the different ecosystems along the soil profile was found. The N-mineralisation reflected the different management practices especially in the Cambisol in the top 20 cm. The most distinct differences in the catalase activity between the soils differing in land use were found in the Cambisol along the whole profile. The richness and diversity of the functional groups did not differ significantly between the soils with the different land use and also no uniform responses of the functional groups composition to the land use were observed. The microbial biomass and activity were mainly affected by the amount of the soil organic matter; the intensity of the impact differed according to the soil type.
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Hatano, Ryusuke, Ikabongo Mukumbuta e Mariko Shimizu. "Soil Health Intensification through Strengthening Soil Structure Improves Soil Carbon Sequestration". Agriculture 14, n. 8 (5 agosto 2024): 1290. http://dx.doi.org/10.3390/agriculture14081290.
Testo completoAbstract (sommario):
Intensifying soil health means managing soils to enable sustainable crop production and improved environmental impact. This paper discusses soil health intensification by reviewing studies on the relationship between soil structure, soil organic matter (SOM), and ecosystem carbon budget. SOM is strongly involved in the development of soil structure, nutrient and water supply power, and acid buffering power, and is the most fundamental parameter for testing soil health. At the same time, SOM can be both a source and a sink for atmospheric carbon. A comparison of the ratio of soil organic carbon to clay content (SOC/Clay) is used as an indicator of soil structure status for soil health, and it has shown significantly lower values in cropland than in grassland and forest soils. This clearly shows that depletion of SOM leads to degradation of soil structure status. On the other hand, improving soil structure can lead to increasing soil carbon sequestration. Promoting soil carbon sequestration means making the net ecosystem carbon balance (NECB) positive. Furthermore, to mitigate climate change, it is necessary to aim for carbon sequestration that can improve the net greenhouse gas balance (NGB) by serving as a sink for greenhouse gases (GHG). The results of a manure application test in four managed grasslands on Andosols in Japan showed that it was necessary to apply more than 2.5 tC ha−1 y−1 of manure to avoid reduction and loss of SOC in the field. Furthermore, in order to offset the increase in GHG emissions due to N2O emissions from increased manure nitrogen input, it was necessary to apply more than 3.5 tC ha−1y−1 of manure. To intensify soil health, it is increasingly important to consider soil management with organic fertilizers that reduce chemical fertilizers without reducing yields.