scholarly journals Measuring and Estimating Pressure-Saturation Curves on Undisturbed Soil Samples by Using Water and NAPL

2002 ◽  
Vol 51 (1-2) ◽  
pp. 27-36 ◽  
Author(s):  
Csaba Makó

In order to expand the experimental data set of models describing the movement of organic liquids polluting the soils, a series of experiments was set up in which the fluid retention (pressure- s aturation curves of the soils) were measured using water and NAPL (DUNASOL 180/220, a non aromatic petroleum product). Measurements were carried out on undisturbed soil samples originating from 35 different horizons of 12 characteristic Hungarian soils. The P-S curves with NAPL were determined in series, by a modified pressure cell apparatus - designed and constructed in the laboratory of our department - containing oil-resistant (silicon rubber, Teflon) components.   The applied methodology and the statistical analysis of the measured data are presented. The results show that the commonly used Leverett-type scaling of the water retention data provides inadequate estimation of the NAPL retention in some cases. This deviation may be a direct result of changes in clay volume and soil aggregation when saturation with different fluids was performed.  According to the analysis, however, with the easily measurable soil parameters (bulk density, particle size distribution and humus content) a better estimation of NAPL retention can be given. This estimation method (after extending the database) can be useful for modelling the fate and migration of NAPL or mapping the organic contaminant sensitivity of the soils. 

2019 ◽  
Vol 34 (1) ◽  
pp. 27-34
Author(s):  
Maysarah Maysarah ◽  
Nelvia Nelvia

The research aims to examine the effect of the application of waste processing palm oil mill (Empty Fruit Bunches and Palm Oil Mill Effluent) on soil physical properties. The research was conducted at the oil palm plantation at Pelalawan and Laboratory of Soil Science, Faculty of Agriculture, the University of Riau from March to May 2016. The study was conducted experimentally using a Completely Randomized Design (CRD), which consisted of 4 treatments (EFB, POME, EFB+POME and without application as control). Each treatment was repeated 3 times. EFB and POME have been applied to the land since 2001 with intervals giving every 6 months. Soil samples were applied EFB, POME, and EFB+POME taken on Blocks B3, Blocks B7 and Blocks C17. Soil samples were taken at a depth of 0-15 cm and 15-30 cm for disturbed and undisturbed soil. Parameters measured were soil water content, bulk density, particle density, total pore space, permeability, and soil color. Each parameter of the observed data was statistically analyzed using analysis of variance followed by Duncan's New Multiple Range Test (DNMRT) at 5% level,  while the soil color was descriptively analyzed. The results showed that the application of a mixture of EFB+POME increased soil moisture and bulk density decrease significantly and tended to increase the total pore space and permeability and tends to be lower particle density than controls, but it was not evident when compared EFB applications and POME alone. Applications waste processing palm oil mill affected the color of the soil where the soil is black on the application mix EFB+POME (hue: 10 YR, value/chroma: 2/1), brown on the application EFB (hue: 10 YR, value/chroma: 4/3 ), dark brown on the application of POME (hue: 10 YR, value/chroma: 3/3) and yellowish-brown in without application (hue: 10 YR, value/chroma: 5/4).


Solid Earth ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 75-90 ◽  
Author(s):  
Naseer Ahmad ◽  
Puneeta Pandey

Abstract. Land degradation leads to alteration of ecological and economic functions due to a decrease in productivity and quality of the land. The aim of the present study was to assess land degradation with the help of geospatial technology – remote sensing (RS) and geographical information system (GIS) – in Bathinda district, Punjab. The severity of land degradation was estimated quantitatively by analyzing the physico-chemical parameters in the laboratory to determine saline or salt-free soils and calcareous or sodic soils and further correlating them with satellite-based studies. The pH varied between 7.37 and 8.59, electrical conductivity (EC) between 1.97 and 8.78 dS m−1 and the methyl orange or total alkalinity between 0.070 and 0.223 (HCO3−) g L−1 as CaCO3. The spatial variability in these soil parameters was depicted through soil maps generated in a GIS environment. The results revealed that the soil in the study area was exposed to salt intrusion, which could be mainly attributed to irrigation practices in the state of Punjab. Most of the soil samples of the study area were slightly or moderately saline with a few salt-free sites. Furthermore, the majority of the soil samples were calcareous and a few samples were alkaline or sodic in nature. A comparative analysis of temporal satellite datasets of Landsat 7 ETM+ and Landsat 8 OLI_TIRS of 2000 and 2014, respectively, revealed that the water body showed a slight decreasing trend from 2.46 km2 in 2000 to 1.87 km2 in 2014, while the human settlements and other built-up areas expanded from 586.25 to 891.09 km2 in a span of 14 years. The results also showed a decrease in area under barren land from 68.9847 km2 in 2000 to 15.26 km2 in 2014. A significant correlation was observed between the digital number (DN) of the near-infrared band and pH and EC. Therefore, it is suggested that the present study can be applied to projects with special relevance to soil scientists, environmental scientists and planning agencies that can use the present study as baseline data to combat land degradation and conserve land resources in an efficient manner.


2017 ◽  
Vol 31 (3) ◽  
pp. 393-400 ◽  
Author(s):  
Renato Ribeiro Passos ◽  
Liovando Marciano da Costa ◽  
Igor Rodrigues de Assis ◽  
Danilo Andrade Santos ◽  
Hugo Alberto Ruiz ◽  
...  

AbstractThe efficient use of water is increasingly important and proper soil management, within the specificities of each region of the country, allows achieving greater efficiency. The South and Caparaó regions of Espírito Santo, Brazil are characterized by relief of ‘hill seas’ with differences in the degree of pasture degradation due to sun exposure. The objective of this study was to evaluate the least limiting water range in Udox soil under degraded pastures with two faces of exposure to the sun and three pedoenvironments. In each pedoenvironment, namely Alegre, Celina, and Café, two areas were selected, one with exposure on the North/West face and the other on the South/East face. In each of these areas, undisturbed soil samples were collected at 0-10 cm depth to determine the least limiting water range. The exposed face of the pasture that received the highest solar incidence (North/West) presented the lowest values in least limiting water range. The least limiting water range proved to be a physical quality indicator for Udox soil under degraded pastures.


Jurnal Solum ◽  
2007 ◽  
Vol 4 (1) ◽  
pp. 5
Author(s):  
Syafrimen Yasin ◽  
Gusnidar Gusnidar ◽  
Dedy Iskandar

A research conducted in Sungai Rumbai, Dharmasraya Regency and in Soil Laboratory Andalas university was aimed to evaluate soil fertility status on the depth below 0-20 cm from several land use types , especially under Mixed Garden and annual cultivated dryland soil.  Soil samples were taken on Ultisol at 0-8% slope (late-waving soil surface).  Land use types evaluated were forest, annual cultivated dryland, bush land, rangeland covered by Imperata cylindrica and mixed garden.  Composite soil samples for soil chemical analysis were taken on the 0-20 cm soil depth with four replications, and 5 drillings for each replication.  Undisturbed soil samples by using sample ring were used to analyze sol bulk volume.  The data resulted were compared to the criteria and were statistically tested using Analysis of Variance and then were continued by LSD at 5% level.  From the results of analyses could be concluded that land use  for mixed garden had the higher Organic Carbon (OC) content and the lower bulk volume (BV) than those for annual cultivated dryland soil.Key Words: Degradasi Lahan, Kebun Campuran, Tegalan


2020 ◽  
Vol 22 (2) ◽  
pp. 149-155
Author(s):  
Iskandar ◽  
Rabiya

Soil consolidation testing using an oedometer and rowe cell. Oedometers are often used on clay and soft soils. However, in the development of the rowe cell device, the results of lowering soft soil were better than the oedometer. The advantage of this rowe cell is that it can determine the saturation value of the soil samples tested. The rowe cell tester can measure the pore water pressure at the beginning and end of each consolidation stage. This rowe cell can provide suitable settlement for soft soils. This consolidation test to obtain soil parameters such as Cv and Cc by using the rowe cell tool. After that, from the test results, the two tools were compared.


Author(s):  
Kent McKnight ◽  
Kimball Harper ◽  
Karl McKnight

The primary overall objective of inventorying the macrofungi growing in and around Grand Teton and Yellowstone National Parks was partially achieved with the published checklist (McKnight 1982) and additions from the 1982 Research Center Annual Report (McKnight, Harper, & McKnight 1984). The intensive collecting of the 1982 fruiting season including a 12-week phenological study at 11 selected sites left many species unidentified and numerous others observed but not collected, or with inadequately annotated collections made. Litter and soil moisture data for the 11 study stands are also given in the 1982 annual report cited above, as well as data on 15 overstory and understory vegetation and soil parameters. Field studies in the Parks during the summer of 1983 concentrated on (1) identification of chlorophyllous and vascular plants at the 11 sites selected for concentrated study in 1982; (2) quantitative estimates of chlorophyllous plant cover and height; (3) estimates of site quality; (4) collections of composite soil samples; and (5) additional records of macrofungi for the Parks with supporting data in the form of photographs, drawings, and annotations.


2005 ◽  
Vol 62 (5) ◽  
pp. 493-497 ◽  
Author(s):  
Herdjania Veras de Lima ◽  
Álvaro Pires da Silva ◽  
Sílvia Imhoff ◽  
Afrânio Ferreira Neves Junior

Due to the narrow window of ideal moisture conditions required for collecting undisturbed soil samples from hardsetting horizons in the field, this study compared the efficiency of an alternative method of soil core removal in the laboratory with that of the traditional field method by using measurements of soil bulk density data (Db). In a first sampling, cylinders were removed with a soil sampler in the field. In a second sampling, large soil blocks were removed with Kubiena-type zinc (brass) boxes in the field. Volumetric core cylinder samples were removed from these blocks in the laboratory with a manual hydraulic pump. There were no differences between the Db values determined from the laboratory and the field coring method. The laboratory method was considered more efficient than the field method because it allowed reductions in the errors made by operators in the field, and those caused by differences in soil water content. The laboratory method allows sampling in hardsetting horizons throughout the year, and collecting soil core samples under conditions of controlled moisture and applied force.


2011 ◽  
Vol 35 (8) ◽  
pp. 604-622 ◽  
Author(s):  
Hirotaka Fukuhara ◽  
Akihito Kamata

A differential item functioning (DIF) detection method for testlet-based data was proposed and evaluated in this study. The proposed DIF model is an extension of a bifactor multidimensional item response theory (MIRT) model for testlets. Unlike traditional item response theory (IRT) DIF models, the proposed model takes testlet effects into account, thus estimating DIF magnitude appropriately when a test is composed of testlets. A fully Bayesian estimation method was adopted for parameter estimation. The recovery of parameters was evaluated for the proposed DIF model. Simulation results revealed that the proposed bifactor MIRT DIF model produced better estimates of DIF magnitude and higher DIF detection rates than the traditional IRT DIF model for all simulation conditions. A real data analysis was also conducted by applying the proposed DIF model to a statewide reading assessment data set.


2021 ◽  
Author(s):  
Hayfa Zayani ◽  
Youssef Fouad ◽  
Didier Michot ◽  
Zeineb Kassouk ◽  
Zohra Lili-Chabaane ◽  
...  

<p>Visible-Near Infrared (Vis-NIR) spectroscopy has proven its efficiency in predicting several soil properties such as soil organic carbon (SOC) content. In this preliminary study, we explored the ability of Vis-NIR to assess the temporal evolution of SOC content. Soil samples were collected in a watershed (ORE AgrHys), located in Brittany (Western France). Two sampling campaigns were carried out 5 years apart: in 2013, 198 soil samples were collected respectively at two depths (0-15 and 15-25 cm) over an area of 1200 ha including different land use and land cover; in 2018, 111 sampling points out of 198 of 2013 were selected and soil samples were collected from the same two depths. Whole samples were analyzed for their SOC content and were scanned for their reflectance spectrum. Spectral information was acquired from samples sieved at 2 mm fraction and oven dried at 40°C, 24h prior to spectra acquisition, with a full range Vis-NIR spectroradiometer ASD Fieldspec®3. Data set of 2013 was used to calibrate the SOC content prediction model by the mean of Partial Least Squares Regression (PLSR). Data set of 2018 was therefore used as test set. Our results showed that the variation ∆SOC<sub>obs</sub><sub></sub>obtained from observed values in 2013 and 2018 (∆SOC<sub>obs</sub> = Observed SOC (2018) - Observed SOC (2013)) is ranging from 0.1 to 25.9 g/kg. Moreover, our results showed that the prediction performance of the calibrated model was improved by including 11 spectra of 2018 in the 2013 calibration data set (R²= 0.87, RMSE = 5.1 g/kg and RPD = 1.92). Furthermore, the comparison of predicted and observed ∆SOC between 2018 and 2013 showed that 69% of the variations were of the same sign, either positive or negative. For the remaining 31%, the variations were of opposite signs but concerned mainly samples for which ∆SOCobs is less than 1,5 g/kg. These results reveal that Vis-NIR spectroscopy was potentially appropriate to detect variations of SOC content and are encouraging to further explore Vis-NIR spectroscopy to detect changes in soil carbon stocks.</p>


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