Semiempirical correlation between thermal conductivity and electrical resistivity for silt and silty clay soils

Geophysics ◽  
2019 ◽  
Vol 84 (3) ◽  
pp. MR99-MR105 ◽  
Author(s):  
Qiang Sun ◽  
Chao Lü
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Water Content ◽  
Clay Soil ◽  
Clay Soils ◽  
Theoretical Equation ◽  
Physical Parameters ◽  
Silty Clay ◽  
Silty Clay Soil ◽  
Gravimetric Water Content

Previous researchers have shown that thermal conductivity and electrical resistivity are related to the water content and void ratio of soil. The objective of this study is to present a theoretical relationship between these two physical parameters. A de Vries equation and Archie’s law are applied to develop a new theoretical equation that relates thermal conductivity to the electrical resistivity of soil. The DRE-2C thermal conductivity tester, which uses a transient plane-source method, is used to measure the thermal conductivity. In addition, the DDC-8 resistivity meter is used to measure the electrical resistivity. Experiments on the thermal conductivity and electrical resistivity of silt soil and silty clay soil with different gravimetric water contents and densities are performed. The results indicate that the theoretical equation can well explain the relationship between the thermal conductivity and electrical resistivity of silt and silty clay soils. The thermal conductivity and electrical resistivity are also found to have a linear relationship with the density of silt soil. When the gravimetric water content is less than 30%, the thermal conductivity and electrical resistivity of silty clay soil increase linearly with the density. The thermal conductivity increases with the gravimetric water content to a critical threshold depending on the soil type. The silty clay samples with a water content of 20% have the largest value of thermal conductivity. The electrical resistivity of the silt and silty clay samples decreases rapidly due to the increased pore connectivity and enhanced hydration of ions in soil with the increased water content. The results of the experiments indicate that the new theoretical equation is effective for estimating the soil electrical resistivity from the soil thermal conductivity.

Rice (Oryza sativa) response to clomazone

Weed Science ◽  
1998 ◽  
Vol 46 (3) ◽  
pp. 374-380 ◽  
Author(s):  
David L. Jordan ◽  
Patrick K. Bollich ◽  
Ann B. Burns ◽  
Douglas M. Walker
Keyword(s):  
Oryza Sativa ◽  
Grain Yield ◽  
Field Experiments ◽  
Clay Soil ◽  
Clay Soils ◽  
Silty Clay ◽  
Silt Loam ◽  
Loam Soil ◽  
Silty Clay Soil ◽  
Additional Field

Experiments were conducted in 1993 and 1994 to determine if seed treated with disulfoton at 3, 6, or 12 g ai kg−1 reduced bleaching of rice foliage caused by clomazone applied delayed preemergence at 0.56, 1.1, 1.7, or 2.2 kg ai ha−1 on silt loam and silty clay soils. Clomazone injured rice more on silt loam soil than on silty clay soil. Disulfoton reduced bleaching caused by clomazone. In additional field experiments conducted during 1995 and 1996, clomazone at rates as high as 2.2 kg ha−1 did not affect grain yield in seven of 10 experiments. Clomazone at rates below 1.7 kg ha−1 did not reduce grain yield in any of the experiments.

scholarly journals Semiempirical Correlation between P-Wave Velocity and Thermal Conductivity of Frozen Silty Clay Soil

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Yadong Ji ◽  
Kaipeng Zhu ◽  
Chao Lyu ◽  
Shidong Wang ◽  
Dianyan Ning ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Wave Velocity ◽  
Clay Soil ◽  
P Wave ◽  
Unfrozen Water ◽  
Silty Clay ◽  
Geothermal Systems ◽  
Unfrozen Water Content ◽  
P Wave Velocity ◽  
Silty Clay Soil

In this study, the thermal conductivity and P-wave velocity of silty clay soil with different water contents are investigated through experiments at different temperatures, and a theoretical correlation between thermal conductivity and wave velocity is established. With temperature decline, the unfrozen water content is reduced and frost heave cracks propagate in soil samples. The variations in thermal conductivity and P-wave velocity are summarized as four phases. The freezing temperature of silty clay soil is between −2°C and −4°C. There is an inversely proportional relationship between thermal conductivity and P-wave velocity for silty clay soil at temperatures below freezing. The experimental results show that the theoretical correlation can well explain the relationship between P-wave velocity and thermal conductivity. These findings provide a possibility for determining the thermal conductivity easily and quickly in geothermal systems and underground engineering projects.

scholarly journals Conventional and Conservation Seedbed Preparation Systems for Wheat Planting in Silty-Clay Soil

2021 ◽  
Vol 13 (11) ◽  
pp. 6506
Author(s):  
Roberto Fanigliulo ◽  
Daniele Pochi ◽  
Pieranna Servadio
Keyword(s):  
Clay Soil ◽  
Conservation Tillage ◽  
Field Tests ◽  
Superficial Layer ◽  
Soil Tillage ◽  
Energy Requirements ◽  
Silty Clay ◽  
Wide Range ◽  
Seedbed Preparation ◽  
Silty Clay Soil

Conventional seedbed preparation is based on deep ploughing followed by lighter and finer secondary tillage of the superficial layer, normally performed by machines powered by the tractor’s Power Take-Off (PTO), which prepares the seedbed in a single pass. Conservation methods are based on a wide range of interventions, such as minimum or no-tillage, by means of machines with passive action working tools which require two or more passes The aim of this study was to assess both the power-energy requirements of conventional (power harrows and rotary tillers with different working width) and conservation implements (disks harrow and combined cultivator) and the soil tillage quality parameters, with reference to the capability of preparing an optimal seedbed for wheat planting. Field tests were carried out on flat, silty-clay soil, using instrumented tractors. The test results showed significant differences among the operative performances of the two typologies of machines powered by the tractor’s PTO: the fuel consumption, the power and the energy requirements of the rotary tillers are strongly higher than power harrows. However, the results also showed a decrease of these parameters proceeding from conventional to more conservation tillage implements. The better quality of seedbed was provided by the rotary tillers.

scholarly journals Soil Texture Alters the Impact of Salinity on Carbon Mineralization

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 128
Author(s):  
Ruihuan She ◽  
Yongxiang Yu ◽  
Chaorong Ge ◽  
Huaiying Yao
Keyword(s):  
Soil Texture ◽  
Clay Soil ◽  
Sandy Loam ◽  
Microbial Community Composition ◽  
Clay Content ◽  
Interactive Effects ◽  
Silty Clay ◽  
C Mineralization ◽  
Negative Effect ◽  
Silty Clay Soil

Soil salinization typically inhibits the ability of decomposer organisms to utilize soil organic matter, and an increase in soil clay content can mediate the negative effect of salinity on carbon (C) mineralization. However, the interactive effects of soil salt concentrations and properties on C mineralization remain uncertain. In this study, a laboratory experiment was performed to investigate the interactive effects of soil salt content (0.1%, 0.3%, 0.6% and 1.0%) and texture (sandy loam, sandy clay loam and silty clay soil with 6.0%, 23.9% and 40.6% clay content, respectively) on C mineralization and microbial community composition after cotton straw addition. With increasing soil salinity, carbon dioxide (CO2) emissions from the three soils decreased, but the effect of soil salinity on the decomposition of soil organic carbon varied with soil texture. Cumulative CO2 emissions in the coarse-textured (sandy loam and sandy clay loam) soils were more affected by salinity than those in the fine-textured (silty clay) soil. This difference was probably due to the differing responses of labile and resistant organic compounds to salinity across different soil texture. Increased salinity decreased the decomposition of the stable C pool in the coarse-textured soil, by reducing the proportion of fungi to bacteria, whereas it decreased the mineralization of the active C pool in the fine-textured soil through decreasing the Gram-positive bacterial population. Overall, our results suggest that soil texture controlled the negative effect of salinity on C mineralization through regulating the soil microbial community composition.

scholarly journals Analysis of 2,4-D Concentration in Silty Clay Soil Under Two Irrigation Regimes Using LEACHP and PRZM-3 Models

2016 ◽  
Vol 19 (74) ◽  
pp. 77-88 ◽  
Author(s):  
M. Noshadi ◽  
S. Jamshidi ◽  
F. Foroharfar ◽  
◽  
◽  
...  
Keyword(s):  
Clay Soil ◽  
Silty Clay ◽  
Irrigation Regimes ◽  
Silty Clay Soil

Contaminant migration in engineered clay barriers due to heat and moisture redistribution under freezing conditions

1995 ◽  
Vol 32 (1) ◽  
pp. 40-59 ◽  
Author(s):  
Abdel M.O. Mohamed ◽  
Raymond N. Yong ◽  
Miroslawa T. Mazus
Keyword(s):  
Temperature Distribution ◽  
Temperature Gradient ◽  
Fluid Intake ◽  
Clay Soil ◽  
Soil Column ◽  
Silty Clay ◽  
Freezing Time ◽  
Contaminant Migration ◽  
Unfrozen Water Content ◽  
Silty Clay Soil

In this study, the effect of temperature distribution and its influence on contaminant migration in a silty clay soil were examined. Three series of freezing-column tests were performed with three different fluids: distilled water, municipal waste leachate, and heavy metal – leachate solution. It was found that temperature distribution as a function of space and time was similar in all tests, most likely as a result of the limited amount of fluid intake. Moisture redistributions were varied as a function of experiment duration and the type of fluid used. The amount of fluid intake was directly related to the freezing time and the temperature gradient in the freezing column. The amount of unfrozen water content, ion concentration and temperature gradient were the controlling parameters that contributed to the contaminant transport in the frozen illitic silty clay soil. Na+-concentration profiles were mostly dependent on water movement in the soil column. The behaviour of Ca2+ and Mg2+ cations was similar to Na+; their concentrations in the soil solution decreased with freezing time due to ion exchange. The large accumulations of Pb2+, Zn2+, Cu2+, and Cd2+ in the lower 10 mm of the soil column occurred as a result of cation exchange and precipitation mechanisms. Key words : unsaturated, osmotic, diffusion, buffer, exchange, transport.

scholarly journals Sunflower response to Boron supply when grown in a silty clay soil

2020 ◽  
Vol 19 (1) ◽  
pp. 81-86
Author(s):  
Dhassi Khalid ◽  
Drissi Saad ◽  
Makroum Kacem ◽  
Nasreddine Fatima Ezzahra ◽  
Amlal Fouad ◽  
...  
Keyword(s):  
Clay Soil ◽  
Silty Clay ◽  
Silty Clay Soil
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