Four-Year Summary of the Use of Soil Conductivity as a Measure of Soil and Crop Status

It is of great significance to obtain soil texture information quickly for the realization of farmland management. Soil with good particle condition can well regulate the needs of plants for water, nutrients, air, and temperature during crop growth, thereby promoting high crop yields. The existing methods of measuring soil texture cannot meet the requirements of time and spatial resolution. For this reason, a vehicle-mounted soil texture detector was designed and developed based on machine vision and soil electrical conductivity devices. The detector does not require pretreatment such as air-drying and screening of the soil, and completely uses the original information of the farmland. The whole process can obtain the soil texture information in real time, omitting the complicated chemical process, and saving manpower and material resources. The vehicle-mounted detector is divided into a mechanical part, a control part, and a display part. The mechanical part provides measurement support for the acquisition of soil texture information; the control part collects and processes signals and images; the measurement results can be intuitively observed and recorded on the display, and can be operated through the mobile phone. The vehicle-mounted detector obtains soil conductivity through 4 disc electrodes, while the vehicle-mounted industrial camera captures the soil surface image, and extracts texture parameters through image processing, takes EC and texture parameters as input, and the embedded SVM model of the instrument was used to perform soil texture prediction. In order to verify the measurement accuracy of the detector, farmland verification experiments were carried out on farmland loam in Tongzhou District and Haidian District of Beijing. The R2 of the correlation between the measured value of soil EC and the actual value was 0.75, and the accuracy of soil texture prediction was 84.86%. It shows that the developed vehicle-mounted soil texture detector can meet the requirements for rapid acquisition of farmland texture information.

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Location and Characterization of Subsurface Anomalies Using a Soil Conductivity Probe

Groundwater Monitoring & Remediation ◽

10.1111/j.1745-6592.2000.tb00265.x ◽

2000 ◽

Vol 20 (2) ◽

pp. 55-59 ◽

Cited By ~ 11

Author(s):

Frank P. Beck ◽

Patrick J. Clark ◽

Robert W. Puls

Keyword(s):

Conductivity Probe ◽

Soil Conductivity

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Soil Conductivity Meter

Encyclopedic Dictionary of Archaeology ◽

10.1007/978-3-030-58292-0_190822 ◽

2021 ◽

pp. 1277-1277

Keyword(s):

Soil Conductivity

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The use of saline water for irrigating rice in northern Australia

Australian Journal of Experimental Agriculture ◽

10.1071/ea9680491 ◽

1968 ◽

Vol 8 (33) ◽

pp. 491 ◽

Cited By ~ 1

Author(s):

RW Strickland

Keyword(s):

Fresh Water ◽

Saline Water ◽

Salt Water ◽

Growth And Yield ◽

Soluble Salts ◽

Reproductive Phase ◽

Panicle Number ◽

Soil Conductivity ◽

Restricted Use ◽

Reproductive Phases

A pot trial to assess the effect of salt water on growth and yield of rice in the Northern Territory of Australia was conducted in 1962-63. Two varieties were irrigated with three levels of salinity for varied durations in either the establishment or reproductive phases. Plant emergence was significantly depressed by soil conductivities in excess of 4 m-mhos/cm at 25�C. The restricted use of up to 3000 p.p.m. total soluble salts from 10 days after emergence and of up to 6000 p.p.m. from 20 days after emergence, followed by fresh water, had no effect on flowering time, vegetative or grain yields. The application of 3000 and 6000 p.p.m. total soluble salts in the reproductive phase reduced mean panicle number and grain yield of both varieties and straw yield of one variety. Use of saline water in the establishment phase followed by fresh water and drainage, reduced soil conductivity. In the reproductive phase it nullified the effect of previous fresh water flushing and tended to increase soil conductivity above original levels.

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Evaluation of Horizontal Electric Field from the Lightning Channel by Electromagnetic Field Equations of Moving Charges

International Journal of Antennas and Propagation ◽

10.1155/2019/4091586 ◽

2019 ◽

Vol 2019 ◽

pp. 1-8

Author(s):

Yunfeng Zhang ◽

Erchun Zhang ◽

Jialiang Gu

Keyword(s):

Electromagnetic Field ◽

Electric Field ◽

Finite Conductivity ◽

Lightning Flash ◽

Horizontal Distance ◽

Field Equations ◽

Long Distance ◽

Return Stroke ◽

Lightning Channel ◽

Soil Conductivity

The horizontal electric field from the lightning return-stroke channel is evaluated by the electromagnetic field equations of moving charges in this paper. When a lightning flash strikes the ground, the charges move upward the lightning channel at the return-stroke speed, thereby producing the electromagnetic fields. According to the electromagnetic field equations of moving charges, the detained charges, uniformly moving charges, and decelerating (or accelerating) charges in each segment of the channel generate electrostatic fields, velocity fields, and radiation fields, respectively. The horizontal component of the sum is the horizontal electric field over the perfectly conducting ground. For the real soil with finite conductivity, the Wait formula is used here for the evaluation of the horizontal electric field over the realistic soil. The proposed method can avoid the oscillation of the fields in the long distance by the FDTD method and the singularity problem of the integral equation by the Sommerfeld integral method. The influences of the return-stroke speed, distance, and soil conductivity on the horizontal electric field are also analyzed by the proposed method. The conclusions can be drawn that the horizontal electric field decreases with the increasing of the return-stroke speed; the negative offset increases with the increasing of horizontal distance and with the decreasing of the soil conductivity, thereby forming the bipolar waveform. These conclusions will be practically valuable for the protection of lightning-induced overvoltage on the transmission lines.

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Experimental Study on the Impact of Soil Conductivity on Underground Magneto-Inductive Channel

IEEE Antennas and Wireless Propagation Letters ◽

10.1109/lawp.2015.2423687 ◽

2015 ◽

Vol 14 ◽

pp. 1782-1785 ◽

Cited By ~ 10

Author(s):

Jing Ma ◽

Xiaotong Zhang ◽

Qiwei Huang ◽

Liang Cheng ◽

Mingyu Lu

Keyword(s):

Experimental Study ◽

Soil Conductivity ◽

The Impact

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Interpretation of electrical conductivity in a clay soil containing salts

Soil Research ◽

10.1071/sr9780311 ◽

1978 ◽

Vol 16 (3) ◽

pp. 311 ◽

Cited By ~ 7

Author(s):

AV Blackmore

Keyword(s):

Electrical Conductivity ◽

Clay Soil ◽

Soil Aggregates ◽

Exchangeable Cation ◽

Simple Relationship ◽

Stable Range ◽

Soil Electrical Conductivity ◽

Salt Exclusion ◽

Exclusion Mechanism ◽

Soil Conductivity

The use of directly measured electrical conductivity of soil to provide an index of soil salinity is discussed. It is suggested that if an anion exclusion mechanism within the microfabric of a wet clay soil can lead to a non-uniform, but stable, range of salt concentrations, then the validity of such an index would be jeopardized. Experiments involved the monitoring of soil electrical conductivity during leaching and diffusion of salts from stable clay-soil aggregates packed in columns and cells. The equilibrium values of conductivity are inversely related to exchangeable cation valence, but are not affected by the type of anion involved. The soil conductivity was often much smaller than the value inferred from the amount of salts actually extracted from the columns or contained in the small isolated electrical conductivity cells. The results are consistent with the operation of a salt exclusion mechanism in the smaller pores of the soil fabric. With monovalent cations and relatively low electrolyte concentrations, the trapping of salts within the microfabric is maximized, while in contrast, with aluminium and aged hydrogen clays the exclusion effect is almost completely suppressed, in accord with double-layer theory. If salts are retained against concentration gradients within the fine structure units of the soil, current-transmitting regions between the units are of correspondingly high resistance, and this is reflected in a soil electrical conductivity value that is low relative to the amount of electrolyte between the electrodes. The observed soil conductivity may, however, bear a simple relationship to the salt fraction of the soil actually 'available' to plant roots.

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