scholarly journals Comments to: A Novel Low-Cost Instrumentation System for Measuring the Water Content and Apparent Electrical Conductivity of Soils, Sensors, 15, 25546–25563

Sensors ◽  
2018 ◽  
Vol 18 (6) ◽  
pp. 1730 ◽  
Author(s):  
Xavier Chavanne ◽  
Alain Bruère ◽  
Jean-Pierre Frangi
Keyword(s):  
Electrical Conductivity ◽  
Water Content ◽  
Low Cost ◽  
Apparent Electrical Conductivity

scholarly journals A Novel Low-Cost Instrumentation System for Measuring the Water Content and Apparent Electrical Conductivity of Soils

Sensors ◽  
2015 ◽  
Vol 15 (10) ◽  
pp. 25546-25563 ◽  
Author(s):  
Alan Rêgo Segundo ◽  
José Martins ◽  
Paulo Monteiro ◽  
Rubens de Oliveira ◽  
Gustavo Freitas
Keyword(s):  
Electrical Conductivity ◽  
Water Content ◽  
Low Cost ◽  
Apparent Electrical Conductivity

scholarly journals Reply to Comments: A Novel Low-Cost Instrumentation System for Measuring the Water Content and Apparent Electrical Conductivity of Soils, Sensors, 15, 25546–25563

Sensors ◽  
2018 ◽  
Vol 18 (6) ◽  
pp. 1742 ◽  
Author(s):  
Alan Kardek Rêgo Segundo ◽  
Marco Jose da Silva ◽  
Gustavo Medeiros Freitas ◽  
Paulo Marcos de Barros Monteiro ◽  
José Helvecio Martins
Keyword(s):  
Electrical Conductivity ◽  
Water Content ◽  
Low Cost ◽  
Apparent Electrical Conductivity

scholarly journals SPATIAL CONTINUITY OF ELECTRICAL CONDUCTIVITY, SOIL WATER CONTENT AND TEXTURE ON A CULTIVATED AREA WITH CANE SUGAR

2018 ◽  
Vol 31 (2) ◽  
pp. 434-445
Author(s):  
JUCICLÉIA SOARES DA SILVA ◽  
ÊNIO FARIAS DE FRANÇA E SILVA ◽  
GLÉCIO MACHADO SIQUEIRA ◽  
GERÔNIMO FERREIRA DA SILVA ◽  
DIEGO HENRIQUE SILVA DE SOUZA
Keyword(s):  
Electrical Conductivity ◽  
Spatial Variability ◽  
Water Content ◽  
Integrated Management ◽  
Soil Layer ◽  
Cane Sugar ◽  
Spatial Continuity ◽  
Sugarcane Crop ◽  
Saturation Extract ◽  
Apparent Electrical Conductivity

ABSTRACT Spatial variability of soil attributes affects crop development. Thus, information on its variability assists in soil and plant integrated management systems. The objective of this study was to assess the spatial variability of the soil apparent electrical conductivity (ECa), electrical conductivity of the saturation extract (ECse), water content in the soil (θ) and soil texture (clay, silt and sand) of a sugarcane crop area in the State of Pernambuco, Brazil. The study area had about 6.5 ha and its soil was classified as orthic Humiluvic Spodosol. Ninety soil samples were randomly collected and evaluated. The attributes assessed were soil apparent electrical conductivity (ECa) measured by electromagnetic induction with vertical dipole (ECa-V) in the soil layer 0.0.4 and horizontal dipole (ECa-H) in the soil layer 0.0-1.5 m; and ECse, θ and texture in the soil layers 0.0-0.2 m and 0.2-0.4 m. Spatial variability of the ECa was affected by the area relief, and had no direct correlation with the electrical conductivity of the saturation extract (ECse). The results showed overestimated mean frequency distribution, with means distant from the mode and median. The area relief affected the spatial variability maps of ECa-V, ECa-H, ECse and θ, however, the correlation matrix did not show a well-defined cause-and-effect relationship. Spatial variability of texture attributes (clay, site and sand) was high, presenting pure nugget effect.

Study on Substrate Humidity, EC and Salinity In Situ Detection Technology

2010 ◽  
Vol 43 ◽  
pp. 361-365
Author(s):  
Qing Yuan Sheng ◽  
Ping Ping Li ◽  
Xi Liang Zhang ◽  
Zhi Gang Liu ◽  
Li Juan Zhao ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Physicochemical Properties ◽  
Water Content ◽  
Low Cost ◽  
Detection Accuracy ◽  
Special Equipment ◽  
Integrated Sensor ◽  
Detection Technology ◽  
Testing Medium

Considering the greater character differences between matrix and soil, and the great disparity in physicochemical properties of various substrate, now there is no special equipment to test matrix moisture, electrical conductivity (EC) and salinity of medium .On the basis of analyzing physicochemical properties of various substrate, the relationship between output voltage and water content is studied through piezoelectric type soil moisture probe trial. With "voltage-current" four-terminal method, multi-parameter integrated sensor testing medium moisture and electrical conductivities developed, and through the solution calibration EC measuring model is established. Then relationships among matrix water content, electrical conductivity and salinity are analyzed, and salinity testing model is established. A portable low-cost in-situ multi-parameter detection apparatus, testing substrate humidity, EC and salinities, developed by adopting MCU SPCE06A. Experimental results indicate that detection accuracy of the equipment can meet the need of soilless culture production, and it has greater application and dissemination value.

scholarly journals Bulk meltwater flow and liquid water content of snowpacks mapped using the electrical self-potential (SP) method

2016 ◽  
Vol 10 (1) ◽  
pp. 433-444 ◽  
Author(s):  
Sarah S. Thompson ◽  
Bernd Kulessa ◽  
Richard L. H. Essery ◽  
Martin P. Lüthi
Keyword(s):  
Electrical Conductivity ◽  
Water Content ◽  
Liquid Water ◽  
Low Cost ◽  
Sensor Arrays ◽  
Ground Truth ◽  
Liquid Water Content ◽  
Potential Method ◽  
Avalanche Forecasting ◽  
Self Potential

Abstract. Our ability to measure, quantify and assimilate hydrological properties and processes of snow in operational models is disproportionally poor compared to the significance of seasonal snowmelt as a global water resource and major risk factor in flood and avalanche forecasting. We show here that strong electrical self-potential fields are generated in melting in situ snowpacks at Rhone Glacier and Jungfraujoch Glacier, Switzerland. In agreement with theory, the diurnal evolution of self-potential magnitudes ( ∼  60–250 mV) relates to those of bulk meltwater fluxes (0–1.2  ×  10−6 m3 s−1) principally through the permeability and the content, electrical conductivity and pH of liquid water. Previous work revealed that when fresh snow melts, ions are eluted in sequence and electrical conductivity, pH and self-potential data change diagnostically. Our snowpacks had experienced earlier stages of melt, and complementary snow pit measurements revealed that electrical conductivity ( ∼  1–5  ×  10−6 S m−1) and pH ( ∼  6.5–6.7) as well as permeabilities (respectively  ∼  9.7  ×  10−5 and  ∼  4.3  ×  10−5 m2 at Rhone Glacier and Jungfraujoch Glacier) were invariant. This implies, first, that preferential elution of ions was complete and, second, that our self-potential measurements reflect daily changes in liquid water contents. These were calculated to increase within the pendular regime from  ∼  1 to 5 and  ∼  3 to 5.5 % respectively at Rhone Glacier and Jungfraujoch Glacier, as confirmed by ground truth measurements. We conclude that the electrical self-potential method is a promising snow and firn hydrology sensor owing to its suitability for (1) sensing lateral and vertical liquid water flows directly and minimally invasively, (2) complementing established observational programs through multidimensional spatial mapping of meltwater fluxes or liquid water content and (3)  monitoring autonomously at a low cost. Future work should focus on the development of self-potential sensor arrays compatible with existing weather and snow monitoring technology and observational programs, and the integration of self-potential data into analytical frameworks.

scholarly journals Assessing Effects of Salinity on the Performance of a Low-Cost Wireless Soil Water Sensor

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7041
Author(s):  
Srinivasa Rao Peddinti ◽  
Jan W. Hopmans ◽  
Majdi Abou Najm ◽  
Isaya Kisekka
Keyword(s):  
Electrical Conductivity ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Low Cost ◽  
Volumetric Soil Water Content ◽  
Sensor Performance ◽  
Water Sensor ◽  
Spatiotemporal Scales ◽  
Volumetric Soil Water

Low-cost, accurate soil water sensors combined with wireless communication in an internet of things (IoT) framework can be harnessed to enhance the benefits of precision irrigation. However, the accuracy of low-cost sensors (e.g., based on resistivity or capacitance) can be affected by many factors, including salinity, temperature, and soil structure. Recent developments in wireless sensor networks offer new possibilities for field-scale monitoring of soil water content (SWC) at high spatiotemporal scales, but to install many sensors in the network, the cost of the sensors must be low, and the mechanism of operation needs to be robust, simple, and consume low energy for the technology to be practically relevant. This study evaluated the performance of a resistivity–capacitance-based wireless sensor (Sensoterra BV, 1018LE Amsterdam, Netherlands) under different salinity levels, temperature, and soil types in a laboratory. The sensors were evaluated in glass beads, Oso Flaco sand, Columbia loam, and Yolo clay loam soils. A nonlinear relationship was exhibited between the sensor measured resistance (Ω) and volumetric soil water content (θ). The Ω–θ relationship differed by soil type and was affected by soil solution salinity. The sensor was extremely sensitive at higher water contents with high uncertainty, and insensitive at low soil water content accompanied by low uncertainty. The soil solution salinity effects on the Ω–θ relationship were found to be reduced from sand to sandy loam to clay loam. In clay soils, surface electrical conductivity (ECs) of soil particles had a more dominant effect on sensor performance compared to the effect of solution electrical conductivity (ECw). The effect of temperature on sensor performance was minimal, but sensor-to-sensor variability was substantial. The relationship between bulk electrical conductivity (ECb) and volumetric soil water content was also characterized in this study. The results of this study reveal that if the sensor is properly calibrated, this low-cost wireless soil water sensor has the potential of improving soil water monitoring for precision irrigation and other applications at high spatiotemporal scales, due to the ease of integration into IoT frameworks.

scholarly journals Laboratory Calibration and Field Validation of Soil Water Content and Salinity Measurements Using the 5TE Sensor

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5272 ◽  
Author(s):  
Zemni ◽  
Bouksila ◽  
Persson ◽  
Slama ◽  
Berndtsson ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Low Cost ◽  
Low Frequency ◽  
Field Conditions ◽  
Soil Electrical Conductivity ◽  
Application Range ◽  
Laboratory Calibration

Capacitance sensors are widely used in agriculture for irrigation and soil management purposes. However, their use under saline conditions is a major challenge, especially for sensors operating with low frequency. Their dielectric readings are often biased by high soil electrical conductivity. New calculation approaches for soil water content (θ) and pore water electrical conductivity (ECp), in which apparent soil electrical conductivity (ECa) is included, have been suggested in recent research. However, these methods have neither been tested with low-cost capacitance probes such as the 5TE (70 MHz, Decagon Devices, Pullman, WA, USA) nor for field conditions. Thus, it is important to determine the performance of these approaches and to test the application range using the 5TE sensor for irrigated soils. For this purpose, sandy soil was collected from the Jemna oasis in southern Tunisia and four 5TE sensors were installed in the field at four soil depths. Measurements of apparent dielectric permittivity (Ka), ECa, and soil temperature were taken under different electrical conductivity of soil moisture solutions. Results show that, under field conditions, 5TE accuracy for θ estimation increased when considering the ECa effect. Field calibrated models gave better θ estimation (root mean square error (RMSE) = 0.03 m3 m−3) as compared to laboratory experiments (RMSE = 0.06 m3 m−3). For ECp prediction, two corrections of the Hilhorst model were investigated. The first approach, which considers the ECa effect on K’ reading, failed to improve the Hilhorst model for ECp > 3 dS m−1 for both laboratory and field conditions. However, the second approach, which considers the effect of ECa on the soil parameter K0, increased the performance of the Hilhorst model and gave accurate measurements of ECp using the 5TE sensor for irrigated soil.

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