CONVERSION OF ELECTROMAGNETIC INDUCTANCE READINGS TO SATURATED PASTE EXTRACT VALUES IN SOILS FOR DIFFERENT TEMPERATURE, TEXTURE, AND MOISTURE CONDITIONS

1989 ◽  
Vol 69 (1) ◽  
pp. 25-32 ◽  
Author(s):  
R. C. McKENZIE ◽  
W. CHOMISTEK ◽  
N. F. CLARK
Keyword(s):  
Electrical Conductivity ◽  
Soil Moisture ◽  
Soil Temperature ◽  
Key Words ◽  
Soil Salinity ◽  
Electromagnetic Induction ◽  
Linear Equations ◽  
Temperature Correction ◽  
Available Soil Moisture ◽  
Moisture Conditions

Linear equations were developed for converting electromagnetic induction readings (ECa) from EM38 meters to saturated paste electrical conductivity values (ECc). To correlate EM38 readings with measured ECe values, field sites representing a range of salinity conditions were sampled in 0.30-m increments to a depth of 1.5 m. Adapting a weighting procedure based on the EM38 meter's response to depth, ECe values were condensed into a single weighted value. The weighted ECe values were linearly correlated with temperature-corrected ECa readings. Equations were designed for soils of various textures under varying temperature and moisture conditions. For accurate ECa to ECe conversions, soil temperature correction of ECa is essential. When a frozen layer is present, EM38 readings are unreliable. EM38 horizontal and vertical modes show different ECa readings for the same depth-weighted ECe. Variability of ECa to ECe conversion was greater on coarse-textured than medium- or fine-textured soils. Available soil moisture should be above 30% for accurate ECe determinations from ECa readings. Key words: Salinity methods, soil salinity, saturated paste extract method, electromagnetic inductance meters, soil temperature

Soil salinity monitoring and detection of obstructed drainage pipes in the B-XII irrigation district (SW Spain) using electromagnetic induction sensing and inversion. 

2021 ◽  
Author(s):  
Mario Ramos ◽  
Mohhamad Farzamian ◽  
José Luis Gómez ◽  
Alfonso González ◽  
Benito Salvatierra ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Salinity ◽  
Electromagnetic Induction ◽  
Drainage System ◽  
State Agency ◽  
Irrigation District ◽  
Sw Spain ◽  
Hard Soil ◽  
Moisture Conditions ◽  
And Inversion

<p>Inversion of electromagnetic induction (EMI) signals is increasingly used for monitoring soil salinity in irrigated fields. In the B-XII irrigation district (SW Spain) the build-up of high salt concentrations in the topsoil is often related with a deficient performance of the underlying drainage system resulting in higher-than-average soil moisture conditions and salinization. This work aims at using EMI sensing and inversion to identify and localize problems (<em>e.g</em>. obstruction) with the drainage system in a 12.5 ha irrigated field in the B-XII irrigation district. The identified salinity hotspots in the EMI images are further validated using remotely sensed NDVI data and detailed information obtained during the cleaning of the drainage system, in addition to hard soil data. This study shows that EMI sensing and inversion can pinpoint problems with the drainage system that result in salinity hotspots and identify areas where the drainage system should be cleaned or substituted.</p><p> </p><p>This work is funded by the Spanish State Agency for Research through grants PID2019-104136RR-C21 and PID2019-104136RR-C22 and by IFAPA/FEDER through grant AVA2019.018.</p>

scholarly journals The roles of environmental variation and spatial distance in explaining diversity and biogeography of soil denitrifying communities in remote Tibetan wetlands

2020 ◽  
Vol 96 (5) ◽  
Author(s):  
Xiaoliang Jiang ◽  
Wenzhi Liu ◽  
Lunguang Yao ◽  
Guihua Liu ◽  
Yuyi Yang
Keyword(s):  
Electrical Conductivity ◽  
Soil Moisture ◽  
Soil Temperature ◽  
Community Composition ◽  
Environmental Filtering ◽  
Operational Taxonomic Unit ◽  
Amplicon Sequencing ◽  
Spatial Distance ◽  
Wetland Type ◽  
Α Diversity

ABSTRACT The relative importance of local environments and dispersal limitation in shaping denitrifier community structure remains elusive. Here, we collected soils from 36 riverine, lacustrine and palustrine wetland sites on the remote Tibetan Plateau and characterized the soil denitrifier communities using high-throughput amplicon sequencing of the nirS and nirK genes. Results showed that the richness of nirS-type denitrifiers in riverine wetlands was significantly higher than that in lacustrine wetlands but not significantly different from that in palustrine wetlands. There was no clear distinction in nir community composition among the three kinds of wetlands. Irrespective of wetland type, the soil denitrification rate was positively related to the abundance, but not the α-diversity, of denitrifying communities. Soil moisture, carbon availability and soil temperature were the main determinants of diversity [operational taxonomic unit (OTU) number] and abundance of thenirS-type denitrifier community, while water total organic carbon, soil NO3– and soil moisture were important in controlling nirK-type denitrifier diversity and abundance. The nirS community composition was influenced by water electrical conductivity, soil temperature and water depth, while the nirK community composition was affected by soil electrical conductivity. Spatial distance explained more variation in the nirS community composition than in the nirK community composition. Our findings highlight the importance of both environmental filtering and spatial distance in explaining diversity and biogeography of soil nir communities in remote and relatively undisturbed wetlands.

A RAPID METHOD FOR ESTIMATING WEIGHTED SOIL SALINITY FROM APPARENT SOIL ELECTRICAL CONDUCTIVITY MEASURED WITH AN ABOVEGROUND ELECTROMAGNETIC INDUCTION METER

1986 ◽  
Vol 66 (2) ◽  
pp. 315-321 ◽  
Author(s):  
N. C. WOLLENHAUPT ◽  
J. L. RICHARDSON ◽  
J. E. FOSS ◽  
E. C. DOLL
Keyword(s):  
Electrical Conductivity ◽  
Soil Salinity ◽  
Electrical Resistance ◽  
Electromagnetic Induction ◽  
Soil Depth ◽  
Soil Survey ◽  
Soil Electrical Conductivity ◽  
Simple Linear Regression ◽  
Survey Area ◽  
Parent Materials

This study presents a method for calibrating electromagnetic induction instrument readings with saturated paste electrical conductivity (ECe) for field mapping purposes. Each meter reading represents an integration of the apparent soil electrical conductivity (ECa) over the meter’s response depth. To correlate the meter readings with measured ECe within soil depth increments, several pedons representing a range of soil salinity for the survey area were sampled in 30-cm increments to a depth corresponding to the meter response. A weighting procedure based on the meter response-depth function was developed to condense the multiple ECe by depth measurements into a single weighted area specific value. These values were correlated with the apparent soil electric conductivity from the electromagnetic induction instrument by simple linear regression. This technique is designed for soil association of similar parent materials. The resulting regression equation yields a quick reliable equation that avoids complex mathematics and converts the instrument readings into weighted forms of commonly used saturated paste electrical conductivity values. Key words: Soil survey, electrical resistance

scholarly journals Electromagnetic Induction Measurements for Investigating Soil Salinization Caused by Saline Reclaimed Water

Atmosphere ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 73
Author(s):  
Lorenzo De Carlo ◽  
Gaetano Alessandro Vivaldi ◽  
Maria Clementina Caputo
Keyword(s):  
Electrical Conductivity ◽  
Soil Salinity ◽  
Electromagnetic Induction ◽  
Reclaimed Water ◽  
Soil Salinization ◽  
Repeated Measurements ◽  
Soil Electrical Conductivity ◽  
Geophysical Research ◽  
Soil Response ◽  
Short Period

This paper focused on the use of electromagnetic induction measurements in order to investigate soil salinization caused by irrigation with saline reclaimed water. An experimental activity was carried out during the growing season of tomato crop in order to evaluate expected soil salinization effects caused by different saline agro-industrial wastewaters used as irrigation sources. Soil electrical conductivity, strictly related to the soil salinity, has been monitored for three months by means of Electromagnetic Induction (EMI) measurements, and evident differences in the soil response have been observed. The study highlighted two aspects that can improve soil investigation due to the utilization of geophysical tools. First, EMI data can map large areas in a short period of time with an unprecedented level of detail by overcoming practical difficulties in order to massively sample soil. At the same time, repeated measurements over time allow updating real-time soil salinity maps by using accurate correlations with soil electrical conductivity. This application points out how integrated agro-geophysical research approaches can play a strategic role in agricultural saline water management in order to prevent soil salinization risks in medium to long-term periods.

scholarly journals Assessing the dynamics of soil salinity with time-lapse inversion of electromagnetic data guided by hydrological modelling

2021 ◽  
Vol 25 (3) ◽  
pp. 1509-1527
Author(s):  
Mohammad Farzamian ◽  
Dario Autovino ◽  
Angelo Basile ◽  
Roberto De Mascellis ◽  
Giovanna Dragonetti ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Soil Salinity ◽  
Electromagnetic Induction ◽  
Irrigation System ◽  
Time Lapse ◽  
Hydrological Modelling ◽  
Irrigated Agriculture ◽  
Field Assessment ◽  
Apparent Electrical Conductivity ◽  
Spatio Temporal

Abstract. Irrigated agriculture is threatened by soil salinity in numerous arid and semi-arid areas of the world, chiefly caused by the use of highly salinity irrigation water, compounded by excessive evapotranspiration. Given this threat, efficient field assessment methods are needed to monitor the dynamics of soil salinity in salt-affected irrigated lands and evaluate the performance of management strategies. In this study, we report on the results of an irrigation experiment with the main objective of evaluating time-lapse inversion of electromagnetic induction (EMI) data and hydrological modelling in field assessment of soil salinity dynamics. Four experimental plots were established and irrigated 12 times during a 2-month period, with water at four different salinity levels (1, 4, 8 and 12 dS m−1) using a drip irrigation system. Time-lapse apparent electrical conductivity (σa) data were collected four times during the experiment period using the CMD Mini-Explorer. Prior to inversion of time-lapse σa data, a numerical experiment was performed by 2D simulations of the water and solute infiltration and redistribution process in synthetic transects, generated by using the statistical distribution of the hydraulic properties in the study area. These simulations gave known spatio-temporal distribution of water contents and solute concentrations and thus of bulk electrical conductivity (σb), which in turn were used to obtain known structures of apparent electrical conductivity, σa. These synthetic distributions were used for a preliminary understanding of how the physical context may influence the EMI-based σa readings carried out in the monitored transects as well as being used to optimize the smoothing parameter to be used in the inversion of σa readings. With this prior information at hand, we inverted the time-lapse field σa data and interpreted the results in terms of concentration distributions over time. The proposed approach, using preliminary hydrological simulations to understand the potential role of the variability of the physical system to be monitored by EMI, may actually allow for a better choice of the inversion parameters and interpretation of EMI readings, thus increasing the potentiality of using the electromagnetic induction technique for rapid and non-invasive investigation of spatio-temporal variability in soil salinity over large areas.

scholarly journals Field Comparison of Electrical Resistance, Electromagnetic Induction, and Frequency Domain Reflectometry for Soil Salinity Appraisal

Soil Systems ◽  
2020 ◽  
Vol 4 (4) ◽  
pp. 61
Author(s):  
Fernando Visconti ◽  
José Miguel de Paz
Keyword(s):  
Electrical Conductivity ◽  
Frequency Domain ◽  
Soil Salinity ◽  
Electrical Resistance ◽  
Electromagnetic Induction ◽  
Linear Regression Models ◽  
Bulk Electrical Conductivity ◽  
Mass Fractions ◽  
Frequency Domain Reflectometry ◽  
Different Depths

By using different physical foundations and technologies, many probes have been developed for on-site soil salinity appraisal in the last forty years. In order to better understand their respective technical and practical advantages and constraints, comparisons among probes are needed. In this study, three different probes, based on electrical resistance (ER), electromagnetic induction (EMI), and frequency domain reflectometry (FDR), were compared during a field survey carried out in a large salt-threatened agricultural area. Information about the soil bulk electrical conductivity (σb) at different depths was obtained with each of the probes and, additionally, other soil properties were also measured depending on the specifications of each instrument and, moreover, determined in samples. On average, the EMI and FDR techniques could be regarded as equivalent for σb measurement, whereas ER gave higher σb values. Whatever the case, EMI, and also ER, had to be supplemented with information about soil clay, organic matter, and water mass fractions to attain, despite this effort, poor soil salinity estimations by means of multiple linear regression models (R2 < 0.5). On the contrary, FDR needed only probe data to achieve R2 of 0.7, though root mean standard error (RMSE) was still 1.5 dS m−1. The extra measurements and calculations that modern electrical conductivity contact probes integrate, specifically, those based on FDR, remarkably increase their ability for soil salinity appraisal, although there is still room for improvement.

Effects of madrone, chinkapin, and tanoak sprouts on light intensity, soil moisture, and soil temperature

1986 ◽  
Vol 16 (3) ◽  
pp. 654-658 ◽  
Author(s):  
Don Minore
Keyword(s):  
Soil Moisture ◽  
Light Intensity ◽  
Soil Temperature ◽  
Temperature Measurements ◽  
Moisture Conditions

Light, moisture, and temperature measurements beneath sprout clumps were compared with similar measurements outside the clumps on eight clear-cuttings in southwestern Oregon. Light intensity was higher beneath madrone than beneath tanoak or chinkapin. Soil moisture was higher beneath the clumps and soil temperature was lower than outside them during the cool moist summer of 1983. Soil temperature remained lower beneath the clumps during the warm dry summer of 1985, but moisture conditions were similar beneath and outside the clumps after the prolonged 1985 drought.

COMPARISON OF 1:1 AND 1:2 SUSPENSIONS AND EXTRACTS WITH THE SATURATION EXTRACT IN ESTIMATING SALINITY IN SASKATCHEWAN SOILS

1984 ◽  
Vol 64 (4) ◽  
pp. 699-704 ◽  
Author(s):  
T. J. HOGG ◽  
J. L. HENRY
Keyword(s):  
Electrical Conductivity ◽  
Key Words ◽  
Soil Salinity ◽  
Regression Coefficient ◽  
Fine Soil ◽  
Saturation Extract ◽  
Wide Range ◽  
Highly Correlated

Electrical conductivity of saturation extracts was related to that of 1:1 and 1:2 (soil:H2O) suspensions and extracts for a wide range of Saskatchewan soils. The conductivity of 1:1 extracts was 1.75 times greater than for 1:1 suspensions and the conductivity of 1:2 extracts was 1.38 times greater than that of 1:1 suspensions. The conductivity of the saturation extract was closely related to all of 1:1 extract or suspension; 1:2 extract or suspension (r = 0.96–0.98). The regression coefficient relating the conductivity of 1:1 and 1:2 extracts and suspensions to that of the saturated paste extract decreased in going from coarse to medium to fine soil textures. The concentrations of Na+, Ca2+ + Mg2+ and Cl− in 1:1 and 1:2 (soil:H2O) extracts were highly correlated with the amounts in the saturation extract (r = 0.93 to 0.99). Key words: Soil salinity, 1:1 and 1:2 suspension and extract, saturated paste

scholarly journals Soil temperature and soil moisture characteristics for several habitat types of Montana and Idaho

1996 ◽  
Author(s):  
◽  
Dean Albert Sirucek ◽  
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Temperature Regime ◽  
Western Montana ◽  
Thuja Plicata ◽  
Habitat Types ◽  
Soil Temperature Regime ◽  
Northern Idaho ◽  
Moisture Conditions ◽  
Climax Forest

Soil temperature and soil moisture data from sixty-six monitoring sites located in forest ecosystems of western Montana and northern Idaho were summarized. These data were analyzed in comparison to the criteria for soil temperature and soil moisture regimes (U.S.D.A.- Soil Taxonomy, Soils Staff, 1975). The hypothesis that climax forest communities (habitat types) occupy sites with characteristic soil temperature and moisture conditions was tested. The soil temperature and soil moisture status throughout the growing season for fifty-two monitoring sites was analyzed in respect to their climax forest series and habitat type class. The results of the analysis demonstrate that some forest habitat types of northern Idaho and western Montana occupy sites with a narrow range of soil temperature and soil moisture conditions; where as other habitat types have variable soil temperature and soil moisture conditions. The monitored soil temperature and soil moisture data were displayed for nineteen forest habitat types. Several relationships between climax forest vegetation, soil temperature regimes and soil moisture regimes were identified, for western Montana and northern Idaho. The Abies Iasiocarpa climax forest series monitoring sites classify primarily in the cryic soil temperature regime. The Thuja plicata, Abies grandis, and Pseudotsuga menziesii climax forest series monitoring sites classify primarily in the frigid soil temperature regime. In western Montana all the Abies lasiocarpa, Thuja plicata, and Abies grandis climax forest series monitoring sites classify in the udic soil moisture regime. The Pseudotsuga menziesii climax forest series monitoring sites classify in either a udic or a xeric soil moisture regime. It was concluded that a field soil scientist in western Montana or northern Idaho could estimate the soil temperature regime by knowing the climax forest series and elevation of a site. Discriminant analysis was applied to thirty-four monitoring sites representing six habitat types. The probability of the membership in a habitat type being correctly predicted by the site characteristics alone (i.e. average soil temperature, average soil moisture tension, and elevation) was eighty-six percent.

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