Measurement of apparent electrical conductivity of soil and the spatial variability of soil chemical properties by electromagnetic induction

Precision agriculture based on the physical and chemical properties of soil requires dense sampling to determine the spatial variability of these properties. This dense sampling is often expensive and time-consuming. One technique used to reduce sample numbers involves defining management zones based on information collected in the field. Some researchers have demonstrated the importance of soil electrical variables in defining management zones. The objective of this study was to evaluate the relationship between the spatial variability of the apparent electrical conductivity and the soil properties in the coffee production of mountain regions. Spatial variability maps were generated using a geostatistical method. Based on the spatial variability results, a correlation analysis, using bivariate Moran's index, was done to evaluate the relationship between the apparent electrical conductivity and soil properties. The maps of potassium (K) and remaining phosphorus (P-rem) were the closest to the spatial variability pattern of the apparent electrical conductivity.

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The use of electromagnetic induction to detect the spatial variability of the salt and clay contents of soils

Soil Research ◽

10.1071/sr9870021 ◽

1987 ◽

Vol 25 (1) ◽

pp. 21 ◽

Cited By ~ 126

Author(s):

BG Williams ◽

D Hoey

Keyword(s):

Electrical Conductivity ◽

Spatial Variability ◽

Electromagnetic Induction ◽

New South ◽

Clay Material ◽

Soluble Salts ◽

South Wales ◽

Apparent Electrical Conductivity ◽

Highly Correlated ◽

Land Use Practices

The apparent electrical conductivity (EC,) of a 250 ha area of the Riverine Plain in New South Wales was mapped using a Geonics EM 34/3 electromagnetic terrain conductivity meter. The EC, values obtained were highly correlated with both the total soluble salts and the total <2 km clay material to a depth of 15 m. The spatial variability of both these properties has a direct bearing on present and future land-use practices.

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The problem with “apparent electrical conductivity” in soil electromagnetic induction studies

10.1016/bs.agron.2020.08.002 ◽

2020 ◽

Author(s):

Juan Herrero ◽

Irish Lorraine B. Pabuayon

Keyword(s):

Electrical Conductivity ◽

Electromagnetic Induction ◽

Apparent Electrical Conductivity

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Spatial variability of soil chemical properties after coffee tree removal

Revista Brasileira de Ciência do Solo ◽

10.1590/s0100-06832009000500041 ◽

2009 ◽

Vol 33 (5) ◽

pp. 1507-1514 ◽

Cited By ~ 5

Author(s):

Sidney Rosa Vieira ◽

Osvaldo Guedes Filho ◽

Márcio Koiti Chiba ◽

Heitor Cantarella

Keyword(s):

Spatial Variability ◽

Spatial Dependence ◽

Crop Yields ◽

Management Strategies ◽

Chemical Properties ◽

Spherical Model ◽

Soil Chemical Properties ◽

Kriging Interpolation ◽

Geostatistical Methods ◽

Plant Removal

Assessing the spatial variability of soil chemical properties has become an important aspect of soil management strategies with a view to higher crop yields with minimal environmental degradation. This study was carried out at the Centro Experimental of the Instituto Agronomico, in Campinas, São Paulo, Brazil. The aim was to characterize the spatial variability of chemical properties of a Rhodic Hapludox on a recently bulldozer-cleaned area after over 30 years of coffee cultivation. Soil samples were collected in a 20 x 20 m grid with 36 sampling points across a 1 ha area in the layers 0.0-0.2 and 0.2-0.4 m to measure the following chemical properties: pH, organic matter, K+, P, Ca2+, Mg2+, potential acidity, NH4-N, and NO3-N. Descriptive statistics were applied to assess the central tendency and dispersion moments. Geostatistical methods were applied to evaluate and to model the spatial variability of variables by calculating semivariograms and kriging interpolation. Spatial dependence patterns defined by spherical model adjusted semivariograms were made for all cited soil properties. Moderate to strong degrees of spatial dependence were found between 31 and 60 m. It was still possible to map soil spatial variability properties in the layers 0-20 cm and 20-40 cm after plant removal with bulldozers.

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Short-range and regional spatial variability of soil chemical properties in an agro-ecosystem in eastern Croatia

CATENA ◽

10.1016/j.catena.2017.02.018 ◽

2017 ◽

Vol 154 ◽

pp. 50-62 ◽

Cited By ~ 20

Author(s):

Igor Bogunovic ◽

Sebastiano Trevisani ◽

Miranda Seput ◽

Darko Juzbasic ◽

Boris Durdevic

Keyword(s):

Spatial Variability ◽

Short Range ◽

Chemical Properties ◽

Soil Chemical Properties

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

Revista Caatinga ◽

10.1590/1983-21252018v31n220rc ◽

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.

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Characterization of the soil compaction based on the mapping of the apparent electrical conductivity

Revista Engenharia na Agricultura - REVENG ◽

10.13083/reveng.v29i1.12875 ◽

2021 ◽

Vol 29 ◽

Author(s):

Eduardo Leonel Bottega ◽

Eder Luís Sari ◽

Zanandra Boff de Oliveira ◽

Alberto Eduardo Knies

Keyword(s):

Electrical Conductivity ◽

Spatial Variability ◽

Soil Compaction ◽

Penetration Resistance ◽

Management Zones ◽

Mean Values ◽

Soil Penetration Resistance ◽

Apparent Electrical Conductivity ◽

Moisture Conditions

Based on the measurement of soil penetration resistance (PR), it is possible to identify compacted soil layers, where root growth may be harmed, affecting crop development and yield. The objective of this work was to analyze the use of management zones (MZ), delimited on the basis of mapping of the spatial variability of the soil apparent electrical conductivity (ECa), in the differentiation of soil compaction levels. The work was carried out in a 25.8-ha no-tillage area, cultivated under a center pivot. The ECa was measured under two soil moisture conditions (13.7 and 16.45%), using the Terram® equipment. Soil penetration resistance (PR) was measured using the SoloStar PLG5500 penetrograph. Based on the spatial variability ECa mapping, management zones (2, 3, and 4 zones) were delimited. The mean PR values ??of each MZ were compared by the t-test of means. It was possible to differentiate mean values ??of penetration resistance (PR), which vary from 0.9 to 2.10 MPa, from the characterization of management classes generated on the basis of the ECa spatial variability. The highest stratification of PR values ??was obtained as a function of sampling directed at delimited management zones when the soil had lower moisture content (13.7%). The highest mean PR values ??were obtained for the split of the ECa map into at least three classes. It was identified that for the study area there is no need to perform any mechanical decompaction operation.

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SPATIAL VARIABILITY OF SOIL APPARENT ELECTRICAL CONDUCTIVITY - EFFECT OF THE NUMBER OF SUBSAMPLES

Engenharia Agrícola ◽

10.1590/1809-4430-eng.agric.v41n3p396-401/2021 ◽

2021 ◽

Vol 41 (3) ◽

pp. 396-401

Author(s):

Emanoel Di Tarso dos S. Sousa ◽

Daniel M. de Queiroz ◽

Jorge T. F. Rosas ◽

Amélia L. do Nascimento

Keyword(s):

Electrical Conductivity ◽

Spatial Variability ◽

Apparent Electrical Conductivity

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

Hydrology and Earth System Sciences ◽

10.5194/hess-25-1509-2021 ◽

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.

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