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

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

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.

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

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.

scholarly journals Factors influencing spatial variability of soil apparent electrical conductivity

2001 ◽  
Vol 32 (19-20) ◽  
pp. 2993-3008 ◽  
Author(s):  
D. E. Clay ◽  
J. Chang ◽  
D. D. Malo ◽  
C. G. Carlson ◽  
C. Reese ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Spatial Variability ◽  
Factors Influencing ◽  
Apparent Electrical Conductivity

scholarly journals Spatial variability of apparent electrical conductivity and soil properties in a coffee production field

2014 ◽  
Vol 34 (6) ◽  
pp. 1224-1233 ◽  
Author(s):  
Domingos S. M. Valente ◽  
Daniel M. de Queiroz ◽  
Francisco de A. de C. Pinto ◽  
Fábio L. Santos ◽  
Nerilson T. Santos
Keyword(s):  
Electrical Conductivity ◽  
Spatial Variability ◽  
Soil Properties ◽  
Precision Agriculture ◽  
Chemical Properties ◽  
Coffee Production ◽  
Management Zones ◽  
Apparent Electrical Conductivity ◽  
The Relationship ◽  
Dense Sampling

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.

scholarly journals SPATIAL VARIABILITY OF APPARENT ELECTRICAL CONDUCTIVITY AND PHYSICOCHEMICAL ATTRIBUTES OF THE SOIL

2017 ◽  
Vol 26 (3) ◽  
pp. 469-482
Author(s):  
Elizeu De Souza Lima ◽  
Lenon Henrique Lovera ◽  
Rafael Montanari ◽  
Zigomar Menezes de Souza ◽  
Jose Luiz Rodrigues Torres
Keyword(s):  
Electrical Conductivity ◽  
Spatial Variability ◽  
Low Cost ◽  
Organic Matter Content ◽  
Matter Content ◽  
Potassium Cation ◽  
Entire Area ◽  
Mato Grosso ◽  
Management Zones ◽  
Apparent Electrical Conductivity

The apparent electrical conductivity has been an attribute widely used in studies of spatial variability, due to its high correlation with other soil attributes and because it is an attribute that represents the variability of an area in a quick, easy and low-cost way. The objective of this study was to evaluate the relationship between the spatial variability of apparent electrical conductivity with physicochemical attributes of an Eutrophic Red Oxisol located in Maracaju, state of Mato Grosso do Sul, Brazil, for determining specific soil management zones. We analyzed apparent electrical conductivity attributes (ECa 2, 7 and 15 kHz), contents of potassium, cation exchange capacity, clay, base saturation and organic matter content. ECa was measured with the Profiler EMP-400 crossing the entire area in 0.45 m spaced lines. Soil samples were collected in the 0.000.20 m layer, with a total of 216 samples in an area of 70 ha. Statistical and geostatistical analyses were performed by SAS and GS+ software. The apparent electrical conductivity (ECa) was presented as an important tool to identify specific management zones showing data variability between low and medium zones. The attributes that had higher correlation with apparent electrical conductivity were potassium and clay.

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

2016 ◽  
Vol 11 (39) ◽  
pp. 3751-3762 ◽  
Author(s):  
Machado Siqueira Glecio ◽  
Dafonte Dafonte Jorge ◽  
Paz Gonzalez Antonio ◽  
Valcarcel Armesto Monteserrat ◽  
Farias de Franca e Silva Enio ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Spatial Variability ◽  
Electromagnetic Induction ◽  
Chemical Properties ◽  
Soil Chemical Properties ◽  
Apparent Electrical Conductivity

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

Soil Research ◽  
1987 ◽  
Vol 25 (1) ◽  
pp. 21 ◽  
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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