Estimation of Saturated Paste Extracts’ Electrical Conductivity from 1:5 Soil/Water Suspension and Gypsum

2011 ◽  
Vol 42 (3) ◽  
pp. 315-321 ◽  
Author(s):  
Farhad Khorsandi ◽  
Fateme Alaei Yazdi
Agropedology ◽  
2019 ◽  
Vol 27 (2) ◽  
Author(s):  
Yagani Sinha ◽  
◽  
Rajeev Srivastava ◽  
Jagdish Prasad ◽  
M.S.S. Nagaraju ◽  
...  

Soil salinity is a major environmental hazard which adversely affects plant growth, crop production, soil and water quality and agricultural productivity.Soil salinity is determined by measuring electrical conductivity of soil water suspension. Though saturation paste ECe closely relates with plant growth and development but its measurement is laborious and time-consuming specifically in clayey soils when large number of samples are analyzed. Measurement of EC1:2 (1:2 Soil: water suspension) is very quick and economical. Therefore, a need is felt to develop a relationship between ECe and EC1:2so that the values of EC1:2 could easily be related to ECe. For this, anexperiment was conducted on four soil series representing swell-shrink soils. Soils were artificially salinized with solutions (salt) of 0.2, 0.5, 1 and 2% of chloride salts (NaCl, CaCl2, MgCl2 and their mixture) and replicated three times. The results indicate that a significant relationship (r=0.96) exists between ECe and soil EC1:2and soil ECe can be reliably predicted from EC1:2 in swell-shrink soils.


2016 ◽  
Vol 30 (3) ◽  
pp. 349-357 ◽  
Author(s):  
Aura Pedrera-Parrilla ◽  
Eric C. Brevik ◽  
Juan V. Giráldez ◽  
Karl Vanderlinden

Abstract Understanding of soil spatial variability is needed to delimit areas for precision agriculture. Electromagnetic induction sensors which measure the soil apparent electrical conductivity reflect soil spatial variability. The objectives of this work were to see if a temporally stable component could be found in electrical conductivity, and to see if temporal stability information acquired from several electrical conductivity surveys could be used to better interpret the results of concurrent surveys of electrical conductivity and soil water content. The experimental work was performed in a commercial rainfed olive grove of 6.7 ha in the ‘La Manga’ catchment in SW Spain. Several soil surveys provided gravimetric soil water content and electrical conductivity data. Soil electrical conductivity values were used to spatially delimit three areas in the grove, based on the first principal component, which represented the time-stable dominant spatial electrical conductivity pattern and explained 86% of the total electrical conductivity variance. Significant differences in clay, stone and soil water contents were detected between the three areas. Relationships between electrical conductivity and soil water content were modelled with an exponential model. Parameters from the model showed a strong effect of the first principal component on the relationship between soil water content and electrical conductivity. Overall temporal stability of electrical conductivity reflects soil properties and manifests itself in spatial patterns of soil water content.


2015 ◽  
Vol 14 ◽  
pp. 70-90 ◽  
Author(s):  
Caley K. Gasch ◽  
Tomislav Hengl ◽  
Benedikt Gräler ◽  
Hanna Meyer ◽  
Troy S. Magney ◽  
...  

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Glécio Machado Siqueira ◽  
Jorge Dafonte Dafonte ◽  
Montserrat Valcárcel Armesto ◽  
Ênio Farias França e Silva

The apparent soil electrical conductivity (ECa) was continuously recorded in three successive dates using electromagnetic induction in horizontal (ECa-H) and vertical (ECa-V) dipole modes at a 6 ha plot located in Northwestern Spain. One of the ECadata sets was used to devise an optimized sampling scheme consisting of 40 points. Soil was sampled at the 0.0–0.3 m depth, in these 40 points, and analyzed for sand, silt, and clay content; gravimetric water content; and electrical conductivity of saturated soil paste. Coefficients of correlation between ECaand gravimetric soil water content (0.685 for ECa-V and 0.649 for ECa-H) were higher than those between ECaand clay content (ranging from 0.197 to 0.495, when different ECarecording dates were taken into account). Ordinary and universal kriging have been used to assess the patterns of spatial variability of the ECadata sets recorded at successive dates and the analyzed soil properties. Ordinary and universal cokriging methods have improved the estimation of gravimetric soil water content using the data of ECaas secondary variable with respect to the use of ordinary kriging.


2020 ◽  
Vol 19 (4) ◽  
pp. 507-516
Author(s):  
Le Ngoc Thanh ◽  
Nguyen Quang Dung ◽  
Luu Hai Tung

Assessment of soil and soil-water salinity is essential in agricultural production, therefore it is necessary to find out the non-costly, effective, rapid and reliable integrated methodology for this purpose. The paper presents the results of using the electromagnetic induction instrument EM31-MK2Ô in combination with collecting and analyzing soil and soil-water samples, and applying GIS and geostatistical techniques to assess the current status of soil and soil-water salinity in Ben Tre province. Apparent soil electrical conductivity ECa measured from ground surface to 6 m in depth increases from inland to the sea in northwest - southeast direction; ECa is closely related to topsoil salinity to 30 cm deep and to soil-water salinity at depth of 10–100 cm. Current status of soil and soil-water salinity in 2018 was assessed with a 4-fold increase in information, from 16 km2/data point to 4 km2/data point. Consequently four maps were established, consisting of electrical conductivity ECe and total solube salt TSS distributions of soil; electrical conductivity σw and total dissolved solid TDS distributions of soil-water.


1981 ◽  
Vol 21 (110) ◽  
pp. 303 ◽  
Author(s):  
PJ White ◽  
MJ Whitehouse ◽  
LA Warrell ◽  
PR Burrill

The relation between phosphate-extractable sulfate and the response of lucerne to applied sulfur was examined on 20 established lucerne (Medicago sativa) swards on the black earths of the Darling Downs. Two rates of S were used (0.100 kg ha-1) and soil depths to 90 cm were considered. Six sites responded at the first cut and relative yield of lucerne was correlated with soil sulfate. The best fit of the data was obtained using a square root quadratic model and sulfate in the 0-80 cm zone. The critical soil level was 3.5 ppm. Of 17 attributes examined, only chloride concentration (0-60 cm) and conductivity of the soil water suspension (0-60 cm) significantly improved the variance in relative yield explained, but this was considered to be fortuitous. The relative importance of sub-soil sulfate (40-80 cm) to lucerne nutrition on these soils is shown.


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