scholarly journals Low-Input Estimation of Site-Specific Lime Demand Based on Apparent Soil Electrical Conductivity and In Situ Determined Topsoil pH

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5280
Author(s):  
Moritz von Cossel ◽  
Harm Druecker ◽  
Eberhard Hartung
Keyword(s):  
Electrical Conductivity ◽  
Field Measurements ◽  
Ex Situ ◽  
Soil Electrical Conductivity ◽  
Standard Equipment ◽  
Site Specific ◽  
Input Estimation ◽  
Low Input ◽  
North Germany

Site-specific liming helps increase efficiency in agricultural production. For adequate determination of the lime demand, a combination of apparent soil electrical conductivity (ECa) and topsoil pH can be used. Here, it was hypothesized that this can also be done at low-input level. Field measurements using the EM38 MK I (Geonics, Canada) were conducted on three experimental sites in north Germany in 2011. The topsoil pH was measured based on two approaches: on the field using a handheld pH meter (Spectrum-Technologies Ltd., Bridgend, UK) with a flat electrode (in situ), and in the lab using standard equipment (ex situ). Both soil ECa (0.4–35.9 mS m−1) and pH (5.13–7.41) were heterogeneously distributed across the sites. The same was true of the lime demand (−1.35–4.18 Mg ha−1). There was a significant correlation between in situ and ex situ determined topsoil pH (r = 0.89; p < 0.0001). This correlation was further improved through non-linear regression (r = 0.92; p < 0.0001). Thus, in situ topsoil pH was found suitable for map-overlay with ECa to determine the site-specific lime demand. Consequently, the hypothesis could be confirmed: The combined use of data from EM38 and handheld pH meters is a promising low-input approach that may help implement site-specific liming in developing countries.

scholarly journals Site-Specific Management Zones Based on Soil Electrical Conductivity in a Semiarid Cropping System

2003 ◽  
Vol 95 (2) ◽  
pp. 303 ◽  
Author(s):  
Cinthia K. Johnson ◽  
David A. Mortensen ◽  
Brian J. Wienhold ◽  
John F. Shanahan ◽  
John W. Doran
Keyword(s):  
Electrical Conductivity ◽  
Cropping System ◽  
Soil Electrical Conductivity ◽  
Site Specific ◽  
Management Zones ◽  
Specific Management

scholarly journals Microstructure and Electrical Property of Ex-Situ and In-Situ Copper Titanium Carbide Nanocomposites

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 735
Author(s):  
Nguyen Hoang Viet ◽  
Nguyen Thi Hoang Oanh
Keyword(s):  
Electrical Conductivity ◽  
Electron Microscope ◽  
Applied Pressure ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Spark Plasma

In this study, ex-situ Cu-TiC nanocomposites of 1, 3 and 5 vol. % TiC and in-situ Cu-TiH2-C nanocomposites (corresponding to 5 vol. % TiC) were prepared using ball milling and spark plasma sintering methods. Powder mixtures were milled for 4 h at 400 rpm. As-milled Cu-TiC composite powders were consolidated under an applied pressure of 70 MPa. The phase composition, and microstructure of the composite samples were characterized by X-ray diffraction, and scanning electron microscope and transmission electron microscope techniques, respectively. With the increasing TiC content from 1 to 5 vol. %, the hardness of the ex-situ composites when sintered at 600 °C changed between 161.4 and 178.5 HV and the electrical conductivity decreased from 52.1 to 47.6% IACS. In-situ Cu-TiH2-C nanocomposite sintered at 950 °C had higher hardness and electrical conductivity than ex-situ Cu-TiC composite due to having a homogenous distribution of nano reinforcement particles and dense structure.

scholarly journals Site-Specific Management Zones Based on Soil Electrical Conductivity in a Semiarid Cropping System

2003 ◽  
Vol 95 (2) ◽  
pp. 303-315 ◽  
Author(s):  
Cinthia K. Johnson ◽  
David A. Mortensen ◽  
Brian J. Wienhold ◽  
John F. Shanahan ◽  
John W. Doran
Keyword(s):  
Electrical Conductivity ◽  
Cropping System ◽  
Soil Electrical Conductivity ◽  
Site Specific ◽  
Management Zones ◽  
Specific Management

scholarly journals Biogeochemical Interactions In The Application Of Biotechnological Strategies To Marine Sediments Contaminated With Metals

2015 ◽  
Vol 14 (1) ◽  
pp. 12-31 ◽  
Author(s):  
Viviana Fonti ◽  
Antonio Dell’Anno ◽  
Francesca Beolchini
Keyword(s):  
Marine Sediments ◽  
Environmental Problem ◽  
Sediment Contamination ◽  
Metal Mobility ◽  
Ex Situ ◽  
Carbonate Content ◽  
Anthropogenic Pressure ◽  
Site Specific ◽  
Geochemical Properties

AbstractSediment contamination in coastal areas with high anthropogenic pressure is a widespread environmental problem. Metal contaminants are of particular concern, since they are persistent and cannot be degraded. Microorganisms can influence metal mobility in the sediment by several direct and indirect processes. However, the actual fate of metals in the environment is not easily predictable and several biogeochemical constraints affect their behaviour. In addition, the geochemical characteristics of the sediment play an important role and the general assumptions for soils or freshwater sediments cannot be extended to marine sediments. In this paper we analysed the correlation between metal mobility and main geochemical properties of the sediment. Although the prediction of metal fate in sediment environment, both forex-situbioleaching treatments andin-situbiostimulation strategies, appears to require metal-specific and site-specific tools, we found that TOM and pH are likely the main variables in describing and predicting Zn behaviour. Arsenic solubilisation/increase in mobility appears to correlate positively with carbonate content. Cd, Pb and Ni appear to require multivariate and/or non-linear approaches.

scholarly journals Integrated Electrokinetics-Adsorption Remediation of Saline-Sodic Soils: Effects of Voltage Gradient and Contaminant Concentration on Soil Electrical Conductivity

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Mohammed Hussain Essa ◽  
Nuhu Dalhat Mu’azu ◽  
Salihu Lukman ◽  
Alaadin Bukhari
Keyword(s):  
Electrical Conductivity ◽  
Contaminated Soils ◽  
Influential Factors ◽  
Polarity Reversal ◽  
Reversal Rate ◽  
Voltage Gradient ◽  
Contaminant Concentration ◽  
Soil Electrical Conductivity ◽  
Sodic Soils

In this study, an integrated in situ remediation technique which couples electrokinetics with adsorption, using locally produced granular activated carbon from date palm pits in the treatment zones that are installed directly to bracket the contaminated soils at bench-scale, is investigated. Natural saline-sodic clay soil, spiked with contaminant mixture (kerosene, phenol, Cr, Cd, Cu, Zn, Pb, and Hg), was used in this study to investigate the effects of voltage gradient, initial contaminant concentration, and polarity reversal rate on the soil electrical conductivity. Box-Behnken Design (BBD) was used for the experimental design and response surface methodology (RSM) was employed to model, optimize, and interpret the results obtained using Design-Expert version 8 platform. The total number of experiments conducted was 15 with voltage gradient, polarity reversal rate, and initial contaminant concentration as variables. The main target response discussed in this paper is the soil electrical conductivity due to its importance in electrokinetic remediation process. Responses obtained were fitted to quadratic models whoseR2ranges from 84.66% to 99.19% with insignificant lack of fit in each case. Among the investigated factors, voltage gradient and initial contaminant concentration were found to be the most significant influential factors.

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