The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Jan Seidel - One of the best experts on this subject based on the ideXlab platform.
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Soil pH mapping with an on the go sensor
Sensors, 2011Co-Authors: Michael Schirrmann, Robin Gebbers, Eckart Kramer, Jan SeidelAbstract:Soil pH is a key parameter for crop productivity, therefore, its spatial variation should be adequately addressed to improve precision management decisions. Recently, the Veris pH Manager™, a sensor for high-resolution mapping of Soil pH at the field scale, has been made commercially available in the US. While driving over the field, Soil pH is measured on-the-go directly within the Soil by ion selective antimony electrodes. The aim of this study was to evaluate the Veris pH Manager™ under farming conditions in Germany. Sensor readings were compared with data obtained by standard protocols of Soil pH assessment. Experiments took place under different scenarios: (a) controlled tests in the lab, (b) semicontrolled test on transects in a stop-and-go mode, and (c) tests under practical conditions in the field with the sensor working in its typical on-the-go mode. Accuracy issues, problems, options, and potential benefits of the Veris pH Manager™ were addressed. The tests demonstrated a high degree of linearity between standard laboratory values and sensor readings. Under practical conditions in the field (scenario c), the measure of fit (r2) for the regression between the on-the-go measurements and the reference data was 0.71, 0.63, and 0.84, respectively. Field-specific calibration was necessary to reduce systematic errors. Accuracy of the on-the-go maps was considerably higher compared with the pH maps obtained by following the standard protocols, and the error in calculating lime requirements was reduced by about one half. However, the system showed some weaknesses due to blockage by residual straw and weed roots. If these problems were solved, the on-the-go sensor investigated here could be an efficient alternative to standard sampling protocols as a basis for liming in Germany.
Viacheslav I. Adamchuk - One of the best experts on this subject based on the ideXlab platform.
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Agroeconomic Evaluation of Intense Soil pH Mapping
2001 Sacramento CA July 29-August 1 2001, 2020Co-Authors: Viacheslav I. Adamchuk, Mark T. Morgan, James M. Lowenber DeboerAbstract:A prototype of an automated Soil sampling system for measuring Soil pH on-the-go has been created and evaluated (Papers No. 98-3094 & 99-1100). It allows measuring Soil pH every 10 seconds while traveling across the field (automated Soil pH mapping). Geostatistical, agronomic and economic methods were used to generate a model for quantitative assessment of net return over cost of liming for different lime management techniques (including automated and grid Soil sampling, fixed and variable rate liming). This model allows one to conduct comparison analysis while changing various field parameters, costs, prices and other related constants.
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On-the-Go Mapping of Soil pH Using Antimony Electrodes
2008 Providence Rhode Island June 29 - July 2 2008, 2020Co-Authors: Viacheslav I. Adamchuk, Eric LundAbstract:Glass-membrane ion-selective electrodes represent the most common measurement means to determine the pH of an aquatic media. Automated engagement of such electrodes with naturally moist Soil samples allows implementation of on-the-go mapping of Soil pH. However, some early adopters of this technology reported heavy electrode abuse and occasional breakage in Soils with course texture and/or hard impurities. Antimony electrodes provide an alternative suitable for on-the-go mapping of Soil pH. This paper illustrates the results of laboratory and field experiments comparing Soil pH measurements obtained using glass-based and antimony-based ion-selective electrodes. It was concluded that measurements produced using an antimony electrode were of similar quality to the measurements done with a conventional glass electrode. However, the ability to withstand abrasion was much higher when Soil was engaged with an antimony electrode than with a glass membrane.
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Evaluation of an on-the-go technology for Soil pH mapping
Precision Agriculture, 2007Co-Authors: Viacheslav I. Adamchuk, Eric Lund, Todd M. Reed, Richard B. FergusonAbstract:Since conventional sampling and laboratory Soil analysis do not provide a cost effective capability for obtaining geo-referenced measurements with adequate frequency, different on-the-go sensing techniques have been attempted. One such recently commercialized sensing system combines mapping of Soil electrical conductivity and pH. The concept of direct measurement of Soil pH has allowed for a substantial increase in measurement density. In this publication, Soil pH maps, developed using on-the-go technology and obtained for eight production fields in six US states, were compared with corresponding maps derived from grid sampling. It was shown that with certain field conditions, on-the-go mapping can significantly increase the accuracy of Soil pH maps and therefore increase the potential profitability of variable rate liming. However, in many instances, these on-the-go measurements need to be calibrated to account for a field-specific bias. After calibration, the overall error estimate for Soil pH maps produced using on-the-go measurements was less than 0.3 pH, while non-calibrated on-the-go and conventional field average and grid-sampling maps produced errors greater than 0.4 pH.
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DEVELOPMENT OF AN ON-THE-GO Soil pH MAPPING METHOD: ANALYSIS OF MEASUREMENT VARIABILITY
Applied Engineering in Agriculture, 2006Co-Authors: Viacheslav I. Adamchuk, Mark T. Morgan, Sylvie M. BrouderAbstract:An automated system for mapping Soil pH on-the-go has been developed, tested, and commercialized. This system is capable of determining Soil pH approximately every 10 s as it moves across a field. When georeferenced, these measurements could be used to construct Soil pH maps that can be involved in farm management decision process. This method for on-the-go Soil pH mapping uses flat surface ion-selective electrodes to directly measure the pH of moist Soil. The prototype system was evaluated in a field with artificially created areas corresponding to acidic and neutral Soil conditions. Tests revealed that the resulting standard error (measurement error superimposed on the effects of Soil micro variability) was found to be 0.38 pH. The standard laboratory procedure (measurement of Soil pH in 1:1 weight-to-weight Soil-water solution) performed on the same set of samples resulted in 0.24 pH standard error. In addition, various laboratory experiments showed high correlation between Soil pH measured directly on naturally moist samples and Soil solutions (R2 = 0.93 - 0.96). Field evaluation of automated Soil pH mapping indicated that automated sampling did not introduce a significant source of error and produced the same variance of measurements within relatively homogeneous field areas as measurements performed directly on manually extracted Soil samples.
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A Model for Agro-Economic Analysis of Soil pH Mapping
Precision Agriculture, 2004Co-Authors: Viacheslav I. Adamchuk, Mark T. Morgan, James Lowenberg-deboerAbstract:Core Soil sampling followed by laboratory analysis is the traditional method used to map Soil pH prior to variable rate application (VRA) of lime on cropland. A recently developed automated Soil sampling system capable of measuring Soil pH on-the-go has significantly increased sampling resolution. However, adoption of such systems must be justified economically. This paper presents a method for assessing the economic benefit from automated mapping of Soil pH prior to variable rate lime application. In this work, geostatistical, agronomic, and economic methods were used to generate a comprehensive numerical model for quantitative assessment of the net return over cost of liming for different lime management strategies. The strategies included: automated pH mapping, manual grid Soil sampling, and whole field sampling used in combination with either variable or fixed rate liming. The model was demonstrated using a simulated field with known average pH and semivariogram model. The analysis showed the largest benefit ($6.13ha−1year−1) from using VRA with automated Soil pH mapping versus VRA based on 1ha (2.5acres) manual grid point sampling for the selected simulated field conditions. A sensitivity analysis demonstrated that for a wide range of field conditions and crop prices, VRA plus automated mapping promises higher relative benefits than VRA based on either manual grid point or grid cell sampling.
Michael Schirrmann - One of the best experts on this subject based on the ideXlab platform.
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Soil pH mapping with an on the go sensor
Sensors, 2011Co-Authors: Michael Schirrmann, Robin Gebbers, Eckart Kramer, Jan SeidelAbstract:Soil pH is a key parameter for crop productivity, therefore, its spatial variation should be adequately addressed to improve precision management decisions. Recently, the Veris pH Manager™, a sensor for high-resolution mapping of Soil pH at the field scale, has been made commercially available in the US. While driving over the field, Soil pH is measured on-the-go directly within the Soil by ion selective antimony electrodes. The aim of this study was to evaluate the Veris pH Manager™ under farming conditions in Germany. Sensor readings were compared with data obtained by standard protocols of Soil pH assessment. Experiments took place under different scenarios: (a) controlled tests in the lab, (b) semicontrolled test on transects in a stop-and-go mode, and (c) tests under practical conditions in the field with the sensor working in its typical on-the-go mode. Accuracy issues, problems, options, and potential benefits of the Veris pH Manager™ were addressed. The tests demonstrated a high degree of linearity between standard laboratory values and sensor readings. Under practical conditions in the field (scenario c), the measure of fit (r2) for the regression between the on-the-go measurements and the reference data was 0.71, 0.63, and 0.84, respectively. Field-specific calibration was necessary to reduce systematic errors. Accuracy of the on-the-go maps was considerably higher compared with the pH maps obtained by following the standard protocols, and the error in calculating lime requirements was reduced by about one half. However, the system showed some weaknesses due to blockage by residual straw and weed roots. If these problems were solved, the on-the-go sensor investigated here could be an efficient alternative to standard sampling protocols as a basis for liming in Germany.
Chuanfa Chen - One of the best experts on this subject based on the ideXlab platform.
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surface modelling of Soil pH
Geoderma, 2009Co-Authors: Zhengping Du, Yinjun Song, Chuanfa ChenAbstract:In addition to classical methods, namely kriging, Inverse Distance Weighting (IDW) and splines, which have been frequently used for interpolating the spatial patterns of Soil properties, a relatively more accurate surface modelling technique is being developed in recent years, namely high accuracy surface modelling (HASM). It has been used in the numerical tests, DEM construction and the interpolation of climate and ecosystem changes. In this paper, HASM was applied to interpolate Soil pH for assessing its feasibility of Soil property interpolation in a red Soil region of Jiangxi Province, China. Soil pH was measured on 150 samples of topSoil (0-20 cm) for the interpolation and comparing the performance of HASM, kriging. IDW and splines. The mean errors (MEs) of interpolations indicate little bias of interpolation for Soil pH by the four techniques. HASM has less mean absolute error (MAE) and root mean square error (RMSE) than kriging, IDW and splines. HASM is still the most accurate one when we use the mean rank and the standard deviation of the ranks to avoid the outlier effects in assessing the prediction performance of the four methods. Therefore, HASM can be considered as an alternative and accurate method for interpolating Soil properties. Further researches of HASM are needed to combine HASM with ancillary variables to improve the interpolation performance and develop a user-friendly algorithm that can be implemented in a GIS package. (C) 2009 Elsevier B.V. All rights reserved.
Robin Gebbers - One of the best experts on this subject based on the ideXlab platform.
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Soil pH mapping with an on the go sensor
Sensors, 2011Co-Authors: Michael Schirrmann, Robin Gebbers, Eckart Kramer, Jan SeidelAbstract:Soil pH is a key parameter for crop productivity, therefore, its spatial variation should be adequately addressed to improve precision management decisions. Recently, the Veris pH Manager™, a sensor for high-resolution mapping of Soil pH at the field scale, has been made commercially available in the US. While driving over the field, Soil pH is measured on-the-go directly within the Soil by ion selective antimony electrodes. The aim of this study was to evaluate the Veris pH Manager™ under farming conditions in Germany. Sensor readings were compared with data obtained by standard protocols of Soil pH assessment. Experiments took place under different scenarios: (a) controlled tests in the lab, (b) semicontrolled test on transects in a stop-and-go mode, and (c) tests under practical conditions in the field with the sensor working in its typical on-the-go mode. Accuracy issues, problems, options, and potential benefits of the Veris pH Manager™ were addressed. The tests demonstrated a high degree of linearity between standard laboratory values and sensor readings. Under practical conditions in the field (scenario c), the measure of fit (r2) for the regression between the on-the-go measurements and the reference data was 0.71, 0.63, and 0.84, respectively. Field-specific calibration was necessary to reduce systematic errors. Accuracy of the on-the-go maps was considerably higher compared with the pH maps obtained by following the standard protocols, and the error in calculating lime requirements was reduced by about one half. However, the system showed some weaknesses due to blockage by residual straw and weed roots. If these problems were solved, the on-the-go sensor investigated here could be an efficient alternative to standard sampling protocols as a basis for liming in Germany.
