Open AccessThis article is
- freely available
Soil pH Mapping with an On-The-Go Sensor
Leibniz-Institute for Agricultural Engineering, Department of Engineering for Crop Production, Max-Eyth-Allee 100, D-14469 Potsdam, Germany
HNEE School for Sustainable Development Eberswalde, Friedrich-Ebert-Str. 28, D-16225 Eberswalde, Germany
Technical University of Dresden, D-01062 Dresden, Germany
* Author to whom correspondence should be addressed.
Received: 11 November 2010; in revised form: 23 December 2010 / Accepted: 29 December 2010 / Published: 7 January 2011
Abstract: 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 ManagerTM, 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 ManagerTM 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 ManagerTM 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.
Keywords: precision agriculture; soil sensors; digital soil mapping; soil sampling; pH; antimony electrode; Veris pH ManagerTM
Citations to this Article
Cite This Article
MDPI and ACS Style
Schirrmann, M.; Gebbers, R.; Kramer, E.; Seidel, J. Soil pH Mapping with an On-The-Go Sensor. Sensors 2011, 11, 573-598.
Schirrmann M, Gebbers R, Kramer E, Seidel J. Soil pH Mapping with an On-The-Go Sensor. Sensors. 2011; 11(1):573-598.
Schirrmann, Michael; Gebbers, Robin; Kramer, Eckart; Seidel, Jan. 2011. "Soil pH Mapping with an On-The-Go Sensor." Sensors 11, no. 1: 573-598.