Next Article in Journal
Digital Video Broadcast-Terrestrial (DVB-T) Single Frequency Networks Positioning in Dynamic Scenarios
Next Article in Special Issue
Rapid Online Analysis of Local Feature Detectors and Their Complementarity
Previous Article in Journal
Nano-Molar Deltamethrin Sensor Based on Electrical Impedance of PAH/PAZO Layer-by-Layer Sensing Films
Previous Article in Special Issue
In-Plane Resonant Nano-Electro-Mechanical Sensors: A Comprehensive Study on Design, Fabrication and Characterization Challenges
Sensors 2013, 13(8), 10177-10190; doi:10.3390/s130810177
Article

Potential of On-Line Visible and Near Infrared Spectroscopy for Measurement of pH for Deriving Variable Rate Lime Recommendations

1,* , 2
 and
2
1 Vocational School of Technical Sciences, Uludag University, Bursa 16059, Turkey 2 Environmental Science and Technology Department, Cranfield University, Bedfordshire, MK43 0AL, UK
* Author to whom correspondence should be addressed.
Received: 31 May 2013 / Revised: 18 July 2013 / Accepted: 31 July 2013 / Published: 8 August 2013
(This article belongs to the Special Issue State-of-the-Art Sensors Technology in the UK 2013)
View Full-Text   |   Download PDF [584 KB, 21 June 2014; original version 21 June 2014]   |  

Abstract

This paper aims at exploring the potential of visible and near infrared (vis-NIR) spectroscopy for on-line measurement of soil pH, with the intention to produce variable rate lime recommendation maps. An on-line vis-NIR soil sensor set up to a frame was used in this study. Lime application maps, based on pH predicted by vis-NIR techniques, were compared with maps based on traditional lab-measured pH. The validation of the calibration model using off-line spectra provided excellent prediction accuracy of pH (R2 = 0.85, RMSEP = 0.18 and RPD = 2.52), as compared to very good accuracy obtained with the on-line measured spectra (R2 = 0.81, RMSEP = 0.20 and RPD = 2.14). On-line predicted pH of all points (e.g., 2,160) resulted in the largest overall field virtual lime requirement (1.404 t), as compared to those obtained with 16 validation points off-line prediction (0.28 t), on-line prediction (0.14 t) and laboratory reference measurement (0.48 t). The conclusion is that the vis-NIR spectroscopy can be successfully used for the prediction of soil pH and for deriving lime recommendations. The advantage of the on-line sensor over sampling with limited number of samples is that more detailed information about pH can be obtained, which is the reason for a higher but precise calculated lime recommendation rate.
Keywords: on-line soil sensor; vis-NIR spectroscopy; soil pH; lime recommendation map on-line soil sensor; vis-NIR spectroscopy; soil pH; lime recommendation map
This is an open access article distributed under the Creative Commons Attribution License (CC BY 3.0).
SciFeed

Share & Cite This Article

Further Mendeley | CiteULike
Export to BibTeX |
EndNote |
RIS
MDPI and ACS Style

Tekin, Y.; Kuang, B.; Mouazen, A.M. Potential of On-Line Visible and Near Infrared Spectroscopy for Measurement of pH for Deriving Variable Rate Lime Recommendations. Sensors 2013, 13, 10177-10190.

View more citation formats

Related Articles

Article Metrics

For more information on the journal, click here

Comments

[Return to top]
Sensors EISSN 1424-8220 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert