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Online measurement of soil organic carbon as correlated with wheat normalised difference vegetation index in a vertisol field.

Tekin Y, Ulusoy Y, Tümsavaş Z, Mouazen AM - ScientificWorldJournal (2014)

Bottom Line: Calibration model of SOC in full cross-validation resulted in a good accuracy (R (2) = 0.75, root mean squares error of prediction (RMSEP) = 0.17%, and ratio of prediction deviation (RPD) = 1.81).The validation of the calibration model using laboratory spectra provided comparatively better prediction accuracy (R (2) = 0.70, RMSEP = 0.15%, and RPD = 1.78), as compared to the online measured spectra (R (2) = 0.60, RMSEP = 0.20%, and RPD = 1.41).Although visual similarity was clear, low similarity indicated by a low Kappa value of 0.259 was observed between the online vis-NIR predicted full-point (based on all points measured in the field, e.g., 6486 points) map of SOC and NDVI map.

View Article: PubMed Central - PubMed

Affiliation: Vocational School of Technical Science, Uludag University, 16059 Bursa, Turkey.

ABSTRACT
This study explores the potential of visible and near infrared (vis-NIR) spectroscopy for online measurement of soil organic carbon (SOC). It also attempts to explore correlations and similarities between the spatial distribution of SOC and normalized differential vegetation index (NDVI) of a wheat crop. The online measurement was carried out in a clay vertisol field covering 10 ha of area in Karacabey, Bursa, Turkey. Kappa statistics were carried out between different SOC and NDVI data to investigate potential similarities. Calibration model of SOC in full cross-validation resulted in a good accuracy (R (2) = 0.75, root mean squares error of prediction (RMSEP) = 0.17%, and ratio of prediction deviation (RPD) = 1.81). The validation of the calibration model using laboratory spectra provided comparatively better prediction accuracy (R (2) = 0.70, RMSEP = 0.15%, and RPD = 1.78), as compared to the online measured spectra (R (2) = 0.60, RMSEP = 0.20%, and RPD = 1.41). Although visual similarity was clear, low similarity indicated by a low Kappa value of 0.259 was observed between the online vis-NIR predicted full-point (based on all points measured in the field, e.g., 6486 points) map of SOC and NDVI map.

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Related in: MedlinePlus

Comparison maps of soil organic carbon (SOC) between laboratory measured (a), laboratory visible and near infrared (vis-NIR) predicted (b), and online vis-NIR predicted (c), based on the 25 samples of the independent validation set maps.
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Related In: Results  -  Collection


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fig6: Comparison maps of soil organic carbon (SOC) between laboratory measured (a), laboratory visible and near infrared (vis-NIR) predicted (b), and online vis-NIR predicted (c), based on the 25 samples of the independent validation set maps.

Mentions: Comparison maps between laboratory measured, laboratory vis-NIR predicted, and online vis-NIR predicted maps using the independent validation set of 25 samples show reasonable spatial similarity with high and low concentration zones of SOC distinguishable clearly. However, a visual comparison of these maps reveals presence of a better spatial similarity between the laboratory measurement (Figure 6(a)) and laboratory vis-NIR prediction (Figure 6(b)), as compared to online vis-NIR prediction map (Figure 6(c)).


Online measurement of soil organic carbon as correlated with wheat normalised difference vegetation index in a vertisol field.

Tekin Y, Ulusoy Y, Tümsavaş Z, Mouazen AM - ScientificWorldJournal (2014)

Comparison maps of soil organic carbon (SOC) between laboratory measured (a), laboratory visible and near infrared (vis-NIR) predicted (b), and online vis-NIR predicted (c), based on the 25 samples of the independent validation set maps.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4109388&req=5

fig6: Comparison maps of soil organic carbon (SOC) between laboratory measured (a), laboratory visible and near infrared (vis-NIR) predicted (b), and online vis-NIR predicted (c), based on the 25 samples of the independent validation set maps.
Mentions: Comparison maps between laboratory measured, laboratory vis-NIR predicted, and online vis-NIR predicted maps using the independent validation set of 25 samples show reasonable spatial similarity with high and low concentration zones of SOC distinguishable clearly. However, a visual comparison of these maps reveals presence of a better spatial similarity between the laboratory measurement (Figure 6(a)) and laboratory vis-NIR prediction (Figure 6(b)), as compared to online vis-NIR prediction map (Figure 6(c)).

Bottom Line: Calibration model of SOC in full cross-validation resulted in a good accuracy (R (2) = 0.75, root mean squares error of prediction (RMSEP) = 0.17%, and ratio of prediction deviation (RPD) = 1.81).The validation of the calibration model using laboratory spectra provided comparatively better prediction accuracy (R (2) = 0.70, RMSEP = 0.15%, and RPD = 1.78), as compared to the online measured spectra (R (2) = 0.60, RMSEP = 0.20%, and RPD = 1.41).Although visual similarity was clear, low similarity indicated by a low Kappa value of 0.259 was observed between the online vis-NIR predicted full-point (based on all points measured in the field, e.g., 6486 points) map of SOC and NDVI map.

View Article: PubMed Central - PubMed

Affiliation: Vocational School of Technical Science, Uludag University, 16059 Bursa, Turkey.

ABSTRACT
This study explores the potential of visible and near infrared (vis-NIR) spectroscopy for online measurement of soil organic carbon (SOC). It also attempts to explore correlations and similarities between the spatial distribution of SOC and normalized differential vegetation index (NDVI) of a wheat crop. The online measurement was carried out in a clay vertisol field covering 10 ha of area in Karacabey, Bursa, Turkey. Kappa statistics were carried out between different SOC and NDVI data to investigate potential similarities. Calibration model of SOC in full cross-validation resulted in a good accuracy (R (2) = 0.75, root mean squares error of prediction (RMSEP) = 0.17%, and ratio of prediction deviation (RPD) = 1.81). The validation of the calibration model using laboratory spectra provided comparatively better prediction accuracy (R (2) = 0.70, RMSEP = 0.15%, and RPD = 1.78), as compared to the online measured spectra (R (2) = 0.60, RMSEP = 0.20%, and RPD = 1.41). Although visual similarity was clear, low similarity indicated by a low Kappa value of 0.259 was observed between the online vis-NIR predicted full-point (based on all points measured in the field, e.g., 6486 points) map of SOC and NDVI map.

Show MeSH
Related in: MedlinePlus