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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

Q-Q plots between laboratory measured (92 samples) soil organic carbon (SOC) versus normalized difference vegetation index (NDVI) (a) and online vis-NIR predicted (6486 points) versus NDVI (b).
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fig9: Q-Q plots between laboratory measured (92 samples) soil organic carbon (SOC) versus normalized difference vegetation index (NDVI) (a) and online vis-NIR predicted (6486 points) versus NDVI (b).

Mentions: The Q-Q plot of laboratory measured (92 samples) SOC versus NDVI (Figure 9(a)) shows staircase pattern of the distribution, which means that some values are discrete from the normal distribution. However, the Q-Q plot of NDVI and online full-point SOC map (Figure 9(b)) show a straight, smooth line, confirming visual similarities to be well represented.


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)

Q-Q plots between laboratory measured (92 samples) soil organic carbon (SOC) versus normalized difference vegetation index (NDVI) (a) and online vis-NIR predicted (6486 points) versus NDVI (b).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig9: Q-Q plots between laboratory measured (92 samples) soil organic carbon (SOC) versus normalized difference vegetation index (NDVI) (a) and online vis-NIR predicted (6486 points) versus NDVI (b).
Mentions: The Q-Q plot of laboratory measured (92 samples) SOC versus NDVI (Figure 9(a)) shows staircase pattern of the distribution, which means that some values are discrete from the normal distribution. However, the Q-Q plot of NDVI and online full-point SOC map (Figure 9(b)) show a straight, smooth line, confirming visual similarities to be well represented.

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