This paper presents the possibilities of extracting total potassium concentration in topsoil from Visible-near-infrared
(VNIR) spectra and reflectance of image data. Stepwise multiple linear regression (SMLR) and partial least-square
regression (PLSR) were used to select wavelengths which were highly correlated with the concentration of potassium.
For spectral measurements (from 400nm to 2480nm, at 2 nm increments) and chemical analyses, 70 topsoil (0~20 cm)
samples were collected in Tianjin City, North of China. Three methodologies of the reflectance spectra of topsoil
samples were employed: derivative reflectance spectra (FDR), inverse-log spectra (log (1/R)) and band depth (Depth).
According to the root mean square error of prediction (RMSEP), the best model was picked up. The optimal experiential
model (R=0.73, RMSEP=1.33) was achieved by PLSR method with parameter- log (1/R). Based on these credible
results, space distribution map of soil potassium concentration of Tianjin was drawn by ETM+ image. The coefficient
showed that the first and second bands of ETM were important for soil potassium concentration prediction. The
potassium concentration of seaboard is higher than that of inland area. Good prediction performance indicates that VNIR
spectra are potentially useful for rapid estimation of potassium concentration in topsoil, and inverse-log spectra (log
(1/R)) are the best parameter for prediction. Even the image data can be used for soil potassium concentration extraction
and the influences of the atmosphere and proper pre-processing are very important to prediction precision.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.