Abstract:
This study is aimed at developing a non-destructive method for determining organic matter mineralization using
FT-NIR (Fourier Transform-Near Infrared) spectroscopy. Soils with two different textures were mixed with olive
solid waste (OSW), OSW composts and nitrogen, phosphorus and potassium (NPK) fertilizer. Samples have
been incubated at 25 oC for 9 months. After this period, some chemical and physical analyses were performed on
the samples using standard methods. Also reflectance spectra of the same samples were acquired right after the
standard measurements using FT-NIR spectroscopy. Calibration models between the standard measurements and
the spectral measurements performed on samples were established applying Partial Least Squares (PLS) method.
Promising N prediction was obtained for the compost added soil group (R2=0.62 and RMSECV=0.05) and good
N prediction was performed for the control soil group (0.93 and RMSECV=0.01). C was predicted successfully
for almost all of the data groups. Prediction of C for the data group that included all the soil groups was
performed with a coefficient of determination of 0.88 (RMSECV=0.27) in validation. C was predicted with the
coefficient of determination of 0.93 (RMSECV=0.23) for the compost added soil group. It was shown with this
study that NIR spectroscopy has the potential of sensing soil contents non-destructively.
