A New Approach to Detect Soil Nutrient Content Based on NIR Spectroscopy Technique

The objective of this research was to evaluate the prediction ability of NIR to soil nutrient content. A total of 165 soil samples were obtained from the field and analyzed their spectra features. 135 samples spectra were used during the calibration and cross-validation stage, 30 samples spectra were used to predict N, P, K and OM concentration. NIR spectra and constituents were related using partial least square regression (PLSR) technique. The r between measured and predicted values of N and OM, were 0.92 and 0.93 respectively, demonstrated that NIRS have potential to predict accurately this constituents in this soil, not being this way in the prediction of P and K with r, 0.48 and 0.68 respectively, demonstrated a poorly for P and a less successfully for K prediction. The result also shows that NIR could be a good tool to be combined with precision farming application