Soil Parameters Maps in Paddy Field Using the Real Time Soil Spectrophotometer

Abstract

Variability of soil parameters: moisture, soil organic matter (SOM), NO₃-N, pH and electric conductivity (EC) in a 0.5ha paddy field was confirmed using the soil reflectance collected by the real time soil spectrophotometer. Correlation analysis and stepwise multi linear regression analysis were performed after moving average smoothing, Kubelka-Munk transform and multiplicative scatter correction were applied to the soil reflectance. The results indicated that the soil reflectance was highly correlated to moisture and SOM content, and the 2^nd derivative reflectance gave better regression models. Block kriging with semivariance analysis made it easy to generate soil maps of the whole field, in which a similar variability in moisture and SOM was revealed.