Feasibility of near-infrared spectroscopic rapid detection method for the water content of vermiculite substrates in desert facility agriculture

The rapid determination of the water content of vermiculite substrates can promote the efficiency of desert agricultural facilities. The near-infrared spectroscopy protocol developed in this research could be applied to rapidly and quantitatively detect the water content of vermiculite substrates commonly used in desert agricultural facilities. Two different feature extraction algorithms were used to screen characteristic variables. The partial least-squares and multiple linear regression methods were used to establish a relationship model. The multiple linear regression model with feature variables extracted by a successive projection algorithm based on Savitzky-Golay smoothing preprocessing had the best performance, with a prediction-to-deviation ratio of 11.75. The results of this study provide a feasible method for rapidly detecting the moisture content of vermiculite substrates.