[Near infrared spectral analysis and measuring system for primary nutrient of soil]

Soil is the foundation of agricultural production. Rapid analysis of soil nutrients, using near infrared spectral analysis technology, can guide process of agricultural production. Developing near-infrared measuring system with discrete wavelength will change the extensive operation situation of agricultural production. First, the spectra of 85 black soil samples of northeast China, collected by FOSS XDS near-infrared spectrometer were analyzed using the correlation spectra and successive projection algorithm. Then, the characteristic wavelengths of total nitrogen and organic matter were obtained. After that the authors collected the spectra of soil samples using the measuring system with high signal to noise ratio (SNR) that the authors developed. The calibration models for total nitrogen and organic matter were established. The root mean square error of prediction (RMSEP) of total nitrogen and organic matter is 0.019% and 0.36% respectively, and the correlation coefficient of prediction (R(P)) is 0.851 and 0.923, respectively. Experimental results indicate that the characteristic wavelengths for total nitrogen and organic matter can be obtained through the near infrared spectra analyses. The measuring system can be used for soil nutrient analysis and lays the foundation for the industrial applications.