The continuous cropping obstacle caused by the differential changes in beneficial and pathogenic bacteria in the rhizosphere mediated by root exudates is the main factor restricting the development of Salvia miltiorrhiza cultivation, Propose a method based on infrared spectroscopy technology combined with two-dimensional correlation spectroscopy to quickly detect the composition and content changes of root exudates of Salvia miltiorrhiza. The spectra of 7 kinds of Salvia miltiorrhiza soil samples in the same arca (not planted with Salvia miltiorrhizae), 1 year of rotation (19-ED, 23-ED), 2 years of rotation (23-One), 3 years of rotation (23-Two), 5 years of rotation (19-Five), and Salvia miltiorrhiza (19-ING) were collected, and the characteristics of the extraction were analyzed. The composition of soil compounds was analyzed. The results showed that the infrared spectral peaks and peak shapes of salvia miltiorrhiza cultivated at different intervals were the same. The main characteristic absorption peaks were around 3 622, 3 380,1 638, 995, 777, 693, 524 and 463 cm(-1), respectively, to characterize the functional groups of phenolic hydroxy -OH, carbonyl C=O, methylene, benzene ring absorption substitution, cyclic ketones and other substances in phenolic acids. The absorbance of the soil with 1 year of rotation was the strongest at cach characteristic peak, indicating that the autotoxic substances such as phenolic acids and esters continued to accumulate during the planting process. The position, number, and color of the absorption peaks were different in the hands 3750 similar to 3600, 2170 similar to 2145, 2060 similar to 2030, and 530 similar to 585 cm(-1), which clearly characterized the differences in functional groups. This indicates that the combination of infrared and 2D correlation spectroscopy can rapidly detect and monitor organic compounds in soil, and provide a theoretical basis for exploring the formation and reduction mechanisms of continuous cropping obstacles in Salvia miltiorrhiza.
