Supplementary material from "Analysing the effect of paddy rice variety on fluorescence characteristics for nitrogen application monitoring"

Paddy rice is one of the most important cereal crops worldwide; it is a significant target to accurately monitor its growth status and photosynthetic efficiency. Nitrogen (N) level is a key factor closely related to crop growth. In this study, laser-induced fluorescence (LIF) technology combined with multi-variate analysis was applied to investigate the effect of paddy rice variety on the N fertilizer levels monitoring. Principal components analysis was conducted to extract the variables of the main fluorescence characteristics to identify N levels. Experimental results demonstrated that no nitrogen fertilizer can be completely identified for each paddy rice variety. In addition, other N levels can also be well classified based on fluorescence characteristics. Then, the relationship between the fluorescence ratio (F735/F685 : F735, and F685 denote the fluorescence intensity at 735 nm, and 685 nm, respectively) and leaf N content of different paddy rice varieties was also discussed. Experimental results revealed that LIF technology is an effective method to monitor N fertilizer and leaf biochemical components of paddy rice.