Fig. 1. Output of DOM components fluorescent signatures from PARAFAC model and validation results of the components: Left (A); Right (B)
The A shows the five fluorescence components, including (a): C1 tryptophan-like, (b): C2 fulvic-like, (c): C3 microbial-humic-like, (d): C4 humic-like, (e): C5 tyrosine*like, outputted from PARAFAC model. The B shows the split-half verification results corresponding to the components; excitation (left) and emission (right) loading spectra were estimated from two random halves of data set (Split1-blue line and Split2-orange line), and the complete data set (black line)

Fig. 2. Differences in fluorescence properties between groups
Note: C1 tryptophan-like, C2 fulvic-like, C3 microbial-humic-like, C4 humic-like, C5 tyrosine-like Mcknight, BIX biological origin index; HIX humification index

Fig. 3. Principal coordinate axis analysis of fluorescent property

Fig. 4. Correlations between fluorescent property of DOM with peanut biomass and soil properties

Fig. 5. Variation partitioning analysis on the composition of DOM