The Influence of Aerated Irrigation on the Evolution of Dissolved Organic Matter Based on Three-Dimensional Fluorescence Spectrum

In order to unravel the effect of aerated irrigation on soil dissolved organic matter (DOM) fluorescence characteristics, and humification degree, a randomized block experiment was conducted with three factors two-level design, i.e., two rates (0.6 1.0 times crop evaporation pan coefficient, W1 W2), nitrogen application (225 300 kg hm−2, N1 N2), aeration (15% 0% in control treatment, A1 A0). Fluorescence regional integration (FRI) correlation analysis methods were used investigate evolution characteristics DOM spectrum. Under conventional subsurface irrigation, components dominated by humic acid-like substances, fulvic tryptophan-like proteins, supplemented tyrosine-like proteins microbial metabolites. Soil could promote consumption under low accelerate high rates. The index AI treatments varied from 8.47 9.94 during maturity growth stage pepper, averagely increased 31.59% compared non-aeration treatment. To sum up, can depletion small molecular nutrient turnover accumulation big proteins.