Research of the influences of utilization of sediment and exogenous materials on the changes of SDOM and WSOC of soil

Abstract

As mankind pays attention to environmental protection and reuse of resources, more and more exogenous materials are being utilized for soil improvement, such as straw, sediment, etc. However, further research is needed on the mechanism of how sediments and other exogenous materials change soil properties. In this study, the changes of soil water soluble organic carbon (WSOC) and soil dissolved organic matter (SDOM) in the process of resource utilization of sediment and other exogenous materials were investigated. Different exogenous substances such as river sediment (RS), lake sediments (LS), straw (SS), algae (AS), Myriophyllum verticillatum L. submerged plants (MS) and livestock manure (FS) were added to the soil, and fluorescence spectroscopy combined with parallel factor analysis was used to explore the characteristics of WSOC changes and SDOM sources in the treated soil. The results showed that the SDOM fluorescence intensity changes show the total fluorescence intensity of the three groups of SS, FS, and MS was significantly higher (P < 0.01) than the control group. After 50 days of culture, the content of WSOC in the 6 groups was: MS (72.2 mg/kg) > LS (58.2 mg/kg) > FS (45.6 mg/kg) > RS (44.8 mg/kg) > AS (41.4 mg/kg) > SS (39.4 mg/kg) > CK (32.7 mg/kg). the MS group increased the most, reaching a percentage of 220%. The parallel factor analysis of SDOM three-dimensional fluorescence spectra showed that SDOM in soil mainly contains three components, groups contain protein-like, humus-like and tyrosine-like amino acids. In the initial stage, protein-like substances are the main components, and after 50 days, humus-like substances become the main components of SDOM in each treated soil. Among them, the FS group has the highest humus-like content. According to the fluorescence intensity, the SS, FS and MS groups have significant effects on increasing the content of soil water-soluble organic matter, and the SS group has the strongest effect. In summary, sediment and straw, algae, Myriophyllum verticillatum L., livestock manure can change the content of SDOM and WSOC in the soil can change the content of SDOM and WSOC in the soil, enhance the degree of soil vitality, increase the vitality of the soil, and improve the structure, composition, and quality of the soil. This research provided theoretical guidance and technical support for the resource utilization of sediment, straw, algae, submerged plants and livestock manure.