生物质炭和有机肥配施对水稻土溶解性有机质光谱学特征的影响

为探究生物质炭对水稻土壤溶解性有机质（DOM）的影响及其与有机肥配施的协同效应，通过5年连续定位试验，探讨了生物质炭施用5年后不同施肥处理：对照(CK)、生物质炭 (BC)、化肥(F)、生物质炭+化肥(F+BC)、化肥+有机肥（25%氮替代, MF）和化肥+生物质炭+有机肥（25%氮替代, MF+BC）对水稻产量和土壤pH、全氮、有效磷、速效钾、有机碳、易氧化有机碳（ROC）及溶解性有机碳的影响。采用紫外-可见光谱、荧光光谱结合平行因子分析方法对土壤中DOM的光谱特征和荧光组分进行表征，分析了DOM的紫外光吸收系数和紫外光斜率系数以及荧光指数、腐殖化指数、生物指数和富里酸、色氨酸、胡敏酸相对含量。结果表明：施用生物质炭和有机肥均能有效提高水稻产量，缓解土壤酸化，并且MF+BC处理水稻产量和土壤有效磷含量最高。水稻产量与DOM生物可利用性、芳香化程度、腐殖化程度、色氨酸组分含量和亲水性呈显著正相关(P＜0.05)。提高DOM生物可利用性和腐殖化程度均表现为有机肥大于生物质炭。生物质炭显著增加DOM富里酸和色氨酸组分含量，并且促进了水稻土中ROC向难氧化有机碳转化；而有机肥有效增加DOM富里酸、色氨酸、胡敏酸和ROC含量。生物质炭和有机肥协同配施对提升水稻产量及增加ROC、DOM富里酸和色氨酸含量、芳香化程度、腐殖化程度和生物可利用性方面具有交互作用。综上所述，在本研究条件下生物质炭配施有机肥在水稻增产和水稻土有机碳及DOM组分功能多样性提升方面具有长期效应。

Effects of Biochar and Organic Fertilizers Combined Application on Spectral Characteristics of Soil Dissolved Organic Matter in Paddy Soil

【Objective】This study aimed to investigate the long-term and synergistic effects of Biochar and organic fertilizer on dissolved organic matter (DOM) in paddy soil. 【Method】Several fertilization treatments were tested over five years, including a control (CK), biochar (BC), fertilizer (N), biochar+fertilizer (N+BC), manure+fertilizer (MF, 25% nitrogen replacement), and manure+fertilizer+biochar (MF+BC, 25% nitrogen substitution). The effects of these treatments on soil pH, total nitrogen, available phosphorus, accessible potassium, soil organic carbon (SOC), readily oxidizable organic carbon (ROC), and dissolved organic carbon were examined. The spectral properties and fluorescence components of DOM were characterized using the ultraviolet-visible spectrum (UV-Vis), fluorescence spectrum, and parallel factor analysis. Also, the specific UV absorbance, UV absorption slope rate, fluorescence index, biological index, humification index, and relative amounts of fulvic acid, tryptophan, and humic acid of the DOM were examined. 【Result】The results showed that by utilizing biochar and organic fertilizer, soil acidity could be decreased and rice productivity effectively increased. The MF+BC treatment had the highest rice productivity and soil available phosphorus of all the treatments. Significantly (P＜0.05) favorable correlations between rice yield and DOM""s bioavailability, aromatization, humification, tryptophan concentration, and hydrophilicity were found. The order of the degree of humification and bioavailability increase in DOM was manure > biochar. Furthermore, biochar significantly increased DOM, fulvic acid, and tryptophan components and promoted the conversion of ROC to dysoxidizable-organic carbon, whereas organic fertilizer increased ROC, fulvic acid, tryptophan, and humic acid components. The application of Biochar and organic fertilizer had an interaction effect on the increase of rice production, ROC, DOM, fulvic acid, tryptophan, aromatization, humification, and DOM bioavailability. 【Conclusion】Thus, the combined application of biochar and organic fertilizers increased rice yield while also enhancing the functional diversity of organic carbon and DOM components in paddy soil.