黑土水溶性有机碳对有机物料还田的响应

【目的】探究不同有机物料还田措施下黑土水溶性有机碳含量及组成的变化特征,为黑土区土壤肥力提升提供科学依据。【方法】以黑龙江省克山县定位7年的有机物料还田小区为研究对象,采用常规测定及荧光分析方法,以单施化肥处理为对照,对配施有机肥、生物炭、秸秆3种有机物料处理下土壤水溶性有机碳含量及结构进行分析。【结果】与单施化肥相比,配施有机物料使土壤水溶性有机碳含量提升9.65%—20.30%,土壤总有机碳含量提升6.63%—14.86%。各有机物料还田处理下土壤水溶性有机碳中类酪氨酸蛋白质物质、类色氨酸蛋白质物质减少。有机肥施入使水溶性有机碳中溶解性微生物代谢产物增加,使富里酸类物质、腐殖酸类物质增加并使二者结构简化;秸秆、生物炭使土壤水溶性有机碳中富里酸类物质结构简化;生物炭的添加使土壤水溶性有机碳中腐殖酸类物质复杂化。【结论】有机肥、生物炭、秸秆3种有机物料不同程度上提升了土壤水溶性有机碳中各组分含量、增强土壤微生物分解代谢、使水溶性有机碳中结构相对简单的富里酸组分含量增加、结构简化,其中以有机肥效果最佳。

The Response of Water-Soluble Organic Carbon to Organic Material Applications in Black Soil

【Objective】The change characteristics of water soluble organic carbon (WSOC) content and components in black soil with the addition of different organic materials were explored to provide a scientific basis for soil fertility improvement methods in black soil area.【Method】This study was based on experimental plots of returning organic materials to the field in Keshan County, Heilongjiang Province, and the experiment has lasted for seven years. The content and structure of WSOC treated with organic fertilizer, biochar, straw and single fertilizer treatment (CK) was analyzed by routine determination and fluorescence analysis.【Result】Compared with the single application of chemical fertilizer, the content of soil water-soluble organic carbon increased by 9.65%-20.30% and soil organic carbon increased by 6.63%-14.86% under the application of organic materials. The contents of tyrosine-like protein and tryptophan-like protein in WSOC decreased under the treatment of organic materials. The application of organic fertilizer increased the contents of metabolites of soluble microorganisms in WSOC, increased the contents of fulvic acid and humic acid in WSOC, and simplified their structures. Straw and biochar simplified the structure of fulvic acids and biochar complicates the structure of humic acids in WSOC.【Conclusion】Organic fertilizer, biochar and straw improved the content of soil water-soluble organic carbon, enhanced the decomposition and metabolism of soil microorganisms, increased the content and simplified the structure of fulvic acid component in water-soluble organic carbon. Organic fertilizer had the best effect.