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采用室内恒温(25℃)培养方法,设置4个氮素添加水平(0、60.3、167.2、701.9mgN.kg-1,依次标记为N0、Nlow、Nmid、Nhig),培养38周,研究不同无机氮素添加水平对施入玉米秸秆黑土的氨基糖转化的影响.结果表明:与对照样品相比,添加秸秆可显著促进氨基糖的微生物合成与积累,且在培养前期氨基糖的总量随着无机氮素添加水平的增加而增加,Nmid和Nhig处理氨基糖积累量显著高于Nlow和N0处理;随着培养时间的延长氨基糖总量有所下降,Nlow和N0处理的下降幅度高于Nmid和Nhig处理.不同无机氮素供应水平对各氨基单糖的影响也有所不同,以胞壁酸为代表的细菌细胞壁物质比真菌细胞壁残留物如氨基葡萄糖更易受到土壤碳氮供给的影响,但真菌细胞壁物质对土壤有机质的截获和稳定作用大于细菌.说明对于C/N较大的玉米秸秆,土壤中无机氮素的供给对氨基糖在土壤中的积累转化有明显影响,氮素缺乏会抑制微生物生长,使氨基糖的合成作用减弱,在微生物体中截获的氮源减少,不利于土壤氮素的积累.
Four nitrogen addition levels (0, 60.3, 167.2, 701.9 mgN.kg-1, followed by N0, Nlow, Nmid and Nhig) were set up at room temperature (25 ℃) The results showed that: Compared with the control, the addition of straw can significantly promote the microbial synthesis and accumulation of amino sugar, and the total amount of amino sugar in the early stage of culture with the increase of The accumulation of N-glycosidase and Nhig was significantly higher than that of Nlow and N0 treatments when inorganic nitrogen was added. The total amount of amino-sugars decreased with the prolongation of culture time, and Nlow and N0 decreased more than Nmid And Nhig.The effects of different inorganic nitrogen supply levels on each amino-monosaccharide were also different. Bacterial cell wall material represented by muramic acid was more affected by soil carbon and nitrogen supply than fungal cell wall residues such as glucosamine, but fungi The cell wall material intercepted and stabilized the soil organic matter more than the bacteria, indicating that for the C / N larger corn stover, the supply of inorganic nitrogen in soil had a significant effect on the accumulation and transformation of amino sugars in the soil Nitrogen deficiency can inhibit the growth of microorganisms, the synthesis of amino sugar weakened, reducing intercepted in microorganisms in nitrogen, is not conducive to the accumulation of nitrogen in the soil.