不同供氮水平对施用玉米秸秆后黑土氨基糖转化的影响  

Effects of nitrogen supply level on microbial transformation of amino sugar in a mollisol amended with maize straw

作　　者：丁雪丽[1,2] 何红波[1] 白震[1,2] 解宏图[1] 张彬[1,2] 张旭东[1,3] 

机构地区：[1]中国科学院沈阳应用生态研究所陆地生态过程重点实验室,沈阳110016 [2]中国科学院研究生院,北京100039 [3]沈阳农田生态系统国家野外科学观测研究站,沈阳110016

出　　处：《应用生态学报》2009年第9期2207-2213,共7页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金重点项目(40535028);国家科技支撑计划项目(2007BAD89B02);中国科学院沈阳应用生态研究所海外留学基金项目(07HWLX11S4)资助

摘　　要：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.A 38-week laboratory incubation test at 25℃ was conducted to examine the effects of different inorganic N supply level （0, 60. 3, 167.2, and 701.9 mg N·kg^-1 soil, noted as No, Nlow, Nmid, and Nhig, respectively） on the microbial transformation of amino sugar in a mollisol amended with maize straw. Comparing with the control, the amendment of maize straw promoted the microbial synthesis of amino sugar, and at the early period of incubation, the total amount of soil amino sugar increased with increasing inorganic N supply, being significantly higher in treatments Nmid and Nhig than in treatments NO and Nlow. With prolonged incubation time, the total amount of soil amino sugar decreased, and the decrement was higher in treatments NO and Nlow than in treatments Nmid and Nhig. Different inorganic N supply level also had different effects on the dynamics of various amino sugars. Muramic acid exclusively originated from bacteria was more easily to be affected by the inorganic N supply, compared with the glucosamine from fungal cell wall residues. For the amendment of higher C/N maize straw, a sufficient N supply would be necessary for the promotion of the accumulation and transformation of soil amino sugar. Soil N deficiency would restrict the growth of soil microbes, weaken the microbial synthesis of amino sugar, and decrease the captured N in microbial biomass, being not beneficial to the soil N accumulation.

关 键 词：氨基糖 转化 供氮水平 玉米秸秆 土壤 

分 类 号：S158[农业科学—土壤学]