| 摘要: |
| 【目的】研究施氮对油松林土壤有机碳，全氮，可溶性糖及微生物生物量碳、氮含量的影响,为了解油松林土壤有机质的内在转化过程提供理论依据。 【方法】2015-2017年，在山西省太岳山自然保护区进行氮肥试验，于每年5月向油松林地表施用硝酸铵(NH4NO3)，使样地的施氮水平分别为0（对照），5，10，20，40 g/（m2·年），依次简称N0、N5、N10、N20、N40，测定不同处理表层（0～10 cm）和底层（10～20 cm）土壤有机碳，全氮，可溶性糖，微生物生物量碳、氮含量，微生物活性以及代谢熵，并分析了油松林土壤可溶性糖与有机碳，全氮以及微生物生物量碳、氮含量，微生物活性以及代谢熵的相关性。【结果】表层（0~10 cm）土壤中，与对照（N0）相比，N5、N10处理对土壤有机质含量均无显著影响，而N20、N40处理显著降低了土壤有机质含量；底层（10~20 cm）土壤中，各施氮处理土壤有机质含量无显著变化。表层（0~10 cm）土壤中，与对照（N0）相比，N5、N10、N20、N40处理表层土壤可溶性糖含量分别上升了81.67%，100.13%，127.73%，171.21%，土壤可溶性糖含量随着施氮量的增加而增大（P<0.05）；底层（10~20 cm）土壤中，只有N40处理土壤可溶性糖含量与对照有显著差异，其余处理与对照均无显著差异。表层（0~10 cm）土壤中，与对照（N0）相比，N5、N10处理对土壤微生物生物量碳、氮含量无显著影响，而N20、N40处理会显著降低土壤微生物生物量碳、氮含量；底层（10~20 cm）土壤中，各施氮处理土壤微生物生物量碳、氮含量与对照相比均无显著变化。表层（0~10 cm）土壤中，与对照（N0）相比，N5、N10处理土壤微生物活性、代谢熵无显著变化，而N20、N40处理土壤微生物活性、代谢熵则显著上升；底层（10~20 cm）土壤中，各施氮处理与对照的土壤微生物活性、代谢熵差异均不显著。相关性分析表明，土壤可溶性糖含量与土壤有机碳，全氮，微生物生物量碳、氮含量以及微生物活性,代谢熵都呈正相关关系。【结论】施氮能显著提高太岳山油松林表层土壤可溶性糖含量。低氮处理对表层土壤微生物活性及微生物生物量碳、氮含量无显著影响，高氮处理能显著提高土壤微生物活性，显著减少土壤微生物生物量碳、氮含量。 |
| 关键词: 油松林 施氮处理 土壤微生物 土壤微生物生物量 土壤可溶性糖 |
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| 基金项目:“十三五”国家重点研发项目“经营措施对人工林地力的影响机制”（2016YFD0600205） |
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| Effects of nitrogen application on soil soluble sugar and microbial biomass in a Pinus tabulaeformis forest |
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CHEN Yan,YU Hui,ZHANG Huan,et al
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| Abstract: |
| 【Objective】The effects of nitrogen application on contents of soil organic carbon,total nitrogen and soluble sugar and carbon and nitrogen contents in soil microbial biomass in a Pinus tabulaeformis forest were studied.To provide a theoretical basis for understanding the intrinsic transformation process of soil organic matter in Pinus tabulaeformis forest.【Methods】The nitrogen addition experiment was conducted at the Taiyue Mountain Nature Reserve from 2015 to 2017.Ammonium nitrate (NH4NO3) was applied to a Pinus tabulaeformis forest in each May at levels of 0,5,10,20 and 40 g/(m2·year),abbreviated as N0,N5,N10,N20 and N40.The contents of soil organic carbon,total nitrogen and soluble sugar and microbial biomass carbon and nitrogen contents,microbial activity and metabolic entropy were measured and the interactions were analyzed.【Results】In the surface layer (0-10 cm),N5,N10 treatment had no significant change in soil organic mather,N20 and N40 treatments significantly reduced soil organic matter content compared with the control (N0).In the bottom layer (10-20 cm),there was no significant change in soil organic matter content.In the surface layer,soluble sugar contents in N5,N10,N20 and N40 were increased by 81.67%,100.13%,127.73% and 171.21%,respectively （P<0.05）.In the bottom layer,only N40 treatment significantly influenced soluble sugar content.In the surface layer,N5,N10 treatment had no significant change in soil microbial biomass carbon and nitrogen content,N20 and N40 treatments significantly reduced soil microbial biomass carbon and nitrogen contents.In the bottom layer,there was no significant change in soil microbial biomass carbon and nitrogen contents.In the surface layer,the soil microbial activity and metabolic entropy of N5 and N10 treatments did not change significantly,while those of N20 and N40 treatments increased significantly.In the bottom layer,there was no significant change in soil microbial activity and metabolic entropy.Correlation analysis showed that soil soluble sugar content was positively correlated with soil organic carbon,total nitrogen,microbial biomass carbon,nitrogen content,microbial activity and metabolic entropy.【Conclusion】Nitrogen application can significantly improve soluble sugar content in surface soil of Pinus tabulaeformis forest in Taiyue Mountain.Low nitrogen treatments (N5 and N10) had no significant effect on microbial activity and microbial biomass carbon and nitrogen contents in surface soil.High nitrogen treatments (N20 and N40) can significantly increase microbial activity and significantly reduce microbial biomass carbon and nitrogen contents. |
| Key words: Pinus tabulaeformis forest nitrogen application soil microbial soil microbial biomass soil soluble sugar |
