南京林业大学学报(自然科学版) ›› 2019, Vol. 43 ›› Issue (02): 1-6.doi: 10.3969/j.issn.1000-2006.201803022

• 研究论文 • 上一篇    下一篇

生物炭对杨树人工林土壤微生物生物量碳、氮、磷及其化学计量特征的影响

王国兵1, 王 瑞1, 徐 瑾1, 曹国华2, 阮宏华1   

  1. (1.南京林业大学,南方现代林业协同创新中心,南京林业大学生物与环境学院,江苏 南京 210037; 2.江苏省东台林场,江苏 东台 224200)
  • 出版日期:2019-03-30 发布日期:2019-03-30
  • 基金资助:
    收稿日期:2018-03-14 修回日期:2018-10-25
    基金项目:国家重点研发计划(2016YFD0600204); 江苏省高等学校自然科学研究重大项目(18KJA220001); 江苏高校优势学科建设工程资助项目(PAPD)。
    第一作者:王国兵(wangguobing81@aliyun.com),副教授,博士,ORCID(0000-0001-8362-9186)。

Effects of biochar application on microbial biomass C, N, P and stoichiometry characteristics of poplar plantation soil

WANG Guobing1, WANG Rui1, XU Jin1, CAO Guohua2, RUAN Honghua1   

  1. (1.Co-Innovation Center for the Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China; 2.Dongtai Forest Farm of Jiangsu Province, Dongtai 224200, China)
  • Online:2019-03-30 Published:2019-03-30

摘要: 【目的】揭示林分尺度下添加生物炭对土壤微生物生物量碳(SMBC)、土壤微生物生物量氮(SMBN)、土壤微生物生物量磷(SMBP)含量及其化学计量特征的影响,深入了解生物炭对杨树人工林土壤微生物群落结构与功能的影响,系统阐明生物炭调控人工林C、N、P生物地球化学循环的土壤微生物学机理,为在平原地区人工林生态系统中安全推广生物炭固碳增汇技术提供理论依据。【方法】以江苏省东台林场的杨树人工林为对象,设置生物炭添加量低(T1,40 t/hm2)、中(T2,80 t/hm2)、高(T3,120 t/hm2)3种处理及对照(不添加CK),测定SMBC、SMBN、SMBP含量及其化学计量特征(土壤微生物生物量碳、氮、磷含量比,即m(SMBC)/m(SMBN)、m(SMBC)/m(SMBP)、m(SMBN)/m(SMBP),文后简写为SMBC/SMBN、SMBC/SMBP、SMBN/SMBP)在不同处理间的差异,及其与土壤理化性质之间的关系。【结果】①与对照样地相比,3种生物炭添加处理均提高了SMBC、SMBN和SMBP含量。T1、T2、T3处理样地SMBC含量分别为对照样地的1.08、1.15、1.19倍; SMBN含量分别为对照样地的1.12、1.24、1.34倍; SMBP含量分别为对照样地的1.11、1.26、1.41倍; ②T1处理样地的SMBC/SMBN、SMBC/SMBP、SMBN/SMBP分别为15.7、85.0、5.4,T2处理样地的分别为15.1、78.6、5.2,T3处理样地的分别为14.3、73.3、5.1。与对照相比,3种生物炭添加处理均显著降低了SMBC/SMBN和SMBC/SMBP,且不同处理间差异显著(P<0.05),但仅T2、T3处理显著降低了SMBN/SMBP(P<0.05); ③SMBC、SMBN、SMBP含量均具有显著的季节变异,其中在植物休眠季节(2014年12月及2015年3月),SMBC、SMBN及SMBP的含量均维持在较高水平,而在植物生长的旺盛季节(2015年7月及2015年10月),其含量下降至较低水平,但SMBC/SMBN、SMBC/SMBP、SMBN/SMBP的季节变化与此完全相反; ④添加生物炭提高了土壤可溶性有机碳、硝态氮、速效磷、全氮和总有机碳含量,增加了土壤pH和含水率,但是降低了土壤密度和铵态氮含量; ⑤相关性分析表明,SMBC含量与土壤可溶性有机碳(DOC)、pH、含水率(SMC)、硝态氮(NO-3-N)和速效磷(AP)呈极显著正相关关系(P<0.01),与铵态氮(NH+4-N)呈极显著负相关关系(P<0.01),而与土壤密度、全氮(TN)和总有机碳(TOC)相关性不显著(P≥0.05); SMBN与SMBP的含量表现较为一致,均与DOC、pH、SMC、NO-3-N、AP、TN呈极显著正相关关系(P<0.01),与NH+4-N呈极显著负相关关系(P<0.01),而与土壤密度和TOC相关性不显著(P≥0.05)。【结论】添加生物炭能够显著提升SMBC、SMBN、SMBP含量,并有效降低SMBC/SMBN、SMBC/SMBP和SMBN/SMBP,有利于促进土壤微生物对N、P养分的固持与周转,进而改善土壤对N、P养分的供应。研究还发现,研究区杨树人工林生长可能存在N、P养分限制现象。

Abstract: 【Objective】This study aimed to reveal the effects of biochar application on soil microbial biomass C, N and P and its stoichiometry characteristics under a poplar plantation. In addition, we aimed to thoroughly understand the effects of biochar application on the structure and function of the soil microbial community and to systematically elucidate the soil microbiological mechanism behind biochar regulation of the biogeochemical cycle of C, N and P in poplar plantations. Ultimately, results of this study will provide important information for safely using biochar application as a carbon sequestration technology in plantation ecosystems. 【Method】Soil microbial biomass C, N, P(i.e. SMBC, SMBN and SMBP)and physicochemical properties(such as soil total organic carbon, total nitrogen, soluble organic carbon, nitrate nitrogen, ammonium nitrogen, available phosphorus, soil density, pH and moisture content)were examined in a poplar plantation in the Dongtai Forest Farm of Jiangsu Province. Four different treatments were used in this study: low biochar addition(T1, 40 t/hm2), middle biochar addition(T2, 80 t/hm2), high biochar addition(T3, 120 t/hm2), and no biochar addition(Control). 【Result】The SMBC, SMBN and SMBP all increased in the three biochar addition treatments relative to the control. SMBC increased by 687.2, 727.0 and 752.6 mg/kg in T1, T2 and T3 treatments, respectively, which was 1.08, 1.15 and 1.19 times higher than that in the control. SMBN increased by 44.1, 48.7 and 52.9 mg/kg in T1, T2 and T3 treatments, respectively, which was 1.12, 1.24, and 1.34 times greater than that in the control. SMBP increased by 8.2, 9.3 and 10.4 mg/kg in T1, T2 and T3 treatments, respectively, which was 1.11, 1.26 and 1.41 times greater than that in the control. SMBC/SMBN, SMBC/SMBP and SMBN/SMBP ratios in T1 were 15.7, 85.0 and 5.4, respectively. SMBC/SMBN, SMBC/SMBP and SMBN/SMBP ratios in T2 were 15.1, 78.6 and 5.2, respectively. SMBC/SMBN, SMBC/SMBP and SMBN/SMBP ratios in T3 were 14.3, 73.3 and 5.1, respectively. Both SMBC/SMBN and SMBC/SMBP ratios were significantly reduced in the three biochar addition treatments and significant differences were observed among treatments(P<0.05), but SMBN/SMBP ratio was only significantly reduced in T2 and T3(P<0.05). SMBC, SMBN, SMBP showed significant seasonal variation. C, N and P levels were higher in plant dormancy season(December 2014 and March 2015)and lower in the vigorous growing season(July 2015 and October 2015). However, seasonal variation of SMBC/SMBN, SMBC/SMBP and SMBN/SMBP ratios showed opposite trends. Biochar addition increased the contents of soluble organic carbon(DOC), nitrate nitrogen(NO-3-N), available phosphorus(AP), total nitrogen(TN), and total organic carbon(TOC). Biochar addition also increased soil pH and soil moisture content(SMC)and reduced soil density and ammonium nitrogen(NH+4-N). Correlation analysis showed that SMBC had a highly significant positive correlation with soil DOC, pH, SMC, NO-3-N and AP, while it had a highly significant negative correlation with NH+4-N(P<0.01). No significant correlation was observed for soil density, TN or TOC(P≥0.05). SMBN and SMBP had highly significant positive correlations with DOC, pH, SMC, NO-3-N, AP and TN and highly significant negative correlations with NH+4-N(P<0.01). No significant correlations were observed for soil density or TOC(P≥0.05). 【Conclusion】Our results provide preliminary evidence that biochar application is useful for promoting soil N and P and supporting poplar growth due to the increase in SMBC, SMBN, SMBP and its optimized stoichiometry characteristics. Growth may be limited by N and P in poplar plantations in this region.

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