摘要
【目的】解析土壤pH值与土壤氮以及CH_(4)排放速率与土壤碳氮含量间的相互关系,为明确碳氮转化及温室气体排放规律、优化温带森林暗棕壤的水分管理提供依据。【方法】以温带森林暗棕壤为研究对象,采用室内培养法,设置水分条件为土壤饱和持水量(WHC)的40%、60%、90%,通过向温带暗棕壤中添加两种不同性质的氨基酸,探讨其对土壤碳氮含量及CH_(4)排放的潜在影响,运用Pearson相关分析法分析土壤碳氮含量、pH值及CH_(4)排放速率间的相关性。【结果】(1)氨基酸处理显著增加了土壤可溶性有机碳(DOC)含量、铵态氮(NH_(4)^(+)-N)含量及CH_(4)排放速率。亮氨酸处理使DOC、NH_(4)^(+)-N含量分别升高21.39%、45.10%,CH_(4)排放速率较CK升高3.20倍,甲硫氨基酸使DOC、NH_(4)^(+)-N含量分别升高21.39%、72.71%,CH_(4)排放速率较CK升高7.00倍;(2)不同氨基酸对土壤硝态氮(NO_(3)^(-)-N)含量的影响存在差异。亮氨酸处理使土壤NO_(3)^(-)-N含量升高了8.41%,但其对于土壤硝化作用的影响可能存在滞后性,而甲硫氨基酸能够显著抑制土壤硝化作用,NO_(3)^(-)-N含量显著降低了37.90%;(3)土壤不同水分条件对土壤DOC、NH_(4)^(+)-N、NO_(3)^(-)-N含量及CH_(4)排放速率均存在显著影响。90%WHC使DOC含量升高11.95%~19.91%,使NH_(4)^(+)-N升高19.83%~35.46%,使NO_(3)^(-)-N降低10.05%~23.79%,使CH_(4)排放速率升高至另外两种水分条件的1.48~2.06倍。60%WHC条件使NH_(4)^(+)-N升高13.05%,使NO_(3)^(-)-N含量升高24.62%。60%WHC可能是温带暗棕壤硝化作用的最适含水量,90%WHC条件有利于DOC积累,同时对NO_(3)^(-)-N的产生存在明显抑制作用;(4)土壤pH与N H4+-N含量呈极显著正相关,与NO_(3)^(-)-N含量呈正相关。CH_(4)排放速率与NO_(3)^(-)-N含量呈极显著负相关,与NH_(4)^(+)-N含量呈负相关,与DOC含量呈极显著正相关。【结论】不同性质氨基酸添加在温带森林暗棕壤碳氮含量及CH_(4)排放中发挥的作用不尽相同。一定范围内,土壤水分含量的升高有利于土壤NH_(4)^(+)-N、NO_(3)^(-)-N、DOC的积累及CH_(4)的排放,但土壤高含水量条件对NO_(3)^(-)-N的产生具有抑制作用。因此,在研究温带森林暗棕壤碳含量、CH_(4)排放及氮转化机制时,建议关注不同氨基酸的差异性作用,同时考虑水分的变化。
[Objective] To clarify the response of carbon and nitrogen content and CH_(4) emission to different soil moisture conditions and the additions of amino acid in the dark brown soil of temperate forests,this study analyzed the relationship between soil pH and nitrogen,CH_(4) emission rate and soil carbon and nitrogen content,to assist related research on water management,carbon and nitrogen transformation,and greenhouse gas emission in temperate forest dark brown soil.[Method] In this study,an indoor soil incubation was conducted with 40%,60%,and 90% of the soil water holding capacity (WHC).Additionally,the potential effects of adding two amino acids on soil carbon and nitrogen content and CH_(4) emissions were explored.The Pearson correlation analysis was used to analyze the correlation between soil carbon and nitrogen content,pH and methane emission rate.[Result] (1) Amino acid addition increased soil dissolved organic carbon (DOC) content,and meanwhile significantly increasedNH_(4)^(+)-N content and CH_(4) emission rate.Leucine treatment increased the contents of DOC and NH_(4)^(+)-N by 21.39%-45.10%,respectively,and the CH_(4) emission rate was 3.20 times higher than that of CK,methionine treatment increased the contents of DOC and NH_(4)^(+)-N by 21.39%-72.71%,respectively.and the CH_(4) emission rate was 7.00 times higher than that of CK.(2) The influence of different amino acids on soilNO_(3)^(-)-N content was different.Leucine treatment increased NO_(3)^(-)-N content in soil by 8.41%,but its effect on nitrification in soil may have a lag,while methionine can significantly inhibit nitrification in soil,and NO_(3)^(-)-N content was significantly reduced by 37.90%.(3) Different soil moisture conditions had significant effects on soil DOC,NH_(4)^(+)-N,NO_(3)^(-)-N and CH_(4) emission rates.90%WHC increased DOC content by 11.95%-19.91%,NH_(4)^(+)-N by 19.83%-35.46%,NO_(3)^(-)-N by 10.05%-23.79%,and CH_(4) emission rate increased to 1.48-2.06 times of the other two water conditions.Under 60%WHC condition,NH_(4)^(+)-N increased by 13.05%,NO_(3)^(-)-N content increased by 24.62%.60%WHC may be the optimum water content for nitrification in temperate dark brown soil.The 90%WHC condition was conducive to the accumulation of DOC,and had an obvious inhibitory effect onNO3--N production.(4) Soil pH was significantly positively correlated withNH_(4)^(+)-N content,positively correlated with NO_(3)^(-)-N content.The CH_(4) emission rate was significantly negatively correlated with NO_(3)^(-)-N content and NH_(4)^(+)-N content,and significantly positively correlated with DOC content.[Conclusion] Addition of different types of amino acids plays different roles on the carbon and nitrogen content and CH_(4) emissions of dark brown soil in temperate forests.Within a certain range,the increase of soil moisture content is beneficial to soilNH_(4)^(+)-N,NO_(3)^(-)-N,DOC accumulation and CH_(4) emission,but high soil moisture content inhibits the production of NO_(3)^(-)-N.Therefore,the role of amino acids and changes in moisture should be considered when studying carbon content,CH_(4) emissions and nitrogen transformation mechanisms in temperate forest dark brown soils.
作者
李颖
郭亚芬
崔晓阳
Li Ying;Guo Yafen;Cui Xiaoyang(School of Forestry,Northeast Forestry University,Harbin 150040,Heilongjiang,China)
出处
《北京林业大学学报》
CAS
CSCD
北大核心
2024年第5期103-113,共11页
Journal of Beijing Forestry University
基金
国家自然科学基金项目(31370617)。
关键词
土壤水分
氨基酸态氮
碳氮含量
甲烷
温带暗棕壤
soil moisture
amino acid nitrogen
carbon and nitrogen content
methane
temperate dark brown soil