氨基酸添加对亚热带森林红壤氮素转化的影响

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 氨基酸添加对亚热带森林红壤氮素转化的影响 DOI: 10.5846/stxb201405110957 作者: 作者单位: 湿润亚热带生态地理过程省部共建教育部重点实验室,湿润亚热带生态地理过程省部共建教育部重点实验室,湿润亚热带生态地理过程省部共建教育部重点实验室,湿润亚热带生态地理过程省部共建教育部重点实验室,湿润亚热带生态地理过程省部共建教育部重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目(40901115,41271282,31070549,31170578);教育部创新团队项目(IRT0960);福建省高校杰出青年科研人才培育计划(JA12058)和福建师范大学优秀青年骨干教师培养基金资助(fjsdjk2012069) Effects of amino acid additions on nitrogen transformation in subtropical forest soil Author: Affiliation: Key Laboratory of Humid Subtropical Eco-geographical Process of the Ministry of Education,Fujian Normal University,Key Laboratory of Humid Subtropical Eco-geographical Process of the Ministry of Education,Fujian Normal University,Key Laboratory of Humid Subtropical Eco-geographical Process of the Ministry of Education,Fujian Normal University,Key Laboratory of Humid Subtropical Eco-geographical Process of the Ministry of Education,Fujian Normal University,Key Laboratory of Humid Subtropical Eco-geographical Process of the Ministry of Education,Fujian Normal University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为探究氨基酸氮形态对亚热带土壤氮素含量及转化的影响,选择建瓯市万木林保护区的山地红壤为对象,采用室内培养实验法,通过设计60%和90% WHC两种土壤含水量并添加不同性质氨基酸,测定了土壤中铵态氮、硝态氮、可溶性有机氮的含量和氧化亚氮的释放量,分析了可溶性有机碳、土壤pH值的大小变化及其与氮素的相互关系。结果表明:与对照处理相比,氨基酸添加显著增加了土壤NH4+-N含量并使土壤pH值升高,且在一定程度上解除了高含水量(90% WHC)对NH4+-N产生的抑制,其中甲硫氨基酸的效果最为明显。酸性、碱性、中性氨基酸对土壤NO3--N含量和N2O释放影响不显著,但甲硫氨基酸可显著抑制土壤硝化从而导致NH4+-N的积累,并在培养前期抑制土壤N2O产生而在培养后期促进N2O释放,总体上促进N2O释放。60% WHC的氨基酸添加处理较90% WHC条件下降低土壤可溶性有机氮的幅度更大。氨基酸对土壤氮素转化的影响与带电性关系较小,而可能与其分解产物密切相关。可见,不同性质氨基酸处理对森林土壤氮素含量及转化存在不同程度的影响,且甲硫氨基酸对土壤氮素转化的影响机理值得深入研究。 Abstract:Research on the nitrogen cycle of forest soils has traditionally focused on the mechanisms regulating the turnover of inorganic N. However, the key role of organic N in soil nitrogen transformation tends to be overlooked. Over recent decades, researchers have assessed the relative importance of organic N on the nutritional requirements of plants in forest ecosystems. Most studies have revealed that soil amino acids are important sources of organic N in forest ecosystems. Although the fluxes of organic N in forest ecosystems have been studied in detail, we have a poor understanding about the role of amino acids in soil nitrogen transformation in the subtropical region of China. In this study, subtropical broad-leaved forest soil was collected from Wan Mulin Natural Reserve located at Fujian Province, southeast China. We selected four types of amino acids, including L-Glutamic acid, L-Lysine, L-Alanine, and L-Methionine as the study materials, which represented acidic, basic, neutral, and sulfur amino acids, respectively. Soils were incubated for 0, 2, 8, 12, 16, and 36 days in the laboratory after adding 0 and 40 mg N /kg amino acid. Soil moisture was maintained at 60% WHC (water-holding capacity) or 90% WHC. Ammonium N, nitrate N, soluble organic N, nitrous oxide, soil pH, and soluble organic C content were determined. Data were subjected to analysis of variance (ANOVA) with the SPSS version 18.0, and significant differences between treatments were compared by the LSD test at P < 0.05.The results showed that soil NH4+-N content significantly increased with the addition of amino acids, with the repression of NH4+-N production under high soil moisture content conditions (90% WHC) being relieved to some extent. Soil pH was increased by the addition of amino acids, and was closely correlated with soil NH4+-N and NO3--N. These results support the finding that an increase in soil pH may promote N mineralization in acidic forest soils. Acidic, basic, and neutral amino acids increased NH4+-N production in soil, but had little or no influence on NO3--N production and nitrous oxide emission. Soil nitrification was significantly inhibited by the addition of methionine, resulting in the accumulation of NH4+-N. Nitrous oxide emission from soil as a whole increased with the addition of methionine. The decrease in SON under the amino acid treatments was more evident under 60% WHC than 90% WHC conditions. The turnover of amino acids in forest soil is very rapid, with NH4+-N being the major N form in soil. Nitrogen transformation in forest soil is probably related to the decomposed products of amino acid mineralization, rather than the charge of amino acids. These findings indicate that nitrogen transformation varies with amino acid type, and that the mechanism inhibiting methionine during nitrification needs further research. In conclusion, amino acids might represent the intermediate products between organic nitrogen and mineral nitrogen, regulating nitrogen transformation in forest soils. 参考文献 相似文献 引证文献