茶树品种对亚热带茶园土壤可溶性有机氮组成的影响

Effects of Tea Genotypes on Soil Soluble Organic Nitrogen Compositions in Subtropical Tea Plantations

为探讨茶树品种对茶园土壤可溶性有机氮(SON)组成的影响,以福建省中亚热带相同成土母质、地形和土壤类型的两种相邻的不同品种(黄金桂和福云6号)茶园为研究对象,采用TOC-TN分析、离子自动分析、氨基酸自动分析、气相色谱分析和核磁共振分析等技术,分析了不同茶树品种茶园表层(0~15 cm)土壤SON含量和组成特点及其差异。结果表明:黄金桂和福云6号表层土壤氨基酸含量分别占SON总量的37.24%和30.71%,供试茶园土壤SON组成均以非氨基酸的SON占优势,但黄金桂表层土壤氨基酸含量极显著高于福云6号;两种茶园表层土壤氨基酸均以中性氨基酸占优势,但黄金桂表层土壤中性氨基酸和含硫氨基酸含量分别显著和极显著高于福云6号;两种茶园表层土壤氨基酸种类组成相同,但黄金桂表层土壤的脯氨酸、苯丙氨酸、组氨酸、异亮氨酸、亮氨酸、丙氨酸、甘氨酸和缬氨酸含量比福云6号高52.93%~100.00%。研究表明茶树品种对茶园土壤SON组成具有显著影响,应关注茶树品种对占优势的非氨基酸SON组成的影响及其在茶园生态系统中的环境效应研究。

To explore the effects of tea genotypes on soil soluble organic nitrogen(SON)compositions, two adjacent tea plantations grown with different tea genotypes(Huangjingui and Fuyun 6)with the same parent material(tuff residual deposits), soil type(Alliti-Udic Fer-rosols), and landform(hilly slopes facing east)in mid-subtropics in Fujian were selected. Topsoil samples(0~15 cm)at upper, middle and lower positions of the slope in each tea plantation were collected in summer. The compositions and their concentrations of SON were analyzed using TOC-TN analyzer, Quickchem Automated Ion Analyzer, Automated Amino Acid Analyzer, Gas chromatograph and NMR Spectroscopy. Results showed that amino acids in topsoils of Huangjingui and Fuyun 6 plantations were 37.24% and 30.71% of total SON, respectively. Non-amino acids were the main SON fractions in two tea plantations. The content of total amino acids in Huangjingui topsoils was significantly higher than that in Fuyun 6 soils. Neutral amino acids were the dominant fraction of amino acids in both Huangjingui and Fuyun 6 plantations, accounting for 85.20% and 80.54% of the total amino acids, respectively. Neutral and sulfur amino acids in Huangjingui topsoils were significantly higher than those in Fuyun 6. The compositions of amino acids in both tea plantations were the same, but the concentrations of proline, phenylalanine, histidine, isoleucine, leucine, alanine, glycine and valine were 52.93% ~100.00% higher in Huangjingui topsoils than in Fuyun 6. These findings indicated that tea genotype greatly influenced compositions of SON in tea plantation soil and non-amino acids were the dominant fraction of SON. Therefore, it is important to reveal the effects of tea genotypes on non-amino acid components of SON and their environmental implications in tea ecosystems.