不同林龄茶园土壤和茶叶硒含量分布特征及其影响因素

Factors Affecting Selenium Contents in Soil and Tea Leaves at Different Planting Year Tea Trees

【目的】研究了不同林龄(1、5、10、15年)茶园土壤和茶叶硒含量分布特征,分析了不同林龄茶树林土壤和茶叶硒含量的影响因素。【方法】采取野外调查取样和室内分析。【结果】①茶树林冠幅、基茎、分枝数随生长年限的增加而增加,而茶树林密度随生长年限的增加而降低;②不同林龄茶树林土壤养分含量(有机碳、全氮、全磷、全钾、速效氮、速效磷和速效钾)总体上随着生长年限的增加呈先增加后降低趋势,在生长年限为10年时,土壤养分含量达到最大,生长年限超过10年以后,土壤养分含量则急剧降低,依次表现为10年生>15年生>5年生>1年生。③水浸出物、茶多酚、咖啡碱和游离氨基酸则急剧降低,依次表现为10年生>15年生>5年生>1年生。④土壤和茶叶全硒含量、全硒富集系数和有效全硒富集系数随着生长年限的增加呈先增加后降低趋势,在生长年限为10年时达到最大。⑤相关性分析表明土壤全硒含量与土壤养分呈显著正相关,而茶叶全硒和有效硒与土壤理化性质之间相关性未达到显著性水平(P>0.05)。【结论】不同林龄茶园土壤硒含量的主要影响因子是土壤有机碳(载荷系数为0.689)和全氮(载荷系数为0.702),不同林龄茶园茶叶硒含量的主要影响因子是水浸出物(载荷系数为0.623)和茶多酚(载荷系数为0.726)。

【Objective】This paper aimed to study the selenium contents in soil and tea leaves at different planting year tea trees(1a,5a,10a,15a).【Method】Field sample investigation and indoor analysis method were measured.【Result】(i)The crown,stem and branch of tea trees increased and tree density decreased with increasing planting age.(ii)Soil nutrients(Organic carbon,total nitrogen,total phosphorus,total potassium,available nitrogen,available phosphorus and available potassium)first increased and then decreased from 1 to 15 years of tea trees,which showed 10 a>15 a>5 a>1 a.(iii)Water extract,tea polyphenols,caffeine and free amino acids first increased and then decreased from 1 to 15 years of tea trees,which showed 10 a>15 a>5 a>1 a.(iv)Total selenium content,total selenium enrichment coefficient and effective total selenium enrichment coefficient in soil and tea first increased and then decreased from 1 to 15 years of tea trees,which showed 10 a>15 a>5 a>1 a.(v)Correlation analysis showed that the total selenium content in soil was significantly positively related with soil nutrient,and there was the correlation of the tea full selenium and effective selenium with soil physical and chemical properties but not significant(P>0.05).【Conclusion】The main influencing factors for soil selenium were organic carbon(load coefficient was 0.689)and total nitrogen(load coefficient was 0.702),and the main influencing factors for the selenium of leaves were the water extract of tea(load coefficient was 0.623)and tea polyphenols(load coefficient was 0.726).