福建省典型茶园土壤硒含量及其影响因素研究

采集了福建省60份典型茶园表层土壤(0~20 cm),测定了土壤全硒和有效硒含量,分析了土壤类型、植茶年限和海拔对土壤硒及有效硒含量的影响,并探讨其受土壤理化性质的影响。结果表明,福建省茶园土壤全硒含量范围为0.22~2.20 mg·kg^-1,均值为0.73 mg·kg^-1,有86.67%的茶园土壤硒含量达到富硒土壤标准(>0.4 mg·kg^-1);茶园土壤有效硒含量为5.21~448.86 μg·kg^-1,均值为62.98 μg·kg^-1;土壤硒活化率为1.10%~31.64%,均值为8.76%,硒有效程度较低。砂砾岩和凝灰岩发育的茶园土壤硒和有效硒含量较高,紫色砂岩和河流冲积物发育的茶园土壤硒含量较低;山地草甸土茶园土壤全硒和有效硒含量最高,潮砂土和水稻土硒含量较低;成龄茶园和老茶园土壤全硒和有效硒含量较高,新垦茶园硒含量较低;中高海拔地区茶园土壤全硒及有效硒含量较高,低海拔地区茶园土壤硒含量较低。相关分析表明,茶园土壤硒及有效性主要受土壤有机质和全氮的影响,pH对有机质含量较低的红壤茶园和幼龄茶园有显著影响,有效磷对成龄茶园和中高海拔茶园有显著影响。总体而言,该区域茶园富硒土壤为发展天然富硒茶提供了物源保证,但硒有效程度不高,应针对不同类型茶园采取相应栽培措施(增施有机肥、改良剂和钙镁磷肥)来提高土壤有效硒。

Study on Soil Selenium Content and Its Influencing Factors in Typical Tea Garden of Fujian Province

A total of 60 samples of surface soils (0-20 cm) were collected from main tea producing areas of Fujian province to assess the total and available soil selenium. Their relations with soil physical and chemical properties were also discussed. The results show that content of total selenium in the surface soils ranged from 0.22 mg·kg^-1 to 2.20 mg·kg^-1 with an average of 0.73 mg·kg^-1, and 86.67% of the soils belonged to Se-rich soils. The ranges of available selenium in soil were from 5.21 to 448.86 μg·kg^-1, with a mean of 62.98 μg·kg^-1. The available rate of selenium ranged from 1.10% to 31.64%, with a mean of 8.76%. The total and available selenium contents in soils from glutenite and tuff were higher, and those in soils from purple sandstone and river alluvium were lower. For different soil types, alpine meadow soil showed the highest total and available selenium content, while moisture sand yand paddy soils were relatively lower. The total and available selenium contents in mature and old tea gardens were the highest, and the young tea garden was the lowest. The total and available selenium contents in the middle-high elevation tea garden were the highest, and the low elevation tea garden was the lowest. Selenium content in tea garden soil was significantly positively correlated with soil organic matter and total nitrogen contents. Whereas the soil pH also significantly affect the selenium content in red soil and young tea garden. And, the soil available phosphate was also a significant effect on selenium content in mature and middle-high elevation tea garden. In general, the Se-enriched soils in the tea gardens provided a source guarantee for the development of Se-enriched tea. However, the effectiveness of soil selenium was not high and should be adjusted in tea garden via different cultivation measures (additional application of organic fertilizers, ameliorant and calcium magnesium phosphate fertilizers) to increase availability selenium content.