摘要
在一定温度下磷酸盐和周边水体氧的同位素分馏仅受生物活动控制,因此磷酸盐氧同位素成为生态系统中磷源和磷循环研究的良好示踪剂。介绍了磷酸盐氧同位素研究应用的理论基础和近几年来针对土壤富含有机质,氧元素来源多样的特点发展起来的土壤磷酸盐氧同位素的分析和纯化方法,综述了磷酸盐氧同位素在土壤磷源示踪和磷循环应用研究中的初步进展,并提出目前研究存在的局限和对未来工作的展望。
Phosphorus is a nutrient essential to all living organisms in the soil. Researches have demonstrated that oxygen isotope in phosphate is an important tracer for source and cycling of the phosphate in the ecosystem. This type of researches in based theoretically on the hypothesis that under natural surface temperature and pH conditions, P-O bond in phosphate is quite stable and not likely to get hydrolyzed easily However, in the process of enzyme mediated biological ac- tivity, the P-O bond would break, leading to fractionation of oxygen isotopes, which means that oxygen isotope fractiona- tion in phosphate is primarily controlled by biological activity. As phosphate in soil is often very limited in natural abun- dance and a large quantity of organic matter exists in soil, how to remove the interference of oxygen from other sources in the soil is the key to determination of oxygen isotopes in phosphate that needs several rounds of enrichment, isolation and purification. This paper summarizes the theoretical basis and analytical technique, including methods for extraction and purification and instrumental analysis of soil inorganic P inthe study on oxygen isotopes in soil phosphate, reviews recent progresses in the study on application of phosphate oxygen isotopes as tracer ti determining source of the phosphate in soil and cycling of phosphate in the ecosystem, and puts forth methods for extraction of organic phosphate in soil and the use of 18O-labeled and enriched phosphate in the study, which will further help deepen the knowedge about phosphorus transport in soil.
出处
《土壤学报》
CAS
CSCD
北大核心
2015年第1期19-27,共9页
Acta Pedologica Sinica
基金
福建省自然科学基金项目(2011J05033)
国家自然科学基金项目(21207126)
中国科学院知识创新工程青年人才领域前沿项目(IUEQN-2012-02)资助
关键词
土壤磷酸盐
氧同位素组成
磷源
磷循环
Phosphate in soil
Oxygen isotope composition
Phosphate sources
Phosphorus cycling
