近年来生物炭被广泛地用于土壤改良和污染土壤修复，然而长期大量施用生物炭可能改变土壤中微量元素的赋存状态，进而影响土壤的可持续生产力，但相关研究仍很缺乏。本项目拟借助BET、FTIR、XRD、SEM-EDS、XPS等表征手段，研究生物炭的孔径结构、表面性质、化学特性与微量元素的空间固持关系及对溶液中微量元素的吸附与解吸；研究不同生物炭与土壤对微量元素的竞争性吸附，生物炭对土壤有机无机复合体、理化性质和生物学特性的影响及其与微量元素形态的关系；通过盆栽试验和梯度扩散薄膜技术（DGT），明确生物炭对土壤微量元素形态的影响。从生物炭自身吸附、与土壤的竞争吸附、以及形成的有机无机复合体、团聚体和微生物群落结构变化对微量元素形态的调控机制等多角度综合分析，阐明生物炭对土壤微量元素形态转化和生物有效性的影响机制。以期加深理解生物炭对土壤元素循环过程的影响，为指导生物炭的合理农业利用提供科学依据。

Biochar has been widely used for soil improvement and remediation of contaminated soil. However，Long-term application of biochar to soil will have the influence on the forms and bioavailability of trace elements in soil, and then may affect the soil sustainable productivity. Study on effect of biochar application on the forms and cycle of elements in soil has important scientific significance. The research about soil microelement’s cycle after application of biochar to soil is relatively lacking. The objective of this project is to study influence mechanism of application of biochar on the bio-availability of trace elements soil. The trace elements in the plant, the form and distribution of trace elements in soil, and physicochemical and biochemical properties of soil at different stages of plant under the rice and wheat seasons will be determined. With BET, FTIR, XRD, SEM-EDS, XPS and the diffusion gradient thin film technology (DGT), the adsorption mechanism of different components of biochar to the trace elements in solution will be studied. The competitive adsorption of soil and biochar to trace elements in soil; the influence of biochar on soil aggregate composition, organic mineral complex components and microbial community structure and the relationship with forms and bioavailability of trace elements in soil, and soil chemical properties and absorption of rice and wheat will be investigated. The internal mechanism between these processes will be explored. Understanding this mechanism is the important foundation to assess accurately influence of biochar application on soil sustainable productivity, to improve the corresponding knowledge of soil and plant nutrition, and to provide the scientific basis for guiding the application of biochar in agriculture.