为明确大气O3浓度升高对麦季各生育期不同土层中Zn生物有效性的影响，利用开顶式气室（ OTCs）设置正常大气和臭氧浓度升高（比周围大气高40 nmol／mol ）处理，土壤设置外源加入0 mg／kg、200 mg／kg、400 mg／kg Zn处理，在小麦苗期、分蘖期、拔节期、抽穗期和成熟期分别采集耕层0～5.0 cm、5.1～10.0 cm、10.1～15.0 cm各土层土样，同时利用BCR连续提取法和DTPA提取法评价盆栽小麦土壤Zn生物有效性。结果表明，大气臭氧浓度升高对整个耕层土壤（0～15.0 cm）Zn的有效性影响不显著；在成熟期显著增加了无外源Zn污染土壤0～5.0 cm和10.1～15.0 cm土层中Zn的有效性，其DTPA提取态Zn增幅分别为150％和241％，但在5.1～10.0 cm土层中DTPA提取态Zn显著降低42.4％；在小麦生育早期显著增大了外源加入400 mg／kg Zn污染土壤0～5.0 cm和10.1～15.0 cm土壤Zn的有效性。 BCR连续提取法与DTPA浸提法在衡量有效态Zn变化趋势上有相似的规律，但BCR连续提取法测定的有效态Zn数值大于DTPA浸提法，且土壤Zn含量低时差异显著。%The objective of this study was to clarify the changes of the bioavailability of zinc in the soil affected by atmospheric elevated ozone ( O3 ) during wheat season. Open top chamber ( OTCs) were used to set up normal atmospheric conditions and elevated atmospheric O3(40 nmol/mol higher). Three levels of exogenous zinc were applied (0 mg/kg,200 mg/kg, and 400 mg/kg) soil samples collected at 0-5 cm, 5. 1-10. 0 cm and 10. 1-15. 0 cm depth of topsoil at seedling, tillering, jointing, heading, and maturity respectively. The bioavailability of soil Zn was evaluated by the Community Bureau of Reference( BCR) sequential extraction and the DTPA extraction method. The elevated O3 level had no significant influence on the bioavailability of soil zinc in the topsoil. The zinc availabilities in non-polluted soil at 0-5. 0 cm and 10. 1-15. 0 cm depths were increased at maturity by elevated O3 level, with the increments of 150. 0% and 241. 0% using DTPA meth-od, while in the soil at 5. 1-10. 0 cm the zince availability was decreased by 42. 4%. Exogenous zinc at the application rate of 400 mg/kg boosted the soil zinc availabilities at 0-5. 0 cm and 10. 1-15. 0 cm depths. BCR method outperformed DTPA in describing the change of available zinc at low initial zinc concentration.
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