O_3浓度升高对麦季土壤-植株系统中微量元素的影响

利用O3-FACE平台研究近地面臭氧浓度升高（目标值比周围大气高50%）对2009—2010年间麦季各生育期不同深度（0～5cm,5～10cm和10～15cm）耕层土壤微量元素有效性和成熟期地上部分微量元素累积量的影响。结果表明,近地层大气O3浓度增加提高了麦季耕层（0～15cm）土壤中有效性Fe、Mn含量,降低了有效性Cu、Zn含量,对Zn的减幅达27.3%（P〈0.05）;大气O3浓度升高对土壤5～10cm土层DTPA提取态Fe、Mn、Cu、Zn的影响最大;高O3浓度显著降低了5～10cm和10～15cm土壤DTPA-Zn含量（P〈0.05）。O3浓度升高降低了小麦成熟期生物量和微量元素累积量。对不同层次土壤有效态微量元素和成熟期微量元素累积量对O3浓度升高响应进行了分析,同时指出应从土壤性质和作物生长两个方面进一步研究全球大气环境变化对土壤有效态微量元素的影响机制。

Effect of O3 Enrichment on DTPA-extractable Microelements in Soil and Accumulation of Microelements of Mature Crops in the Wheat Season

Ozone Free-air Concentration Enrichmen（tO3-FACE）system was used in this study to investigate the effects of atmospheric elevated O3 on concentrations of DTPA-extractable microelements in soil and microelements accumulation of plant in the wheat season during 2009 to 2010.Concentrations of DTPA-extractable Fe,Mn,Cu,Zn at different soil depths（0～5 cm,5～10 cm and 10～15 cm）and microelement accumulation of plant at mature stage were determined under ambient and elevated（target at 50% above ambient）ozone concentration treatment.The results showed that elevated O3 increased the concentrations of DTPA-extractable Fe,Mn in soil at 0 ～15 cm depth with 11.7%,6.2%,and reduced the concentrations of DTPA-extractable Cu,Zn in soil at 0～15 cm depth with 3.0%,27.3%（P0.05）,respectively.Elevated O3 significantly increased the concentrations of DTPA-extractable Fe,Mn,Cu and Zn in soil at 5～10 cm depth.Elevated O3 significantly reduced the concentration of DTPA-extractable Zn in 5～10 cm and 10～15 cm soil（P0.05）,and decreased accumulation of dry matter and microelements in above-ground of wheat at maturity stage.This article analyzed the reasons of changes of microelements in soil and wheat plant under elevated O3,and pointed out that in order to understand the impact mechanism of elevated O3 on concentrations of DTPA-extractable microelements in soil,soil properties and plant growth,together with the microelement status at different soil depths should be considered.