亚热带土壤亚铁与厌氧反硝化  

Ferrous Iron Involved in Denitrification in Subtropical Soils Under Anaerobic Condition

作　　者：续勇波[1] 蔡祖聪[2] 

机构地区：[1]云南农业大学烟草学院,昆明650201 [2]南京师范大学地理科学学院,南京210097

出　　处：《土壤》2015年第1期63-67,共5页Soils

基　　金：国家自然科学基金项目(31101605;31260503);云南省自然科学基金项目(2010ZC083)资助

摘　　要：本文就亚热带土壤亚铁参与反硝化的可能性进行了探讨。研究结果表明:厌氧还原条件下加入KNO3的处理中,Fe2+浓度随培养时间延长而下降,且Fe2+浓度的降低和NO3–-N浓度的降低呈显著正相关。预培养结束后的亚铁浓度(In-Fe2+)和厌氧培养期间Fe2+浓度降低速率与反硝化势表征指标k、b、v7,以及与无定形铁氧化物(活性铁)含量的显著正相关性初步证明,活性铁通过不同价态铁离子(Fe2+和Fe3+)之间的转化,参与了反硝化的电子传递过程。当有机碳等电子供体受限时,Fe2+可作为电子供体参与反硝化还原NO3–-N。这一结果表明,NO3–-N作为电子受体参与厌氧条件下Fe2+氧化成Fe3+的反应可能在铁氧化物含量丰富的亚热带土壤中普遍存在。The possibility of ferrous iron involved in denitrification in subtropical soils was investigated. The results showed that in the treatment KNO3 added under anaerobic condition, the Fe2＋ concentration decreased with incubation time, and the decrease in Fe2＋ concentration was significantly positively correlated with the reduction of NO3-N content. There were significant positive correlations between the Fe2＋ concentration at the end of pre-incubation （In-Fe2＋）, or the decreasing rate of Fe2＋ concentration during the anaerobic incubation period and the indicators of denitrification capacity （k, b and VT）. The contents of amorphous Fe oxides （active iron） were also significantly positively correlated with ln-Fe2＋ and the decreasing rate of Fez＋ concentration. The correlation testified preliminarily that the active iron was involved in denitrification by the electron transfer between Fez＋ and Fe3＋. Fe2＋ could participate in NO3-N reduction during denitrification acted as electron donor when other electron donors such as organic carbon were restricted. The results also suggested that nitrate could also serve as an electron acceptor in the oxidation of Fe2＋ to Fe3＋ under anoxic conditions, indicating the reaction would probably universally exist in the subtropical soils which are abundant in iron oxides.

关 键 词：铁 厌氧培养 反硝化 氧化还原反应 

分 类 号：S153[农业科学—土壤学]