旱作褐土中氧化铁的厌氧还原与光合型亚铁氧化特征  

ANAEROBIC REDOX OF IRON OXIDES AND PHOTOSYNTHETIC OXIDATION OF FERROUS IRON IN UPLAND CINNAMON SOILS

作　　者：孙丽蓉[1] 王旭刚[1] 徐晓峰[1] 郭大勇[1] 

机构地区：[1]河南科技大学农学院,河南洛阳471003

出　　处：《土壤学报》2015年第6期1291-1300,共10页Acta Pedologica Sinica

基　　金：国家自然科学基金项目(41101215;U1504402);河南省科技攻关项目(11210211007)资助

摘　　要：土壤中铁的氧还过程与碳氮转化及自净能力关系密切，已还原亚铁的氧化受土壤性质的影响。采用室内恒温培养试验研究了旱作褐土中铁还原氧化过程、及其与水溶性碳、NO3-、SO42-的关系。结果表明旱作褐土中铁氧化物在厌氧光照条件下可先被还原后被再次氧化，其再氧化量介于1．46～3．00mgg-1之间，平均2．09mgg-1；再氧化速率常数介于0．23—0．80d-1之间，平均0．48d-1。再氧化量与土壤无定形铁、水溶性硫酸盐含量、阳离子交换量显著负相关，与土壤总氮、总磷显著正相关；再氧化速率常数与土壤有机碳显著负相关，与黏粒含量极显著正相关。厌氧光照培养可使旱作褐土水溶性无机碳平均降低52．74％，水溶性No；降低92．15％，水溶性SO42-增加55．38％。研究结果为深入理解旱作土壤潜在的微生物铁循环转化方式提供理论支持。Iron redox cycle is an important microbial process of the degradation of organic matter in anaerobic soil and sediment environment, and it is closely related to transformation of carbon and nitrogen and soil self-purification capacity. As Fe （ 11 ） produced anaerobically by dissimilatory iron reduction process could be oxidized by nitrate-reducing/iron-oxidizing bacteria, anoxygenic photosynthetic bacteria or oxygen produced by oxygenic photosynthetic bacteria in wetland soil anaerobically. Furthermore, risk of emission of greenhouse gases, such as C02 and biological availability of heavy metals decreases in the process at the same time. Whether oxidation of ferrous generated by dissimilatory iron reduction would occurs or not depends on soil properties, and ferrous oxidation characteristics, including capacity and rate constant are governed by soil pH and contents of water, nitrate, inorganic carbon and other co-substrates. Though upland cinnamon soils belong to oxisol, dissimilatory iron reduction of iron oxide may occur in the semi-luvisol cinnamon soils with adequate water content under non-illuminated incubation as the preliminary study shows, whether the Fe （ 11 ） produced anaerobically under non illuminated incubation could be re-oxidized in upland cinnamon soils under illumination incubation is not still clear and neither, are characteristics of the re-oxidation in these soils, not to mention relationship between oxidation characteristics and soil properties. To learn further in-depth about potential microbial iron redox cycle in upland soils, oxidation of ferrous generated by iron reduction, and relationship between ferrous oxidation in upland soils under illuminated incubation and soil properties, soil samples collected from upland farmlands at 7 different locations, and form nearby paddy fields, in which ferrous oxidation occurs under illumination anaerobically, were both prepared into slurry and then put under illuminated anaerobic incubation, to study characteristics of the anaerobic redox of

关 键 词：铁氧化物 厌氧还原氧化 旱作褐土 碳素转化 光照 

分 类 号：S153.4[农业科学—土壤学]