中文摘要：

通过添加不同浓度碳酸盐,探讨厌氧泥浆培养过程碳酸盐对6种水稻土Fe（Ⅲ）还原特征的影响。结果表明,添加碳酸盐可显著提高宝坻和东宁水稻土中Fe（Ⅲ）还原潜势及最大反应速率,降低最大反应速率所对应的时间;添加高质量摩尔浓度碳酸盐将显著降低上饶和汉中水稻土的Fe（Ⅲ）还原潜势和最大反应速率;不同质量摩尔浓度碳酸盐对强酸性的奉化水稻土中Fe（Ⅲ）还原潜势没有明显影响,但最大反应速率则表现为先增大后降低的趋势;对于强碱性的松原水稻土表现为Fe（Ⅲ）还原潜势降低,但最大反应速率增大。整体比较,添加碳酸盐对酸性水稻土中氧化铁还原的影响程度低于碱性水稻土。典范对应分析表明,添加碳酸盐增加有机质对Fe（Ⅲ）还原潜势的贡献,降低无定形氧化铁和游离氧化铁对最大反应速率的贡献。Fe（Ⅲ）还原潜势和最大反应速率与土壤有机质质量分数和培养体系pH有密切联系。

英文摘要：

Effects of inorganic carbon on iron cycle in paddy soils are not clear. Iron reduction charac ters in 6 paddy soils during the process of slurry anaerobic culture were studied by adding different concentrations of carbonate. The results showed that iron reduction potential and maximum reaction rates increased significantly in Baodi and Dongning paddy soils, but the time to maximum reaction rates decreased with adding carbonate. However, iron reduction potential and maximum reaction rates in Shangrao and Hanzhong paddy soils were decreased significantly when added in higher concentration of carbonate. Maximum reaction rates increased in lower concentration of carbonate but decreased in higher concentration of carbonate, though there was no significant effect on iron reduction potential in Fenghua strong acidic paddy soils. In comparison, iron reduction potential in strong alkaline paddy soil decreased while maximum reaction rates increased in Songyuan. As a whole, effects of carbonate on iron reduction in acidic paddy soils were lower than that in alkaline paddy soils. Canonical correspondence analysis showed that adding carbonate enhanced contribution of organic matters to iron reduction potential, but weakened contribution of amorphous and free iron to maximum reaction rates. Both iron reduction potential and maximum reaction rate had closed connections with soil organic matters and pH.