富炭硅肥对水稻土铁还原菌群落特征的影响

为了探究富炭硅肥施加处理对稻田土壤铁还原菌相对丰度、多样性及群落结构的影响，以福州平原稻田为研究对象，分别设置对照组及3种不同剂量（300，600和900kg/hm²）富炭硅肥施加处理组.研究结果表明：施加富炭硅肥有助于土壤铁还原菌的生长和繁殖，其中600kg/hm²施加处理对铁还原菌的生长影响最为显著（P<0.05）.由Shannon指数可知，3种施加处理均使晚稻拔节期土壤铁还原菌多样性有所下降，以300kg/hm²施加处理组多样性指数降低最为明显，较对照组降低了29.4%.在早、晚稻拔节期土壤中共鉴定出5个菌门，其中变形菌门（Proteobacteria）、拟杆菌门（Bacteroidetes）和厚壁菌门（Firmicutes）的占比之和平均高达95%以上，是稻田土壤中的优势菌门.施加富炭硅肥后，早稻拔节期土壤中拟杆菌属（Bacteroides）的相对丰度显著提高（P<0.05），而厌氧粘细菌属（Anaeromyxobacter）的相对丰度则有所降低.此外，环境因子与稻田土壤铁还原菌的相对丰度具有相关性，Desulfovibrio的相对丰度与土壤pH值呈显著正相关（P<0.05），Anaeromyxobacter的相对丰度与土壤温度（ST）呈显著正相关（P<0.05）.

Effects of carbon-enrich silicon fertilizer on the community characteristics of iron-reducing bacteria in paddy fields

In order to explore the relative abundance, diversity and community structure of iron-reducing bacteria (FeRB) in paddy fields of Fuzhou Plain, by setting up the control group and the treatment groups with three dosage levels (300, 600 and 900kg/hm²) of carbon-enrich silicon fertilizer (CESF). The results showed that the application of CESF facilitated the growth and reproduction of FeRB, among which 600kg/hm² treatment had the most significant impact on the growth of FeRB (P<0.05). According to the Shannon index, the diversity of FeRB was decreased by the three treatment groups during the jointing stage of late rice. The diversity index of the 300kg/hm² treatment group decreased most significantly, which was 29.4% lower than the control group. In the jointing stage of early and late rice, a total of 5 phyla have been identified in the soils. The total proportion of Proteobacteria, Bacteroidetes and Firmicutes was over 95% on average, and they were the dominant bacteria phyla in paddy fields. After application of CESF, the relative abundance of Bacteroides in the soil at early rice jointing stage was significantly increased (P<0.05), while that of Anaeromyxobacter was decreased. In addition, environmental factors were correlated with relative abundance of FeRB in the soils. The relative abundance of Desulfovibrio was significantly and positively correlated with soil pH (P<0.05). The relative abundance of Anaeromyxobacter was significantly and positively correlated with soil temperature (P<0.05). The above studies concluded that diversity and community structure of FeRB were significantly affected by CESF in paddy fields.