摘要：以不同灌溉水位、施肥类型和施肥量水稻土壤（高水位化肥、低水位化肥、高水位常量有机肥、低水位常量有机肥、高水位高量有机肥及低水位高量有机肥）为研究对象，研究不同灌溉水位、施肥类型和施肥量对水稻土壤氨氧化细菌（Ammonia oxidizing bacteria，AOB）数量及硝化势（Nitrification potential, NP）的影响。结果表明，供试土壤pH均呈中性偏酸（pH5.84~6.48）。采用最大或然计数（MPN）法对土壤氨氧化细菌进行计数，发现在不同灌溉水位处理中，土壤氨氧化细菌数量存在显著差异（n=3，p<0.05），高水位高量有机肥和低水位化肥处理土壤AOB数量较多。低水位化肥处理土壤硝化势显著较高、硝化能力也较其他处理土壤强，但是其它土壤硝化势之间并无显著差异。氨氧化古菌（Ammonia-oxidizing archaea，AOA）富集结果显示，在实验室条件下可以富集AOA。

关键词：水稻土壤，氨氧化细菌，氨氧化古菌，硝化势

Abstract:In this study, effect of different irrigation water level, fertilizer types and dosage on the amount of Ammonia-oxidizing bacteria (AOB) and Nitrification potential (NP) in rice soil sampled from Hunan Province was studied using different treatments soils (HNPK，LNPK，HNOM，LNOM，HHOM and LHOM）as research object. The range of soil pH tested was from 5.84 to 6.48 . The amount of AOB was counted by the Most Probable Number (MPN) method, and the results showed that the amount of AOB were  significantly different between soil treatments with different irrigation water level (n=3, p<0.05), and AOB amounts were significantly higher in the treatments of HHOM and LNPK than in other treatments. The nitrification potential was significantly higher in the low irrigation water level treatment(LNPK) than in other treatments, but nitrification potential was not significantly different in other soils. The result of Ammonia-oxidizing archaea (AOA) enrichment experiment showed that AOA could be enriched under laboratory condition.

Keywords: rice soils; Ammonia-oxidizing bacteria; Ammonia-oxidizing archaea; Nitrification potential

　　　研究不同施肥类型、施肥量和灌溉水位对土壤硝化微生物和硝化作用的影响及机理意义重大。采用PCR-DGGE、实时定量PCR和核酸序列分析等手段研究不同施肥类型、施肥量和灌溉水位处理中土壤硝化微生物的群落结构和数量，结合土壤硝化能力的强弱，揭示土壤中氮的转化规律。在此基础上合理施用肥料，对提高肥料利用率和实现作物增产和土壤保肥具有重要意义。