| Nitrification plays a very important role in the nitrogen cycle, its role is to refer to the conversion of ammonia in the process of nitrification in the soil under the action generated by the ammoniated become HNO3, then the formation of nitrate and soil Metal Ions process, thereby providing nutrients for plant growth. The ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) are a class capable of oxidizing ammonia to nitrite bacteria, is widely distributed in most of the soil, freshwater and marine environments, the soil nitrogen cycle plays an important and role, so research in the field of microbial ecology, has become a model organism for the study. About the nitrification, at home and abroad has accumulated a wealth of experience, combined with long-term soil fertility vegetable features plain areas to improve soil fertility, reduce soil N losses as the goal has always been widespread concern hotspot, in addition, as the number and population structure of ammonia-oxidizing bacteria and ammonia-oxidizing archaea for soil nitrogen transformation plays a very important role, so this paper soil sample Hunan Agricultural University Park Yun vegetable planting base for the object to study, discuss organic manure and inorganic fertilizer fertilizers on long-term vegetable acidic soil nitrification bacterial diversity. To reveal the organic fertilizer and inorganic chemical fertilizer affect long-term vegetable cultivation on soil nitrification and nitrifying bacteria change impacts, provide a theoretical basis for the scientific fertilization, promote full utilization of nitrogen.In this study, samples were collected from Hunan Agricultural University, Park Yun vegetable planting base. Pilot program for a randomized complete block design, set up a total of four different treatments with three replicates setting, handling one:just a simple application of phosphate fertilizer and potash fertilizer, organic fertilizer and no fertilizer; Processing Ⅱ:application of nitrogen, phosphorus and three kinds of potash fertilizer, but not organic fertilizer; processing III:application of fresh manure organic fertilizer, while the distribution of nitrogen, phosphorus and potassium fertilizers; handle four: pig manure composting of organic fertilizer, while the distribution of nitrogen, phosphorus, three kinds of potassium fertilizers. After the determination of the chemical nature of the soil, the release and soil nitrification and microbial biomass carbon and nitrogen content of N2O.Using the kit method adopted by direct extraction of total DNA of microorganisms in soil samples, and then the ammonia-oxidizing bacteria and ammonia-oxidizing archaea functional genes-ammonia monooxygenase gene primers were designed to amplify the target gene fragments, built AOB and AOA’s amoA clone library, and analyze the diversity of its community structure.The results show that:(1) After using fresh manure and inorganic fertilizer together with the application and swine manure with inorganic fertilizer application process with the distribution compared with only inorganic fertilizer for soil treatment, and its potential to lower soil nitrification, ammonia oxidation potential also relatively lower content of nitrate and ammonium nitrogen content but lower than inorganic fertilizers and organic fertilizers treatment are higher..(2) Microbial biomass carbon content of each fertilization treatment is 194.71-798.38 mg/kg, microbial biomass nitrogen content of 49.23-97.13 mg/kg. Inorganic fertilizers and organic manure with application processing and simple compared with soil inorganic fertilizer treatment, the microbial biomass C and microbial N content has increased.(3) Each treatment ammonia-oxidizing bacteria were obtained from soil samples of four different fertilization treatments in 150 libraries of sequences obtained 129 ammonia-oxidizing archaea four kinds of treatment, respectively,134,138,147 sequence library sequences, and OTU sequences for library classification and diversity analysis and build scarcity curve. Ammonia-oxidizing bacteria, including libraries, respectively 10,14,13 and 8 OTU, ammonia-oxidizing archaea library include 10,14,13 and 8 respectively OTU.(4) Diversity index showed differences in population diversity of inorganic fertilizer and organic manure fertilizer different manner of AOB and AOA in soil organic fertilizer, ammonia oxidizing bacteria OTU B2 contains the largest number, at the same time and B2 shannon highest index, showed the highest diversity of species abundance B2 library; OTU number of ammonia-oxidizing archaea G2 contains relatively the most, and the highest relative shannon index, the higher the library diversity index, the number of ammonia-oxidizing archaea OTU also included more.(5) amoA gene library constructed based display, four kinds of processing advantages AOB populations belong Nitrosospira sp., Nitrosolobus mtiformis, dominant populations of four kinds of treament of anmmonia-xidizing archaea are Desulurococcales and Methanococcales. |
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