Studies On Soil Microbial Characteristics Of Brown Soil Under Long-term Fertilization Experiment And Tibet Plateau Soil

In this study, two sites long-term fertilization treatment (control without fertilizers (CK), fertilizers N (N), organic manure (M) and half fertilizers N plus organic manure (M+N)) in Plastic-film Mulching Experiment Station of Shenyang Agriculture University and Tibet Plateau were used for studying soil bacterial diversity and the abundance of some soil microbial groups, i.e. bacteria, fungi, ammonia oxidizing archaea (AOA) and ammonia oxidizing bacteria (AOB). First of all, the basic physichemical properties of soils were tested. Then, a more popular modern molecular method, PCR-DGGE was used to detect the bacterial diversity. At last, the abundance of bacteria, fungi, AOA and AOB were analyzed by Real-Time PCR.The results showed that the soil pH value of fertilizers N treatment was 4.9. It was lower than the other three fertilization treatments in Shenyang long-term fertilization experiment. The contents of N, P and K in the treatments of organic manure and half fertilizers N plus organic manure were higher than control without fertilizers. It is observed that Acidobacteria was the dominant microflora in all fertilization treatments by DGGE analysis. There was great bacterial diversity and Bacillales existed in the treatments received organic manure (M&M+N). The bacterial diversity was the lowest but Actinobacteria was detected in fertilizers N treatment. The result of quantitative analysis showed that bacteria>fungi>AOB >AOA in all fertilization treatments and the copy numbers of all four microbial group were the lowest in fertilizers N treatment.The soil of Tibet Plateau showed alkalescence and the pH values were above 8.5. The contents of soil organic matter and total N at the high altitude area were lower than those at the low altitude area. The result of DGGE analysis showed that Cyanobacteria were the dominant microflora in the soil. Gemmatimonadetes existed in the high altitude soil samples and Actinobacteria were only detected in the low altitude soil samples. In addition, the abundance of AOA was larger than those of AOB at the low altitude area, which was contrary at the high altitude area.