Microbial communities in paddy fields in the Mekong delta of Vietnam

摘要: Rice paddy fields are considered to be unique ecosystems. Intensive rice cultivation was developed increase yield and meet the need of food security. This practice has many negative effects on soil ecosystem, such as reduction nutrients, water pollution in soil-borne plant pathogens a possible microorganism diversity. Alternative management strategies required counteract these maintain fertility. The aims this thesis investigate microbial community field assess influence microorganisms degree crop residue degradation protecting next against pathogens, including Rhizoctonia solani, understand relationship between diversity functional groups involved straw inhibition R. solani growth. Furthermore, effect intensive yield, abundance total bacterial diazotrophic compared with rotation system is investigated. Bacteria isolated from stubble both cellulolytic combined chitinolytic activity were phylogenetically linked distinct groups. Selected isolates functions inhibited growth agar plates; most seemed neutral respect their seed germination radicle length. There positive weight loss number Fungal more important for than bacteria. when it inoculated degraded straw. solani. Finally, practices had significant production structure. all rotations that included maize and/or mungbean significantly higher monoculture. Besides effect, structure potential nitrogen-fixing influenced by detected monoculture soil. This highlights systems impact ecosystem. Results study can applied future development sustainable management.