Study On Water,Soil And Intestinal Microorganisms In Rice-Crayfish Cultivated Field Under Different Fertilization Modes

Rice-based coculture is one of the sustainable agricultural models because it brings good economic and ecological value to meet people's requirements for pollution-free food.Fertilization play a very important part of rice-based coculture.Rational fertilization mode can improve fertilizer efficiency,improve paddy ecosystem environment,and achieve high quality output of rice and aquatic animals.Although many scholars have studied soil microbes in paddy ecosystems,comprehensive studies in the entire ecosystem have not been reported.To explore the effects of different fertilization treatments on the breeding environment and crayfish.The water,soil physical and chemical properties,water microbes,soil microorganisms,and intestinal microbes of Procambarus clarkii were examined.The aim is to explore the fertilization mode more suitable for rice-based coculture.The main findings are as follows:1.High-throughput sequencing of paddy water bacterial showed that Proteobacteria,Actinobacteria,Bacteroidetes and Cyanobacteria were the main phylum in all treatments.The main genus were Sporichthyaceae hgc I_clade,Limnohabitans,Polynucleobacter,Alpinimonas.In the three models,the bacterial species diversity on organic fertilizer treatment was significantly higher than organic fertilizer plus manure treatment,which the abundance of the bacterial was significantly higher than that of the fertilizer and organic fertilizer plus manure.It is indicated that under the mode of organic fertilizer application,water microorganism had better diversity and its ecosystem was more stable.Although the organic fertilizer treatment reduce the species diversity of bacteria in water,it also can greatly reduce the abundance of cyanobacteria.In this study,the main bacterial species of the water bacterial community in different months was not change during the co-production period.However,the OTU of the three treatments from June to September accounted for 21.10%,24.37%,and 26.93%.The composition of the community structure of water bacteria has changed.In June,the ammonia nitrogen and nitrite nitrogen content were the lowest and p H was the highest and nitrate nitrogen content was higher under chemical fertilizer treatment.Which the Synechococcus was significantly positively correlated with p H and nitrate nitrogen.In July,the ammonia nitrogen and nitrite nitrogen content were the highest under the organic fertilizer treatment,and the Planktothrix was significantly positively correlated with ammonia nitrogen and nitrite nitrogen.2.High-throughput sequencing of soil bacteria showed that the Chloroflexi,Proteobacteria and Acidobacteria were the main phylum in all treatments.The main classes were Anaerolineae,Deltapodeobacteria,Acidobacteria and Nitrospira.In the three treatments,the bacterial abundance and species diversity on organic fertilizer treatment was significantly higher than chemical fertilizer treatment.The biodiversity of soil bacteria can be better improved under the organic fertilizer treatment.The relatively low abundance of the Acidobacteria in the fertilizer treatment may be due to the acidification of the soil.According to the soil bacteria analysis from June to September showed that the relative abundance of the Chloroflexi in the chemical fertilizer treatment was 34.3%,28.33%,27.44%,and 24.02%.The relative abundance of the Chloroflexi in July may be due to the deterioration of water quality affecting its photosynthesis.3.The high-throughput results showed that the common bacteria of crayfish intestinal in the different treatments accounted for 58.1%,indicating that the crayfish had a relatively stable core flora.The Proteobacteria,Tenericutes and Firmicutes were the main phylum in the intestinal microbes of crayfish.The main genus were citrobacter,mollicutes and pseudomonas.The main intestine flora of crayfish are also abundant in the intestine of crab and shrimp.In the chemical fertilizer treatment,the relative abundance of citrobacter was the highest,the crayfish is more likely to have disease because it is a conditional pathogen.In the organic fertilizer add manure treatment,the relative abundance of acinetobacter is significantly higher in the intestinal flora of crayfish,which may be related to the soil environment.