| Industrial and agricultural production boost the economic development as well as produce large quantities of solid organic waste, which will not only be a waste of resources, but also exacerbate environmental pollution without timely and effectively treated. Intensive agricultural cultivation mode, such as monoculture, will lead to the outbreak of soil-borne disease, which has caused a serious threaten to crop production.Bacterial wilt of tomato is caused by Ralsonia solanacearum, and has become a major limiting factor in tomato industry. Application of bio-organic fertilizer and bio-nursery substrate (common nursery substrate mixed with antagonistic microbes) are two important biocontrol ways in suppression of soil-borne disease. In the first part of this study, effects of different proportions of rice husk and different inoculants including composting microbes and matured compost on the high-temperature composting efficiency were investigated. Spectroscopic techniques and high-throughput sequencing technology were applied to investigate structure variations of composting materials and dynamic changes of microbial communities during composting process, respectively. In the second part of this study, waste proteins including blue algal sludge, rapeseed meal,and feather powder were utilized to create high-quality organic fertilizer and bio-organic fertilizer, the greenhouse and field experiments were carried out to evaluate their effects on plant growth. Variations of material structures during fermentation process were also explored. At last, bio-organic fertilizer and bio-nursery substrate were jointly applied in tomato monoculture system to evaluate their effects on suppression of soil-borne tomato bacterial wilt and soil microbial communities. The main results were obtained as follows:1 . As revealed by physical and chemical indicators and three-dimensional fluorescence spectra, faster degradation rates of cellulose and hemicellulose and higher composting efficiency were observed in pile B (added 50% of rice husk) as compared to pile A (added 15% of rice husk). Different microbial communities affected composting efficiency by altered C/N ratio of composting piles. Results of 454 pyrosequencing indicated that the relative abundance of bacterial genus of Tissierella, Natronincola,Anaerosalibacter, Enterococcus, Exiguobacterium, Eggerthia and fungal genus of Piciha from pile B in heating phase were higher than that in pile A. The results of spearman correlation indicated bacterial genus of Dietzia, Nocardiopsis, Thermobifida,Elizabethkingia, Haliscomenobacter, Saccharococcus and fungal genus of Aspergillus may involved in humic acid formation. Bacterial communities were influenced by the variations of temperature, moisture content, water-soluble carbon content and nitrate content along with the process while fungal communities were affected by the variations of moisture content, water-soluble carbon content and total phosphorus content by variance partition analysis.2 . Addition of composting microbes and matured compost increased the initial composting temperature, and addition of composting microbes showed higher efficiency compared to addition of matured compost. Humic acid-like materials were first formed in the pile inoculated with composting microbes, followed by the pile inoculated with matured compost and the control as revealed by three-dimensional fluorescence spectra,indicating composting process can be accelerated by the two kinds of inoculations.During the heating phase, highest amount of total bacteria and total fungi were observed in the pile added with matured compost, followed by adding composting microbes.Results from 454 pyrosequencing revealed that composting efficiency was promoted by high diversity of microbial communities in initial stage, which shorten composting time and altered the diversity of microbial communities in mature phase. Bacterial community structure was more influenced by composting time than by different treatments. The relative abundance of bacterial genus of Alkaliphilus, Halalkalibacillus,Cerasibacillus,Tepidimicrobium from heating phase and genus of Bacillus, Fontibacillus,Psychrobacillus from thermophilic phase in piles that added composting microbes or matured compost were higher than control. These bacteria promoted composting process and improved composting efficiency as these bacteria can form spores.3 . The addition of blue algal sludge in fermentation process can solve the environmental problem and also improves the quality of organic fertilizer. Added 7% of blue algal sludge increased the amount of nutrients, common free amino acids and total amino acids compared with control. Rapid degradation rates of microcystin-LR and microcystin-RR, higher germination index were observed in the fermentation process.greenhouse experiments showed that application of this novel organic fertilizer efficiently promoted plant growth. Compared with the control, height of cucumbers, peppers,bananas and corns were increased by 77.1%, 54.3%, 40.8% and 25.4%, respectively;stem diameter were improved by 13.1%, 46.8%, 43.5% and 48.2%, respectively; ground fresh biomass were increased by 53.5%, 97.2%, 177% and 142%, respectively;underground fresh biomass were improved by 12.0%, 52.4%, 165% and 38.9% ,respectively.4 . Protein wastes were added in matured compost to improve the quality of bio-organic fertilizer by increasing the biomass of functional microbes (Bacillus amyloliquefaciens SQR9). An optimized raw material composition of solid-state fermentation was obtained by response surface methodology and experimental validation.The results showed that the mixing ratio of rapeseed meal, expanded feather meal, bule algal sludge and chicken manure compost as 7.61: 8.85: 6.47: 77.07 resulted in maximum biomass of strain SQR9 and maximum amount of lipopeptides after 7 days solid-state fermentation. Plant growth was promoted by the novel bio-organic fertilizer, application of which increased 33.7% of plant height and 5.2% of stem diameter for eggplant in the first season, and increased 33.2% of plant height and 11.6% of stem diameter in the second season compared with control applied with chemical fertilizer in greenhouse experiments. In the field experiment, application of bio-organic fertilizer not only increased agronomic properties of eggplant but also increased the Vitamin C content and soluble sugar content of the fruit. Compared with control applied with chemical fertilizer and treatment applied with organic fertilizer, application of bio-organic fertilizer increased the fruit yield by 11.9% and 11.2% in the first season, and by 57.2% and 29.2%in the second season.5 . In tomato monoculture system, application of bio-organic fertilizer (nBIO)significantly increased tomato yield and reduced disease incidence as well. Higher tomato yield and lower disease incidence were observed in the treatment combined application used of bio-organic fertilizer (nBIO) and bio-nursery substrate (BIONS) compared to only application of nBIO or other treatments.Compared to chemical fertilizer (CF) and organic fertilizer treatments (nOF), continuous application of nBIO increased 62.0% and 35.0% of tomato yield, for the second season, and 198% and 67.4%, for the third season respectively. However the values of application of BIONS were 81.6% and 50.7%, for the second season, and 314% and 132%, for the third season respectively. After continuous application for five-seasons, the gap of fruit yield among different fertilization model were wider, and application of BIONS increased 330.6% of the tomato yield. After continuous application for three seasons, compared to application of chemical fertilizer and organic fertilizer, the disease incidences in nBIO and BIONS treatment were decreased by 48.8%, 33.3% and 76.8%, 69.1%, respectively. While after application for five seasons, nBIO treatment decreased the disease incidence by 30.2% and 16.7%.BIONS application inhibited 44.8% and 31.3% of disease incidence. Moreover,application of nBIO or BIONS improved fruit quality. Application of BIONS improved 69.6% of titratable acidity content and 40.5% of soluble sugar amount of tomato fruit compared to the application of chemical fertilizer.6. Monoculture increasd abundance of fungal and pathogens. However the relative abundance of pathogens were both decreased by the application of nBIO and BIONS,additionally increased biomass of bacteria were observed in these treatments as compared to CF and nOF treatments. The next-generation sequencing of the 16S rRNA and internal transcribed spacer (ITS) genes using MiSeq platform showed that lower fungal diversity and higher bacterial richness and diversity were observed in rhizosphere soils amended with continuous application of BIONS for three seasons as compared to soils applied by CF. Moreover, the relative abundance of bacterial genus of Chryseobacterium,Lysobacter, Luteimonas, Sphingobacterium and Shinella from nBIO treated rhizosphere soil were higher than nOF treated rhizosphere soil, and higher relative abundance of Lysobacter, Limnohacter, Burkholderia, Sphingorhabdus, Marinithermus and Succinispira were observed in nBIO treated bulk soil. Further more higher relative abundance of Limnobacter, Thalassolituus, Sphingomonas, Burkholderia, Lysobacter,Luteimonas, Rhodanobacter, Acetitomaculum and Rhodovibrio were observed in BIONS treated bulk soil. Venn diagram revealed that the microbial communities from bulk soil were built by application of different fertilizers and the microbial communities from bulk soil affected the microbial communities from rhizosphere soil. Relative abundance of Ralstonia in rhizosphere soil was much higher than that in bulk soil, both of which showed positive linear correlation with disease incidence. The relative abundance of Ralstonia in bulk soil showed significantly negative correlation with nitrate content and positive correlation with C/N ratio while significantly positive correlation with pH and negative correlation with EC and total phosphorus content in rhizosphere soil were observed.7. Continuous application of nBIO for five reasons significantly increased EC value and nitrogen content and decreased available phosphorus and nitrate contents compared with nOF treatment. The next-generation sequencing of the 16S rRNA and internal transcribed spacer (ITS) genes using MiSeq platform showed that the soil bacterial and fungal community structures were altered by application of nBIO and BIONS and greater variation was observed in rhizosphere soil than in bulk soil. The relative abundance of Ralsionia in bulk and rhizosphere soils decreased after continuous application of nBIO and BIONS for five seasons compared with with nOF. The relative abundance of Ralstonia in bulk soil from nBIO and BIONS treatments decreased 67.0% and 67.8%than that from nOF treatment respectively. However the value in rhizosphere soil from nBIO and BIONS treatments decresed 18.7% and 71.0% of the relative abundance of Ralsionia from nOF treated rhizosphere soil. Continuous application of BIONS for five seasons increased the relative abundance of Bacillus and Pseudomonas in rhizosphere soil while Bacillus only in bulk soil. Microbial networks were built based on random matrix showed continuous application of nBIO for five seasons improved the stability of fungal network from bulk soil and bacterial network from bulk soil, while continuous application of BIONS for five seasons enhanced the stability of bacterial network from rhizosphere soil.In conclusion, appropriate C/N ratio and added composting microbes or matured compost can improve the efficiency of composting. Mixed blue algal sludge, rapeseed meal, expanded feather meal and matured chicken manure by solid-state fermentation achieved resources utilization, improving the quality of fertilizer. This novel organic fertilizer or bio-organic fertilizer promoted plant growth and increased yield. These fertilizers had amino acid, lipopeptides and functional and functional microbes that were the reasons for these fertilizers had such effects. Continuous combined using of bio-substrate and bio-organic fertilizer can improve tomato yield and fruit quality,reduced the incidence of soil-borne tomato bacterial wilt. The reason as follow: 1) it reduced the relative abundance and amount of Ralsionia from bulk soil and rhizosphere soil. 2) It increased the relative abundance of Pseudomonas from rhizosphere soil and Bacillus from both bulk soil and rhizosphere soil. 3) It improved the degree of ordering of microbial communities and enhanced the stability of the microbial networks. Therefore,this study obtained a high efficient, high-quality and sustainable development of farming mode. |
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