| Tobacco-rice rotation was a widespread planting pattern in southern china.In the process of tobacco rice crop rotation,because of increasing planting scale,less planting area and higher labor costs,most of tobacco straw was directly returned through rotary tillage.Before planting tobacco,soil conditioners such as quicklime,dolomite,and so on.were applied in the process of soil ploughing in spring,which could be used to improve soil pH and to kill pathogens.These farming methods existed in tobacco rice rotation district,which could not only provide rich nutrients for soil microbes by rotating straw,and affect microbial growth and reproduction by changing soil pH.This paper was choosed the tobacco rice rotation district in the south of anhui as a typical study area,which was focused around smoke rice straw returned and soil conditioner fertilization affecting on soil microbial diversity and community structure,combined with multivariate analysis of soil physical and chemical properties,trying to clarify the driving factor on the changes of soil microorganism,tobacco district in the south of Anhui and tobacco-rice crop rotation similar tobacco district extension straw returning security to provide theoretical basis and technical support.This paper set up three gyroups field experiment district,namely rod decay test compounds and straw returned test area(group consisted of sandy loam and 2 experimental plot),decomposing and experimental plot sampling time for rod in June 2015,straw returned experimental plot in November 2014 respectively(fall),March 2015(spring),and in June 2015(summer)samples,the soil sample was taken to the soil physical and chemical properties,microbial plate count bacteria,bacteria,PCR-DGGE and high-throughput sequencing analysis.The research results show that the straw returned in the experimental plot,bacteria,overall performance for the spring>autumn>summer loam>sandy soil,performance for straw returned in the loam>straw counters-field set.Fungi number rule in 2 species of soil texture,overall in the number of fungi in autumn>spring>summer in sandy soil,loam in spring>autumn>summer.The quantity of actinomycetes are characterized by spring>autumn>summer.In decomposing and experimental plot rod bacteria number in returning rod cover processing is the highest,lowest in returning rod + quicklime processing;The number of fungi and actinomycetes in 5 deal with no significant difference.Three groups of experimental plot soil pH are acidic.Sand straw counters-field experimental plot and alkali-hydrolysable N content of the organic matter no significant difference between the 6 kinds of processing,rapidly available K content in rice straw counters-field processing both smoke in the highest.Loam straw returned in the experimental plot,apart from the alkaline hydrolysis N rice straw counters-field processing both the physical and chemical properties in the smoke in the highest levels,and in reducing fertilizer processing other physical and chemical properties except alkali-hydrolysable N and pH levels.In tobacco stem rot solution in the test area,the content of total P,available P and available K in five processing difference is not obvious,the content of available K significantly the highest after adding degrading bacteria.Compared with returning rod cover processing,returning rod +quicklime and returning rod + degrading bacteria content of available P increased by 44.77%and 51.88%,respectively,rapidly available K content increased by 36.73%and 55.10%,and the differences were significant(P<0.05).In the sandy soil,different soil bacterial community DGGE spectrum analysis results showed that in terms of the diversity of bacterial community level,TrSrD>TrSr,TrScrQ>TrScr>TnrSnr>TrScrQF.In loamy soil,different treatment bacteria DGGE spectrum analysis results showed that in terms of the diversity of bacterial community level,TrScr>TrSrD>TrSr>TrScrQF>TnrSnr>TrScrQ.Zhang Xi town returning to analyze DGGE results showed that TDB significantly increased soil microbial diversity,TR was higher than TC in microbial diversity,soil microbial diversity of TL had improved significantly compared with TR.Proteobacteria and Acidobacteria were the main advantage bacterium group,and after adding degradation bacteria Nitrospirae increased significantly.The results Using Illumina MiSeq sequencing showed that average length of each sample was 432 bp,each sample was reached more than 30000 high-quality sequences,18 samples were reached a total of 703703 sequences.Samples were identified a total of 31 phylum,69 classes,156 orders,295 families,481 genera,whose numbers were the most in sample of TrScr processing.And microbial diversity index and richness index of TrScr treatment were highest,while they were the lowest in TrScrQF treatment.PCoA and RDA analysis illustrates the different treatment between the three repetition can get together,the distance between TnrSnr treatment and TrSr treatment and between TrSrD treatment andTrScrQ treatment were mush little,explained their community compositions were similar.Proteobacteria accounted for the highest in the level of phylum,Acidobacteria was the second higher phylum,Actinobacteria and Chloroflexi also had a high proportion,their share of different phyla in different treatment.The proportion of different genera in different treatmentwere also different,which were identified and accounted for more than 1%of the total weight had only 20 genera.Seven genera obviously the highest proportion in TrScr treatment.Although microbial diversity of TrScrQF treatment was the lowest,its apparent density and the highest in the soil also have 6 genus of significant difference. |
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