Effects Of Slag And Biochar On The Soil Physical And Chemical Properties And DIRB Of Paddy

Dissimilated iron reduction is a process of reducing Fe（Ⅲ）as an electron acceptor and organic matter as an electron donor,and reducing Fe（Ⅲ）to Fe（Ⅱ）.This process occurs naturally in the anaerobic environment such as soil,water and sediment.It is one of the most important geochemical processes.The known iron reducing bacteria such as Bacillus family members,Shewanella genus can be used to restore,precursors of competition methane production,resulting in methane emissions reduction.Studies have shown that when biochar and slag are applied to soil,they will have certain effects on soil bulk density,porosity and nutrient content,which will directly or indirectly affect soil microecological environment.The purpose of this study is to discuss the relationship between applied slag and biochar and paddy soil micro environment and microbial iron reduction,iron metabolism in bacteria,slag and biochar applied single and mixed applied treatment on paddy fields,and to exert treatment as control.The differences of soil physical and chemical properties,nutrients,Fe（Ⅲ）reduction,the thickness of iron film on root surface,the total number of bacteria and the composition of iron reducing bacteria community in different growth stages were analyzed.The following main research results are obtained:1.Applied to change the soil bulk density of slag and biochar,the specific performance of biochar could reduce soil bulk density,and the application of slag is not obvious change on soil,slag and biochar applied mixed can reduce soil bulk density;applying slag and biochar can improve the soil conductivity,better effect biological carbon,biological carbon slag and the most obvious effect of applying mixed fertilizer could improve soil;pH biochar,applied to the soil pH changed little slag;exert little impact on total nitrogen and available phosphorus of soil total organic carbon,slag and biochar.2.Whether the early and late stage of iron reduction bacteria than milk stage,biochar applied group iron reducingbacteria compared to the other three groups will be high;early and late rice total iron content is relatively stable,exert little impact on the total slag and biochar;biochar can improve soil applied in the Fe（Ⅱ）content,especially in the period of rice growth.The application of slag and biological carbon can reduce the content of iron film in rice root surface.3.Applying little effect on soil bacterial abundance of slag and the biological carbon growth process in late,and for early rice,biochar applied and slag and biochar applied will reduce the bacterial abundance mixed;early and late rice in soil samples of bacteria are mainly distributed in the six Phylum,respectively,Proteobacteria（Proteobacteria）,acidobacteria（Acidobacteria）,Firmicutes（Firmicutes）,actinobacteria（Actinobacteria）,nitrate（Nitrospirae）,magneticum door bacteriodetes（Bacteroidetes）.The genus of the top ten relative abundances included Bacillus,Erysipelothrix,Koculia,Anaeromyxobacter,Clostridium_sensu_stricto₁,Haliangium,Anaerolinea,Clostridium_sensu stricto₁2,Halomonas,Truepera.Early rice control（Ec）and early rice slag application group（Es）,late rice control group（Lc）and late rice mixed group（Lm）,late rice slag application group（Ls）and late rice biochar application group（Lb）,these groups the community composition of the samples is relatively close.4.Early and late rice in soil samples detected by iron reducing bacteria distributed in alpha Proteobacteria（alpha-Proteobacteria）,beta Proteobacteria（beta-Proteobacteria）,gamma Proteobacteria（gamma-Proteobacteria）,delta Proteobacteria（8-Proteobacteria）,bacilli（Bacillus）,clostridia（clostridia）.The dominant iron reducing bacteria are Bacillus,Anaeromyxobacter,Clostridium,Thiobacillus,Geobacter,Desulfobulbus,Deferrisoma,Acidothermus,and Geothermobacter.The application of slag and biochar,to a certain extent,will change the composition of the soil microbial flora.