Study On Microbe Consortium Of N Transformation And Its Mechanism For N Conservation Of A Swine Manure-straw Compost

Microorganism is the executor of substance transformation, also N removalmicroorganism undertake the N conversion. Nitrogen removal process mainly includesammoniation, nitrification, denitrification, azotification during composting. Those steps areconducted by ammonifier, nitrifier, denitrifier, azotobacter. Therefore the foundation ofnitrogen transformation controling is characteristics of motion and mechanism of action onnitrogen during composting. It is important to understand the functions, characteristics andinterrelationship of four kinds of bacteria with the aim of clarifying the microbial mechanismsof nitrogen removal. Microbe consortium of high nitrogen retention is studied from the viewof microbial physiological group during N cycle. So it is better to restore nitrogen andaccelerate compost efficiently. Pig manur and wheat straw were taken as materials,in order todiscuss the function of microbial physiological group in carbon and nitrogen transformationduring the swine manure-straw composting.7strains N transformation bacteria includedammonifier, nitrifier, denitrifier, azotobacte were isolated and screened from poultryexcrement compost（pig manur, cow dung, cattle dung, chicken manur）and the hightemperature swine manure-straw samples; Microbe consortium, contained excellentmicroorganism of different or identical strain, were inoculated small simulation compostingprocess. We determined the best compound bacterium agents for increasing heating andsaving nitrogen. Finally，the effects of the best microbe consortium on swine manure-strawcomposting were discussed at different inoculation amounts composting time. The mainresults were as follows:（1）40.2%of original amount N was lost during composting,49%of N was lost duringthe high temperature period. The ammonifiers amount increased significantly duringthemophilic period（39℃-63℃） and have a significant positive correlation with theconcentrations of NH4+-N and NH3. The amount of nitrifying bacteria and denitrifiers wereall positively related with the NO3--N contents during the composting. The denitrifiersincreased significantly at the cooling composting stage and its amount were13times higherafter cooling stage than at the initial stage. The NO3--N concentration increased by87.5% after composting. The increase of NO3--N concentration increased might be partly explainedby its relation with nrtirfication of denitrifiers. The azotobacter amounts increased2.61timesduring the composting, which has a significant positive correlation with the concentrations ofNH₄⁺-N and organicN.（2）There were7strains of nitrogen removal bacteria with high activity were isolatedduring composting:2strains of ammonifiers came from cow dung matured compost and hightemperature swine manure-straw samples,2strains of heterotrophic nitrosation bacteriascame from chicken manur matured compost,2strains of denitrifier came from pig manur andcow dung matured compost,1strain of azotobacte came from pig manur matured compost.（3） The predominant strain inoculated in small-sized simulation composting experiment.The nitrogen removal microbe consortium had the best characteristic of the basicphysicochemical properties、N forms change and carbon degradation terms during the swinemanure-straw composting. The best composting went into themophilic period of9days on thesecond day. Compared with initial stage, ammonium nitrogen、total nitrogen increased by68%and34.9%respectively, the NO-3-N increased from0.1g/kg to1.62g/kg, and thedecrease rate of organic carbon was34.7%in the end.（4） The best microbe consortium, inoculated swine manure-straw composting, werediscussed at different inoculation amounts and time. The results indicated that inoculating1%at beginning went into themophilic period（≥50℃） of17days on the third day. Compared withinitial stage, ammonium nitrogen of five treatments（CK,1,1%, LB,CK,1,3%,12,1%）decreased by87.5%,58.4%,59.7%,75.2%,85.2%respectively. The NO3—N in fivetreatments（CK,1,1%, LB,CK,1,3%,12,1%）increased49.7%,61.1%,-19.6%,31.9%,68.4%respectively. Organic nitrogen of five treatments（CK,1,1%, LB,CK,1,,3%,12,1%）increased25.3%,39.8%,26.2%,27.8%,21.9%respectively. Organic carbon of five treatments（CK,1,1%, LB,CK,1,3%,12,1%） decreased by18.6%,31.4%,31.1%,27.5%,22.4%respectivelyin the end. GI of five treatments（CK,1,1%, LB,CK,1,3%,12,1%）were83%,85%,82%,60%,63%respectively. Seed germinate rate of inclinating1%,1%LB,0（thecontrol） on the first day which were non-toxic for plants as manure were between80%and85%. Inoculating inoculating on the first day was more effective than others. The increase rateof organic nitrogen was highest. Total nitrogen loss was smallest, which was good for Nsaving. The reduction of organic carbon was lower than others. Iinclinating1%werenon-toxic for plants as manure on the first day.