Effect Of Covering Compost And Inculation On Nitrogen Transform And Compost Quality In Pig Manure-straw Composting

To conserve nitrogen and nutrition, reduce environment pollution and improve quality ofproduct during composting, in this paper, with the covering-compost and inculcation astreatments, first focus was the effect of covering matured compost on nitrogen transform,variation of microbial community and quality in pig manure-wheat straw composting. Secondwas the effects inculcating ammonifying bacteria at beginning, nitrite bacteria after the hightemperature period and covering fast compost on transform and quality in composting. Thelast was the combined effect of covering fast compost and inculcation on the compost’stemperature. The main results obtained are listed as follows:（1）In the experiment of covering matured compost, the results indicated that:CT（Covering Treatment） can reduce water content, pH, and GI and increase EC inCT-UL（Under layer）. Compared to CK （Control Check）, CT can’t reduce but can delayammonia emission; CT decreased the drop of NH₄⁺-N by8%, increased NO₃^--N andOrganic-N by66.7and26.9%. In CT-UL, TN, available N, TP incresed by27.4,52.0and72.2%, but the drop of TOC and humus content decreased by1.1%and3.7%compared to CK;（4）CT-TL（Top layer） got NH3from CT-UL in early period of composting to nitrify, so theNO₃^--N increased dramatically after high temperature period. CT-TL had mineralized andinfluenced on nitrogen transformation and compost quality in CT-UL.（2）The final microbial community structures of CT-UL and CK were similar, the maindifference was the capacity to utilize C of the microbial community of CT-UL in temperaturerising period and high temperature period was lower, and CT-UL conserve more easilydegradable C which was utilized in curing period. And these carbon promoted there-colonization of Fungi and actinomycetes, promoted the degradation of resistant degradableC and increased the content of microbial biomass. From the point that the good maturity wasfinal compost should conserve certain extent of microbial activity to suppress plant pathogens,the46d compost of CT-UL both had better nutrition and extent of microbial activity. In orderto prevent nutrition loss of CT-UL, air drying was suggested.（3）In the experiment of inoculation, inoculating ammonifying bacteria at the beginningtreatment（A） extended high temperature period for2d and increased the average temperature for0.7℃, increased the mean value of NH₄⁺-N, NO₃^--N, increasing range of total K anddecreasing range of organic-C, decreased the increasing range of organic-N and total P, andhad few effects on moisture, pH and EC. By27d, EC of A was21.4%higher than CK, andavailable N, moisture, GI, NO₃^--N, total N, total P, and total K were lower than CK by2.9%、8.5%,36.3%,18.2%,1.2%,35.7%and11.1%.Inoculating nitrite bacteria after high temperature treatment（N） decreased mean value ofNO₃^--N, decreasing range of organic-C and increasing range of organic-N, had few effects onmoisture, pH, EC and mean value of NH₄⁺-N. By27d, moisture, pH, GI and NH₄⁺-N werehigher than CK by5.3%,3.6%,11.3%and54.2%. NO₃^--N, total N, total P and total K werelower by36.4%,10.9%,4.4%and15.4%.（4） In the experiment of covering fast compost, being covered fast compost as underlayer in fast degrading period treatment（U-A-2） increased the decreasing range of NH₄⁺-Nand increasing range of organic N, decreased the decreasing range of moisture, organic C andthe increasing range of pH, NO₃^--N in whole process.In the post-compost period, circulating covering as top layer treatment（T-CK） increasedthe increasing range of pH, NO₃^--N and decreasing range of GI, decreased the decreasingrange of moisture, organic C and increasing range of EC, NH₄⁺-N. EC, GI and total N ofcompost product were lower than its control check（CK-2） higher by41.2%,66.5%and5.3%,available N, total P and total K were higher416.7%,12.1%and6.1%。In the post-compost period, being covered as under layer in fast degrading period thencirculating cover as top layer in post period treatment（T-U-A）, compared with its controlcheck（U-A-2）, increased the increasing range of pH, EC, organic N and decreasing range ofGI, organic C. Expect GI was lower by41.0%, pH, EC, available N, total N, total P and totalK were higher12.9%,4.7%,237.5%,356.0%,13.2%and14.2%，respectively.（5） Being covered by fast compost had the disadvantage of compost temperature, andinoculation of ammonifying bacteria can overcome the disadvantage. Inculcation of nitritebacteria in top layer restrain temperature.