| With the rapid development of large-scale and intensive livestock and poultry breeding industry,the environmental pollution problems caused by livestock and poultry manure become more and more serious.Composting is one of the most important techniques to deal with the livestock and poultry manure to be resource,but traditional composting has the shortcomings such as long composting period and low compost quality.Microorganisms play a decisive role in the composting process.The purpose of this study is to develop a composite microbial agent that can promote the composting of pig manure and improve the quality of compost.The main contents and results are as follows:（1）To build composting with pig manure and rice straw.Through monitoring the changes of compost temperature,it was found that the temperature of composting sharply increased to above 50℃in the first 2 days,the peak value of the temperature was 60.05℃,the thermophilic phase maintained 24 d,and the temperature reached to 40℃at 32 d.From the results of temperature change,this composting fermentation rate was fast.So the compost samples collected from the compost could serve as a source for screening the mesophile and thermophile microbes.In this study,using the traditional microbial culture method,three kinds of medium icluding beef extract-peptone medium,PDA medium and Gaoze’s medium were prepared for the isolation.Finally,33 different eugonic strains were isolated from different stages of pig manure composting.（2）Eighteen strains had good subculture,which were selected among the 33 strains obtained from the preliminary screening.They were made to a single liquid agent subsequently,and inoculated into the composting which had sterilized.The effect of the composting was evaluated by the quick indicator when the ratio of water-soluble ammonium nitrogen and nitrate nitrogen is less than or equal to 0.5.And six kinds of strains that can promote composting were screened out by composting effect examination.They were identified by 16Sr DNA,as Gibsonii,Bacillus pumilus,Bacillus amyloliquefaciens,Pantoea agglomerans,Thermobifida fusca,Ureibacillus thermoph-aericus.These six agents were named by ZW16,ZW18,ZW19,ZW22,ZR02 and ZR06respectively.Then 6 strains were mixed into a kind of compound agent.（3）The 6 strains were expanded culture and mixed into a compound bactericide by equal proportion.The homemade agents J1 and two common commercial available agents,Tianyihuiyuan compound microbial agent J2 and VT-1000 compound microbial agent J3were inoculated into the compost respectively,the inoculum size was 0.5%.The effects of different agents were evaluated on physiological and chemical indicators of composting,including temperature,moisture,color,odor,p H,EC,C/N,TOC,TN,TP,TK,GI and so on.The results showed that:Both the treatment and the control group had reached the hygienic requirements for harmless disposal of night soil,that is the composting temperature≥50℃need to maintain at least 10 d or≥60℃need to maintain at least 5 d.Generally,after composting thermophilic phase,when the composting temperature decreased to below 40℃marks the end of the composting fermentation.J1 treatment reached maturity 5 d earlier than the CK,1 d earlier than J2 and J3 treatments.Compared with the initial composting,the final organic carbon content in CK,J1,J2,and J3decreased by 10.58%,14.58%,11.19%,and 11.13%respectively,in which the organic carbon content of J1 treatment decreased significantly more than other treatments.The final total nitrogen content of J1,J2,J3 treatments was 30.83,28.97,and 20.86 g·kg-1,respectively,both of them were higher than the control group(19.35 g·kg-1)at the end of composting.The C/N ratio of CK,J1,J2 and J3 was 21.72,12.90,14.36,19.85,and decreased by 8.51%,50.76%,46.34%and 16.35%,respectively,compared with the initial values.The T value of less than 0.6 was considered as compost to achieve the standard of maturity.J1,J2 treatment reached the compost maturity standard,but J3 treatment and CK didn’t.At the end of composting,the EC value of three kinds of treatments was significantly lower than the CK.The EC value of J1 was the lowest,2.11 m S/cm.The GI values of J1,J2 and J3 were more than 50%at 32 d,42 d and 47 d,reached 50%20 d,10d and 5 d earlier than CK,respectivly;After composting,the GI value of J1,J3 treatment reached 85%of the complete maturity index.In general,the composting which was inoculated homemade agents was shorter,and the toxicity of the compost product was the lower,and the maturity indicators,fertilizer efficiency and the quality was the higher than othetrs. |
PDF Full Text Request