Effects Of Different Additives On The Microbial Community Structure And Deodorization Effect Of Cow Manure Composting

With the increasing demand for livestock and poultry products,the rapid development of large-scale animal husbandry,the production of livestock and poultry manure is also increasing,and the environmental pollution of manure discharge is also increasing,and composting is the most effective way to utilize livestock and poultry manure resources;In this study,the effects of the addition of different rotting fungi agents and auxiliary materials on the physicochemical properties,microbial community and odor emission of cow manure compost were discussed.1.The high temperature period of the treatment group lasted 7-8 days longer than that of the control,indicating that the addition of rotting fungi could prolong the high temperature period of compost,among which the high temperature period of adding solid decay bacteria agent lasted the longest.The moisture content of the treatment group was lower than that of the control,The addition of homemade liquid and solid decay was significantly lower than CK,the germination index of the treatment group was significantly higher than that of CK,the organic matter treated by R1 was significantly lower than that of CK and the total nitrogen of R1 was significantly higher than that of CK,and the commercially available decay agent promoted the degradation of organic matter in the reactor and reduced nitrogen loss;the relative abundance of the dominant flora was different in different places,and the relative abundance of the firmicutes was significantly increased after the addition of homemade fungi at the phylum level,among which R3 treatment was the highest(51.54%),the relative abundance of Bacillus urea,Pyrosporus,Thermophilus,Bacillus,and Limnochorda increased,and the relative abundance of Chryseolinea,Cystosporium and Landcobacterium decreased decreased;The Shannon index and Simpson index after adding liquid fungi were significantly higher than those of other treatments,and AMOVA analysis showed that the differences in bacterial community structure between the treatment group and the control were very significant.CCA analysis showed that the order of physicochemical traits affecting the structure of bacterial community was:GI>MC>OM;The comprehensive evaluation of the effects of different rotting fungi agents on cow manure composting showed that the addition of solid decay fungi agent was the optimal treatment.2.The fermentation time of the treatment group in the warming period decreased by 1～2 d compared with the control,and the fermentation time in the high temperature period(>50℃)increased by 2～6 d compared with CK.After adding fungicide,wheat bran and desulfurized gypsum,the moisture content decreased significantly compared with the control,and the conductivity was less than 4.00 mS · cm-1 at different times.Organic matter decreased by 42.28%～47.98%during the warming period,and after adding desulfurized gypsum,it was significantly higher than that of other treatments;the germination index of the treatment group increased rapidly in the high temperature period and the cooling period,which was significantly higher than that of the control;the pH of each treatment decreased from 8.4 to 7.30～7.63 with the continuation of composting;the total nitrogen showed a trend of first decreasing and then rising,and the carbon-nitrogen ratio decreased from 32.31 to 9.01～10.90;the treatment group and the control group compared bacterial communities in the phylum,There were differences in the relative abundance of dominant flora at the bacterial level;AMOVA analysis showed that the difference in bacterial community structure between the treatment group and the control group was very significant.CCA analysis showed that the physicochemical properties affecting the structure of bacterial community were OM>EC>TN>pH>MC.The indicators were evaluated by the principal component comprehensive score method,and the cow manure+fungus agent 0.1%+rice husk powder 1%+wheat bran 1%in this test was the best composting scheme.3.Compost mixed with cow manure and garden wood chips has a higher temperature,and the highest temperature is optimal in the high temperature period and high temperature period of vermiculite;The moisture content decreased the fastest in 0～7 days of compost,decreased by 13.1%～17.2%,the moisture content of added maifan stone,red clay and vermicure was greater than that of the control group,and the moisture content of microsilica fume and zeolite decreased less than that of the control group.The pH of microsilica powder,added maifan stone,red clay and vermicure was significantly lower than that of the control group(P<0.05),and the conductivity was significantly higher than that of the control group;the experimental group and the treatment group had a higher germination index,and the germination index reached more than 80%in the 21st day,and the organic matter did not change significantly,but the organic matter of each group was greater than 30%at the end of composting,which met the NY/T 525-2021 organic fertilizer standard,and added zeolite,The total nitrogen content of maifan stone was significantly higher than that of the control group,the carbon-to-nitrogen ratio was 30 at the beginning and less than 20 at the end,and total phosphorus and total potassium increased during the composting process,and the addition of zeolite and maifan stone could significantly reduce the emission of ammonia and hydrogen sulfide during the composting process.In summary,the results show that the addition of solid rotting fungi and auxiliary materials to rice husk powder 1%+wheat bran 1%in the composting process of cow manure can help rot,and the addition of 2%zeolite and 2%maifan stone can significantly reduce the emission of ammonia and hydrogen sulfide during the composting process.