Effect of Different Proportions of Three Microbial Agents on Ammonia Mitigation during the Composting of Layer Manure

Abstract

Odor emissions represent one of the important issues of aerobic composting. The addition of microbial agents to compost is an important method for solving this problem, but this process is often unstable when a single microbial agent is added to the compost. Therefore, in this study, five treatments comprising different proportions of Bacillus stearothermophilus, Candida utilis, and Bacillus subtilis were tested to determine the best combination of the three microbial agents for ammonia reduction, as follows: control group (CK), 2:1:1 (A), 1:1:2 (B), 1:2:1 (C), and 1:1:1 (D). Compared with the CK group, the A, B, C, and D groups reduced ammonia emissions by 17.02, 9.68, 53.11, and 46.23%, respectively. The total ammonia emissions were significantly lower in C and D than in CK (p < 0.05). These two treatment groups had significantly increased nitrate nitrogen concentrations and decreased pH values and ammonium nitrogen concentrations (p < 0.05). Throughout the composting process, the total bacterial number was significantly higher in C and D than in CK (p < 0.05). Therefore, it is likely that B. stearothermophilus, C. utilis, and B. subtilis compounded from 1:2:1 (C) to 1:1:1 (D) reduced the ammonia emissions due to (1) a reduction in the pH and (2) the promotion of the growth of ammonia-oxidizing bacteria and the conversion of ammonium nitrogen to nitrate nitrogen. This study provides a theoretical basis and technical support for the odor problem of layer manure compost and promotes the development of composting technology.

Investigation of a night soil compost psychrotrophic bacteriumGlutamicibacter arilaitensisLJH19 for its safety, efficient hydrolytic and plant growth-promoting potential

“…These values are quite low in the case of PGP attributes. But, in the case of composting, ammonia gas released by bacteria is primarily responsible for pungent smell and loss of organic nitrogen from the compost (Zhou et al, 2019). This may suggest that it doesn’t directly benefit the plants but may be able to maintain stable organic nitrogen content in the compost by not converting rich nitrogenous sources into ammonia gas.…”

Comparative Genomics and Physiological Investigation Supported Safety, Cold Adaptation, Efficient Hydrolytic and Plant Growth-promoting Potential of Psychrotrophic Glutamicibacter Arilaitensis LJH19, Isolated from Night-Soil Compost

“…However, these values are relatively low in the case of PGP attributes. In the composting case, ammonia gas released by bacteria is primarily responsible for the pungent smell and loss of organic nitrogen from the compost [24]. This may suggest that it doesn't directly bene t the plants but may maintain stable organic nitrogen content in the compost by not converting rich nitrogenous sources into ammonia gas.…”

Effect of Cornstalk Biochar Immobilized Bacteria on Ammonia Reduction in Laying Hen Manure Composting

“…The mixed bacteria consisted of Bacillus stearothermophilus, Candida utilis, and Bacillus subtilis in a 1:2:1 ratio, which were purchased from the Center of Microbial Culture Preservation in Guangdong. The strains and their ratios were chosen on the basis of their maximum effectiveness in the removal of NH 3 , and antagonistic interactions between them [3]. Laying hen manure was collected from a chicken farm located at the Institute of Animal Science, South China Agricultural University, while sawdust residue was from the Zengcheng District, Guangzhou, China.…”

“…Wang et al (2019) added 8g/kg of Bacillus stearothermophilus to manure composting and found that the NH 3 emission was reduced by 11.21% [23]. Our previous study found that adding a small amount (5%) of complex bacteria (Bacillus stearothermophilus, Candida utilis, and Bacillus subtilis) to a small simulated experimental study of laying hen manure compost could have a certain inhibitory effect on NH 3 , and the highest removal rate could reach 53.11% [3].…”

“…Egg production has been increasing worldwide [1][2][3], and to meet the needs of consumers, a large number of laying hens are farmed. This has produced a huge quantity of feces that require treatment [4,5].…”