Bacterial and Fungal Community Dynamics and Shaping Factors During Agricultural Waste Composting with Zeolite and Biochar Addition

Xin Wu,Lihua Zhang,Liheng Ren,Hongli Huang,Jiachao Zhang,Lin Luo

doi:10.3390/su12177082

Abstract

Bacterial and fungal communities play significant roles in waste biodegradation and nutrient reservation during composting. Biochar and zeolite were widely reported to directly or indirectly promote microbial growth. Therefore, the effects of zeolite and biochar on the abundance and structure of bacterial and fungal communities and their shaping factors during the composting of agricultural waste were studied. Four treatments were carried out as follows: Run A as the control without any addition, Run B with zeolite (5%), Run C with biochar (5%), and Run D with zeolite (5%) and biochar (5%), respectively. The bacterial and fungal community structures were detected by high-throughput sequencing. Redundancy analysis was used for determining the relationship between community structure and physico-chemical parameters. The results indicated that the addition of biochar and zeolite changed the physico-chemical parameters (e.g., pile temperature, pH, total organic matter, ammonium, nitrate, and water-soluble carbon) during the composting process. Zeolite and biochar significantly changed the structure and diversity of bacterial and fungal populations. Moreover, the bacterial community rather than the fungal community was sensitive to the biochar and zeolite addition during the composting process. Community phylogenetic characteristics showed that Nocardiopsaceae, Bacillaceae, Leuconostocaceae, Phyllobacteriaceae, and Xanthomonadaceae were the predominant bacterial species at the family-level. Chaetomiaceae and Trichocomaceae were the two most dominant fungal species. The pH, total organic matter, and nitrate were the most important factors affecting the bacterial and fungal population changes during the composting process.

Highlights

Composting has been widely considered to be an efficient way to convert organic wastes into valuable products [1,2,3]
8.78%, 3.50%, 16.13%, and 17.00%, respectively. These results suggested that biochar affected the growth and reproduction of Trichocomaceae, and the mixture of zeolite and biochar was more conducivSuestationabTilritiyc2h02o0,c1o2,m70a82ceae in the later composting process
During the thermophilic and cooling phases, the NH3 volatilization was reduced significantly due to the addition of biochar, and the pile temperature and NO3−-N were increased throughout the composting process [17]

Summary

Introduction

Composting has been widely considered to be an efficient way to convert organic wastes into valuable products [1,2,3]. According to the International Panel on Climate Change (IPCC), CH4 and N2O contribute 30 and 210 times more to global warming than carbon dioxide (CO2), respectively The release of these gases will reduce compost nutrients and cause serious air pollution [4,6,7]. Additives of alkaline minerals (e.g., coal zeolite, fly ash, bentonite, and red mud) have been proved to be effective in improving compost fertility [9,10,11]. Among these additives, zeolite is widely used in nitrogen conservation research, as its substance has the crystalline hydrate aluminosilicate and excellent high negative charge sites of alkaline metals. The added biochar alleviates the initial low pH at the thermophilic stage during composting [17]

Methods

Results

Discussion

Conclusion