The greatest potential benefit of biochar return on bacterial community structure among three maize-straw products after eight-year field experiment in Mollisols

• Published in: Applied soil ecology : a section of Agriculture, ecosystems & environment Vol. 147; p. 103432
• Main Authors: Qiao, Yunfa, Miao, Shujie, Zhong, Xin, Zhao, Hongfei, Pan, Shiqiu
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-03-2020
• Subjects: Community structure; Illumina sequencing; Soil bacteria; Soil properties; Straw management; Community structure; Soil bacteria; Soil properties; Straw management; Illumina sequencing
• ISSN: 0929-1393; 1873-0272
• DOI: 10.1016/j.apsoil.2019.103432

Although straw return, livestock feeding and biochar return are three major effective approaches of straw utilization, the response of soil bacterial communities to the different straw products, especially after long-term addition, remains unclear. Here, we studied the effects of three types of maize-straw products on bacterial community structure in a Mollisol in northeast China. Original maize straw was fed to cattle and pyrolysed to obtain manure and biochar products, respectively. The original straw and manure were separately added to the top 20 cm of soil annually since 2010, but one-time addition for biochar in 2010, and soil samples were collected in the autumn of 2018. The bacterial α diversity and community structure were investigated based on Illumine MiSeq sequencing. The results showed that original straw return only decreased soil bulk density, while manure and biochar return significantly affected soil properties with increased pH, total C, total N and available K compared with control. In addition, manure return increased the concentrations of total and available P compared to control. Straw products did not impact the Ace and Chao indices but changed the Simpson index. Principal coordinate analysis (PCoA) showed that eight-year straw addition shifted the bacterial community structure and exhibited distinct clustering according to straw products. Moreover, distance-based redundancy analysis (db-RDA) revealed that the microbial community structure among soils was significantly associated with bulk density, pH, total C, available P, total K, NO3−-N and NH4+-N. At the genus level, the abundance of 5 genera decreased and one increased in response to straw return. Manure return induced an increase in the abundance of 2 genera (Mizugakiibacter and Rhizombium) and a decrease in 10 genera. However, the 10 increased and 5 decreased genera with biochar return contributed to the considerable shift of bacterial communities. These results suggested the potential benefits of biochar return in improving bacterial community structure, which might represent a useful strategy for straw utilization.
•Bacterial communities exhibited distinct clustering in three straw-product soils.•Much more bacterial genus increased their abundance in biochar return soils.•Biochar return has the greatest potential benefits to manage crop straw.