Effects of biochar amendment on the abundance and community structure of nitrogen-fixing microbes in a coastal alkaline soil
Biochar amendment may affect abundance and diversity of soil microbial community.However,the effects of biochar amendment on nitrogen-fixing bacterial community in coastal alkaline soils remain unclear.Using real-time quantitative PCR and DGGE profiling,this study investigated the variations of abundance and diversity of nifH genes in a coastal alkaline soil amended with different doses (0,5％,10％,20％,w/w) of biochar during an 84-day incubation.This microcosm experiment showed that the incubation time significantly influenced nifH gene abundance (P＜0.05),but no differences were observed among treatments (P＞0.05).Following 14-day incubation,the copy number of niifHgenes was significantly stimulated.On the 42nd day,the nifH abundance in the 20％ biochar treatment was significantly higher than that in the control.For the 10％ biochar treatment,however,higher abundance of nifH was observed on the 56th day,compared with the control.NMDS and CLUSTER analyses showed that the samples could be separated into two major groups,the low-dose group (0 and 5％ biochar treatments)and the high-dose group (10％ and 20％ biochar treatments).ANOSIM indicated that the dose of biochar application significantly affected the community structure of nitrogen-fixing microbes in the coastal soil (P=0.001).DGGE analysis and sequencing of the major bands indicated that the relative abundance of Ideonella and Skermanella increased following biochar amendment,whereas the population of Azospirillum,an important nitrogen-fixer,remained relatively stable.
国家科技期刊平台
NSTL
万方数据
维普
