Study On The Activity Of Denitrifying Bacteria And The Vertical Distribution Of N₂O Formation In Paddy Field Soil

The greenhouse gas nitrous oxide?N₂O?is the third largest greenhouse gas after carbon dioxide?CO₂?and methane?CH₄?.Soil?N₂O?emissions account for 60%of the global total.Denitrification in nitrogen cycle is the main microbial process of N₂O release in rice field,and denitrification is the only process that can remove N₂O.In this study,soil samples with a vertical direction of 1m were selected from winter and summer seasons in shaoguan,guangdong and antu,jilin.Through the study of samples in different time and space,acetylene inhibitors and high-throughput sequencing were used.The main research results are as follows:Time scales,the results showed that:shaoguan winter and summer sample point denitrifying bacteria activity,and N₂O formation potential with the depth increase and decrease,and denitrification function gene nirS,nirK,nos Z?abundance also increase with depth.By Spearman(Spearman correlation analysis found that denitrification function gene nirS,nirK,nos Z?abundance and environmental factors?TN,TC and TOM?and denitrification potential?PDA?and nitric oxide generated potential?PNA?there is significant positive correlation.Through high-throughput sequencing and redundancy analysis?RDA?to get the results found that winter and summer sample point nirS model of denitrifying bacteria Bradyrhizobium,nirK type Rhodoplanes and Oricola bacteria genera in the denitrifying bacteria,and nos Z?Mesorhizobium species in terms of type of denitrifying bacteria was a positive correlation with PDA and PNA.The results show that the activity of denitrifying bacteria and the potential of N₂O generation in antu and shaoguan summer sample points decrease with the increase of depth.In addition,the denitrification function gene nirS,nirK,nos Z?abundance with depth increase and decrease.Using Spearman correlation analysis found that figure paddy vertical soil sample points of PDA and PDA by nirS denitrification function gene,nirK and nos Z?abundance and environmental factors?TN,TC,moisture content and PH?.At the same time,RDA analysis results showed that the genera of Steroidobacter,Rhodanobacter,Anaerolinea and Magnetospirillum in nirS type denitrifying bacteria,and Rhodoplanes,Afipia,Pseudooceanicola,Oricola and colobacte in nirK type denitrifying bacteria.Type nos Z?denitrifying bacteria Belnapia,Thiothrix and Halomonas bacteria genera and antu summer paddy vertical soil sample points of PDA and PNA was a positive correlation.Through the above experiment contents can be concluded that denitrification function the abundance of genes and environmental factors?TC,TN,TOM,moisture content and PH?on the activity of denitrifying bacteria and N₂O formation has certain influence,in addition,the space and time differences influence the denitrifying bacteria community structure and thus affects the activity of denitrifying bacteria and N₂O formation of vertical distribution.This research to a certain extent,this study reveals that the activity of denitrifying bacteria and N₂O formation in paddy soil vertical distribution,and the function of denitrifying gene nirS,nirK,nos Z?abundance and community structure and environmental factors.Objective to investigate the formation and removal mechanism of N₂O in denitrification of paddy soil.At the same time,the theoretical basis of N₂O emission reduction in vertical soil of rice field is provided.