Straw Mulching and Nitrogen Fertilization Affect Diazotroph Communities in Wheat Rhizosphere

Diazotrophs that carry out the biological fixation of atmospheric dinitrogen (N 2 ) replenish biologically available nitrogen (N) in soil and are influenced by input inorganic organic substrates. To date, little is known about effects combined substrate addition N fertilization on diazotroph community composition structure purple soils. We investigated straw mulching communities quantifying sequencing nifH gene wheat rhizosphere. The abundance richness diazotrophs were greater higher level mulched treatments, whereas nonmulched treatments (NSMs), was lowest with highest level. α-diversity correlated most properties but not pH. At genus level, relative abundances Azospirillum , Bacillus Geobacter NSMs those Pseudacidovorax Skermanella Azospira Paraburkholderia Azotobacter Desulfovibrio Klebsiella Pelomonas treatments. differences between associated temperature carbon potassium contents C:N ratio. Overall, changes alkaline