Open AccessDynamics of ammonia‐oxidizing communities in barley‐planted bulk soil and rhizosphere following nitrate and ammonium fertilizer amendment
Author(s) -
Glaser Katrin,
Hackl Evelyn,
Inselsbacher Erich,
Strauss Joseph,
Wanek Wolfgang,
ZechmeisterBoltenstern Sophie,
Sessitsch Angela
Publication year - 2010
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/j.1574-6941.2010.00970.x
Subject(s) - rhizosphere , biology , ammonium , terminal restriction fragment length polymorphism , nitrification , amendment , bulk soil , fertilizer , soil water , agronomy , soil microbiology , relative species abundance , nitrogen cycle , microbial population biology , ammonia , botany , abundance (ecology) , environmental chemistry , ecology , nitrogen , chemistry , bacteria , restriction fragment length polymorphism , polymerase chain reaction , biochemistry , genetics , organic chemistry , gene , law , political science
Oxidation of ammonia by nitrifying microorganisms is a major pathway that fertilizer nitrogen (N) may take upon application to agricultural soils, but the relative roles of bacterial (AOB) vs. archaeal (AOA) ammonia oxidizers are controversial. We explored the effects of various forms of mineral N fertilizer on the AOB and AOA community dynamics in two different soils planted with barley. Ammonia oxidizers were monitored via real‐time PCR and terminal restriction fragment length polymorphism analysis of bacterial and archaeal amoA genes following the addition of either [NH 4 ] 2 SO 4 , NH 4 NO 3 or KNO 3 . AOB and AOA communities were also studied specifically in the rhizospheres of two different barley varieties upon [NH 4 ] 2 SO 4 vs. KNO 3 addition. AOB changed in community composition and increased in abundance upon ammonium amendment in bulk soil and rhizosphere, with changes in bacterial amoA copy numbers lagging behind relative to changes in soil ammonium. In both soils, only T‐RFs corresponding to phylotypes related to Nitrosospira clade 3a underwent significant community changes. Increases in AOB abundance were generally stronger in the bulk soil than in the rhizosphere, implying significant ammonia uptake by plant roots. AOA underwent shifts in the community composition over time and fluctuated in abundance in all treatments irrespective of ammonia availability. AOB were thus considered as the main agents responsible for fertilizer ammonium oxidation, while the functions of AOA in soil N cycling remain unresolved.