Soil nitrogen transformations under elevated atmospheric CO₂ and O₃ during the soybean growing season.
We investigated the influence of elevated CO(2) and O(3) on soil N cycling within the soybean growing season and across soil environments (i.e., rhizosphere and bulk soil) at the Soybean Free Air Concentration Enrichment (SoyFACE) experiment in Illinois, USA. Elevated O(3) decreased soil mineral N likely through a reduction in plant material input and increased denitrification, which was evidenced by the greater abundance of the denitrifier gene nosZ. Elevated CO(2) did not alter the parameters evaluated and both elevated CO(2) and O(3) showed no interactive effects on nitrifier and denitrifier abundance, nor on total and mineral N concentrations. These results indicate that elevated CO(2) may have limited effects on N transformations in soybean agroecosystems. However, elevated O(3) can lead to a decrease in soil N availability in both bulk and rhizosphere soils, and this likely also affects ecosystem productivity by reducing the mineralization rates of plant-derived residues.
Department of Plant Sciences, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA. isapereira@ucdavis.edu
Engil Isadora
EI
Pujol Pereira
Haegeun
H
Chung
Kate
K
Scow
Michael J
MJ
Sadowsky
Chris
C
van Kessel
Johan
J
Six
D000388:Air / Q000032:analysis*; D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001711:Biotransformation; D002245:Carbon Dioxide / Q000032:analysis* / Q000378:metabolism; D009566:Nitrates / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D010126:Ozone / Q000032:analysis* / Q000378:metabolism; D000644:Quaternary Ammonium Compounds / Q000378:metabolism; D012621:Seasons; D012987:Soil / Q000032:analysis*; D012988:Soil Microbiology; D013025:Glycine max / Q000254:growth & development / Q000378:metabolism* / Q000382:microbiology
D001426:Bacterial Proteins; D009566:Nitrates; D000644:Quaternary Ammonium Compounds; D012987:Soil; D002245:Carbon Dioxide; D010126:Ozone; D009584:Nitrogen