Ten years of elevated atmospheric carbon dioxide alters soil nitrogen transformations in a sheep-grazed pasture

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Abstract

The increasing concentration of atmospheric carbon dioxide (CO(2)) is expected to lead to enhanced competition between plants and microorganisms for the available nitrogen (N) in soil. Here, we present novel results from a 15N tracing study conducted with a sheep-grazed pasture soil that had been under 10 years of CO(2) enrichment. Our study aimed to investigate changes in process-specific gross N transformations in a soil previously exposed to an elevated atmospheric CO(2) (eCO(2)) concentration and to examine indicators for the occurrence of progressive nitrogen limitation (PNL). Our results show that the mineralization-immobilization turnover (MIT) was enhanced under eCO(2), which was driven by the mineralization of recalcitrant organic N. The retention of N in the grassland was enhanced by increased dissimilatory NO(3)- reduction to NH(4)+ (DNRA) and decreased NH(4)+ oxidation. Our results indicate that heterotrophic processes become more important under eCO(2). We conclude that higher MIT of recalcitrant organic N and enhanced N retention are mechanisms that may alleviate PNL in grazed temperate grassland.

Detaljer

Författare
  • T Rutting
  • TJ Clough
  • C Muller
  • M Lieffering
  • PCD Newton
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Geovetenskap och miljövetenskap

Nyckelord

Originalspråkengelska
Sidor (från-till)2530-2542
TidskriftGlobal Change Biology
Volym16
Utgåva nummer9
StatusPublished - 2010
PublikationskategoriForskning
Peer review utfördJa
Externt publiceradJa