Details zur Publikation

Kategorie Textpublikation
Referenztyp Zeitschriften
DOI 10.1007/s11104-007-9519-7
Volltext Shareable Link
Titel (primär) Light affects competition for inorganic and organic nitrogen between maize and rhizosphere microorganisms
Autor Xu, X.; Stange, C.F.; Richter, A.; Wanek, W.; Kuzyakov, Y.
Quelle Plant and Soil
Erscheinungsjahr 2008
Department BOPHY
Band/Volume 304
Heft 1-2
Seite von 59
Seite bis 72
Sprache englisch
Keywords Competition; Light; Inorganic nitrogen; Organic nitrogen; Soil microorganisms; Maize; 14C; 15N; Rhizosphere
Abstract

Effects of light on the short term competition for organic and inorganic nitrogen between maize and rhizosphere microorganisms were investigated using a mixture of amino acid, ammonium and nitrate under controlled conditions. The amount and forms of N added in the three treatments was identical, but only one of the three N forms was labeled with 15N. Glycine was additionally labeled with 14C to prove its uptake by maize and incorporation into microbial biomass in an intact form. Maize out-competed microorganisms for 15 \textNO3- 15NO3 during the whole experiment under low and high light intensity. Microbial uptake of 15N and 14C was not directly influenced by the light intensity, but was indirectly related to the impact the light intensity had on the plant. More 15 \textNH4+ 15NH4+ was recovered in microbial biomass than in plants in the initial 4 h under the two light intensities, although more 15N-glycine was incorporated into microbial biomass than in plants in the initial 4 h under low light intensity. Light had a significant effect on 15 \textNO3- 15NO3 uptake by maize, but no significant effects on the uptake of 15 \textNH4+ 15NH4+ or 15N-glycine. High light intensity significantly increased plant uptake of 15 \textNO3- 15NO3 and glycine 14C. Based on 14C to 15N recovery ratios of plants, intact glycine contributed at least 13% to glycine-derived nitrogen 4 h after tracer additions, but it contributed only 0.5% to total nitrogen uptake. These findings suggest that light intensity alters the competitive relationship between maize roots and rhizosphere microorganisms and that C4 cereals such as maize are able to access small amounts of intact glycine. We conclude that roots were stronger competitor than microorganisms for inorganic N, but microorganisms out competed plants during a short period for organic N, which was mineralized into inorganic N within a few hours of application to the soil and was thereafter available for root uptake.

 

dauerhafte UFZ-Verlinkung https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=1583
Xu, X., Stange, C.F., Richter, A., Wanek, W., Kuzyakov, Y. (2008):
Light affects competition for inorganic and organic nitrogen between maize and rhizosphere microorganisms
Plant Soil 304 (1-2), 59 - 72 10.1007/s11104-007-9519-7