• Medientyp: E-Artikel
  • Titel: Short-term responses of soil C and N fractions to tall fescue endophyte infection
  • Beteiligte: Franzluebbers, A.J.
  • Erschienen: Springer, 2006
  • Erschienen in: Plant and Soil
  • Sprache: Englisch
  • ISSN: 0032-079X; 1573-5036
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  • Beschreibung: <p>Tall fescue (Festuca arundinacea Schreb.) is naturally infected with a fungal endophyte, Neotyphodium coenophialum, which produces toxic ergot alkaloids that negatively affect herbivores and that may alter soil organic matter dynamics. A 60-week mesocosm study with a factorial arrangement of soil type (clay loam and loamy sand) and endophyte infection (with and without) was conducted to determine potential changes in soil C and N fractions. Forage and root dry-matter production were greater with than without endophyte infection, while forage C and N concentrations were unaffected. Total, particulate, mineralizable, and aggregate-associated C and N fractions increased several fold during the course of the experiment due to large rhizosphere inputs in all treatments. The fraction of total C and N in water-stable macroaggregates (&gt;0.25 mm) was initially 0.43 ± 0.10 and 0.46 ± 0.16, respectively, and increased during the course of the experiment to 0.68 ± 0.06 and 0.56 ± 0.15 when averaged across soil type and endophyte infection level as a result of organic matter cycling and deposition in this active biophysical fraction. Changes in soil C and N fractions due to endophyte infection were minimal. The lack of detectable changes in soil C and N fractions due to endophyte infection may have been a result of the overwhelming input of C from roots and/or the relatively short-term nature (60 weeks). Greater plant productivity of endophyte-infected tall fescue is likely a contributing mechanism for eventual changes in total and active C and N fractions that have been observed in long-term pastures.</p>