The significance of below-ground fractions when considering N and C partitioning within chickpea (Cicer arietinum L.)

K. Yasmin, G. Cadisch, Elizabeth Baggs

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13 Citations (Scopus)

Abstract

The aim of this controlled environment experiment was to quantify the distribution of leaf-fed-N-15 and canopy fed-C-13 within nodulating, non-nodulating or N fertilized non-nodulating Cicer arietinum L. and in their surrounding rhizosphere soil, excluding soil + root respiration. Nodulating chickpea partitioned 32% of its total N and 27% of its total recoverable C below-ground, of which only 50% of N and 36% of C were in the clean root fraction. Non-nodulating chickpea allocated equal recoverable C but slightly less N (28%) below-ground but lost less C from plant induced below-ground respiration. The importance of this below-ground partitioning for crop systems C and N balances is highlighted by their large (45% and 33%, for N and C, respectively) contribution to the total plant derived residue (recyclable) fraction. Recovered N-15 and C-13 were greater (P < 0.05) in the outer-rhizosphere (459 A mu g N-15 and 3.2 mg C-13 core(-1)) than in the inner-rhizosphere soil (detached from roots during freeze-drying; 18 A mu g N-15 and 67 A mu g C-13 core(-1)) in relation with the relative size of these compartments. This highlights the significance of the outer-rhizosphere soil when estimating C and N budgets and quantifying rhizodeposition, and the benefit of a double (N-15, C-13) isotope approach to determine this flow against large background soil C and N pools.

Original languageEnglish
Pages (from-to)247-259
Number of pages13
JournalPlant and Soil
Volume327
Issue number1-2
DOIs
Publication statusPublished - Feb 2010

Keywords

  • Below-ground biomass
  • Cicer arietinum
  • C-13-enrichment
  • N-15-enrichment
  • Rhizosphere
  • Isotope recovery
  • Lolium-Perenne
  • Carbon Distribution
  • Nitrogen-Fixation
  • Natural-Abundance
  • Pasture Legumes
  • Soil System
  • Field Pea
  • Plant
  • N-15
  • Rhizodeposition

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