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 language | English |
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Pages (from-to) | 247-259 |
Number of pages | 13 |
Journal | Plant and Soil |
Volume | 327 |
Issue number | 1-2 |
DOIs | |
Publication status | Published - 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