Abstract
Photosynthetically derived carbon (C) is allocated belowground, allowing plants to obtain nutrients. However, less is known about the amount of nutrients acquired relative to the C allocated belowground, which is referred to as C efficiency for nutrient acquisition (CENA). Here, we examined how C efficiency for nitrogen (N) and phosphorus (P) acquisition varied between ryegrass ( Lolium perenne ) and clover ( Trifolium repens ) with and without P fertilization. A continuous 13 C-labeling method was applied to track belowground C allocation. Both species allocated nearly half of belowground C to rhizosphere respiration (49%), followed by root biomass (37%), and rhizodeposition (14%). With regard to N and P, CENA was higher for clover than for ryegrass, which remained higher after accounting for relatively low C costs associated with biological N 2 fixation. Phosphorus fertilization increased the C efficiency for P acquisition but decreased the C efficiency for N acquisition. A higher CENA for N and P in clover may be attributed to the greater rhizosphere priming on soil organic matter decomposition. Increased P availability with P fertilization could induce lower C allocation for P uptake but exacerbate soil N limitation, thereby making N uptake less C efficient. Overall, our study revealed that species-specific belowground C allocation and nutrient uptake efficiency depend on which nutrient is limited.
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Claims 10
Claim · model-written summary
Both species allocated 49% of belowground carbon to rhizosphere respiration.
- Taxon
- Lolium perenne and Trifolium repens
Trifolium repens
Lolium perennet0 - Outcome
- rhizosphere respiratione0
- Value
- 49%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Both species allocated nearly half of belowground C to rhizosphere respiration (49%)”
t0“Lolium perenne and Trifolium repens”
Claim · model-written summary
Both species allocated 37% of belowground carbon to root biomass.
- Taxon
- Lolium perenne and Trifolium repensTrifolium repensLolium perennet0
- Outcome
- root biomasse0
- Value
- 37%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“followed by root biomass (37%)”
e1“Both species allocated nearly half of belowground C to rhizosphere respiration”
t0“Lolium perenne and Trifolium repens”
Claim · model-written summary
Both species allocated 14% of belowground carbon to rhizodeposition.
- Taxon
- Lolium perenne and Trifolium repensTrifolium repensLolium perennet0
- Outcome
- rhizodepositione0
- Value
- 14%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“and rhizodeposition (14%)”
t0“Lolium perenne and Trifolium repens”
Claim · model-written summary
Clover had higher carbon efficiency for nitrogen acquisition than ryegrass.
TrifoliumOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“With regard to N and P, CENA was higher for clover than for ryegrass, which remained higher after accounting for relatively low C costs associated with biological N 2 fixation.”
Claim · model-written summary
Clover had higher carbon efficiency for phosphorus acquisition than ryegrass.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“With regard to N and P, CENA was higher for clover than for ryegrass, which remained higher after accounting for relatively low C costs associated with biological N 2 fixation.”
Claim · model-written summary
Phosphorus fertilization increased carbon efficiency for phosphorus acquisition.
- Taxon
- Lolium perenne and Trifolium repensTrifolium repensLolium perennet0
- Treatment
- Phosphorus fertilizatione0
- Outcome
- C efficiency for P acquisitione0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Phosphorus fertilization increased the C efficiency for P acquisition”
t0“Lolium perenne and Trifolium repens”
Claim · model-written summary
Phosphorus fertilization decreased carbon efficiency for nitrogen acquisition.
- Taxon
- Lolium perenne and Trifolium repensTrifolium repensLolium perennet0
- Treatment
- Phosphorus fertilizatione0
- Outcome
- C efficiency for N acquisitione0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Phosphorus fertilization increased the C efficiency for P acquisition but decreased the C efficiency for N acquisition.”
t0“Lolium perenne and Trifolium repens”
Claim · model-written summary
Greater rhizosphere priming may explain clover’s higher nutrient acquisition efficiency.
- Outcome
- higher CENA for N and Pe0
- Qualifier
- greater rhizosphere priming on soil organic matter decompositione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A higher CENA for N and P in clover may be attributed to the greater rhizosphere priming on soil organic matter decomposition.”
Claim · model-written summary
Phosphorus fertilization may reduce carbon allocation to phosphorus uptake.
- Taxon
- Lolium perenne and Trifolium repensTrifolium repensLolium perennet0
- Treatment
- P fertilizatione0
- Outcome
- lower C allocation for P uptakee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Increased P availability with P fertilization could induce lower C allocation for P uptake”
t0“Lolium perenne and Trifolium repens”
Claim · model-written summary
Phosphorus fertilization may exacerbate soil nitrogen limitation and make nitrogen uptake less carbon efficient.
- Taxon
- Lolium perenne and Trifolium repensTrifolium repensLolium perennet0
- Treatment
- P fertilizatione1
- Outcome
- N uptake less C efficiente0
- Qualifier
- soil N limitatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“exacerbate soil N limitation, thereby making N uptake less C efficient.”
e1“Increased P availability with P fertilization could induce lower C allocation for P uptake”
t0“Lolium perenne and Trifolium repens”
The same questions in other papers
fertilization · nutrient: content · Trifolium repens (white clover)Positive and negative results
2 papers in the same direction as this paper · 3 in the opposite direction
- no effect
- no effect
- no effect
2 papers more in this group
See all 6 papers →fertilization · nutrient: content · Lolium perenne (perennial ryegrass)Positive and negative results
11 papers in the same direction as this paper · 5 in the opposite direction
- no effect
- no effect
- negative
13 papers more in this group
See all 17 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.