Abstract
Establishment and maintenance of forage legumes on acidic soils continues to be a worldwide problem. In an attempt to develop a more rational approach to the selection of plants and bacteria, a laboratory model system was constructed using an acidic, fresh Ultisol from an old-field. The objective of the study was to evaluate this system by determining the effect of low-level liming of the soil to pHw 4.62, 4.76, 4.83, and 4.95, and rhizobial inoculation, on the establishment and functioning of the Trifolium repens, L./Rhizobium leguminosarum bv. trifolii symbiosis. The soil, as taken from the field, was low in pHw (4.65) and base saturation (45%), relatively high in Al (2.4 cmol kg1), and essentially devoid of naturalized rhizobia. For the symbiotically-grown (inoculated) plants, beneficial effects of liming to only pHw 4.83 on shoot mass, shoot N uptake, nodule number, and ARA, but not root mass and length, were detected as early as 3 weeks. Nearlinear responses to soil pH increases were found for shoot mass, shoot N uptake, nodule number, and acetylene reduction activity at 5 and, with the exception of ARA, 7 weeks. Root mass, but not length, also responded positively to liming at these later times. Soil pH and basic cation- and aluminum-associated properties were significantly (P ≤ 0.05) correlated with shoot mass and shoot N uptake. Although correlations (r) improved with time, they never exceeded 0.80, even at 7 weeks. Asymbiotically grown (NH4NO3-treated) plants gave similar shoot responses, but at different times, indicating dissimilar growth rate responses compared with the symbiotically grown plants. Rhizobial inoculum levels altered the outcome of the symbiosis significantly, indicative of a rhizobial survival limitation. Taken together, these results suggest that both partners of the symbiosis, plants and rhizobia, were affected adversely by the stressful chemical composition of the soil. More importantly, these results demonstrate the utility of the model system for studying the early (3 weeks or less) effects of low-level liming on the development of the white clover symbiosis in a near-natural, acidic Ultisol.
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Claims 11
Claim · model-written summary
Liming to pHw 4.83 benefited shoot mass, shoot N uptake, nodule number, and acetylene reduction at three weeks.
- Taxon
- WHITE CLOVER
Trifolium repenst0 - Treatment
- liming to only pHw 4.83e0
- Interactor
- Rhizobium leguminosarum bv. trifoliiRhizobium leguminosarum bv. trifoliit1symbiont
- Outcome
- shoot mass, shoot N uptake, nodule number, and ARAe0
- Direction
- beneficial effectse0
- Qualifier
- as early as 3 weekse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“For the symbiotically-grown (inoculated) plants, beneficial effects of liming to only pHw 4.83 on shoot mass, shoot N uptake, nodule number, and ARA, but not root mass and length, were detected as early as 3 weeks”
t0“WHITE CLOVER”
t1“Rhizobium leguminosarum bv. trifolii”
Claim · model-written summary
Root mass and length did not benefit from liming at three weeks.
- Taxon
- WHITE CLOVERTrifolium repenst0
- Treatment
- liminge1
- Outcome
- root mass and lengthe0
- Direction
- note0
- Qualifier
- as early as 3 weekse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“but not root mass and length, were detected as early as 3 weeks”
t0“WHITE CLOVER”
e1“For the symbiotically-grown (inoculated) plants, beneficial effects of liming to only pHw 4.83 on shoot mass, shoot N uptake, nodule number, and ARA, but not root mass and length, were detected as early as 3 weeks”
Claim · model-written summary
Shoot mass, nitrogen uptake, and nodule number increased approximately linearly with soil pH at five and seven weeks.
- Taxon
- WHITE CLOVERTrifolium repenst0
- Outcome
- shoot mass, shoot N uptake, nodule numbere0
- Direction
- increasese0
- Qualifier
- at 5 and, with the exception of ARA, 7 weekse0
- Setting
- soile0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nearlinear responses to soil pH increases were found for shoot mass, shoot N uptake, nodule number, and acetylene reduction activity at 5 and, with the exception of ARA, 7 weeks”
t0“WHITE CLOVER”
Claim · model-written summary
Acetylene reduction activity responded to increasing soil pH at five weeks but was excepted at seven weeks.
- Taxon
- WHITE CLOVERTrifolium repenst0
- Outcome
- acetylene reduction activitye0
- Direction
- increasese0
- Qualifier
- with the exception of ARA, 7 weekse0
- Setting
- soile0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nearlinear responses to soil pH increases were found for shoot mass, shoot N uptake, nodule number, and acetylene reduction activity at 5 and, with the exception of ARA, 7 weeks”
t0“WHITE CLOVER”
Claim · model-written summary
Root mass responded positively to liming at later times.
- Taxon
- WHITE CLOVERTrifolium repenst0
- Treatment
- liminge0
- Outcome
- Root masse0
- Direction
- positivelye0
- Qualifier
- at these later timese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Root mass, but not length, also responded positively to liming at these later times”
t0“WHITE CLOVER”
Claim · model-written summary
Root length did not respond to liming at later times.
- Taxon
- WHITE CLOVERTrifolium repenst0
- Treatment
- liminge0
- Outcome
- lengthe0
- Direction
- note0
- Qualifier
- at these later timese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Root mass, but not length, also responded positively to liming at these later times”
t0“WHITE CLOVER”
Claim · model-written summary
Soil chemical properties correlated significantly with shoot mass and nitrogen uptake.
- Taxon
- WHITE CLOVERTrifolium repenst0
- Outcome
- shoot mass and shoot N uptakee0
- Qualifier
- Soil pH and basic cation- and aluminum-associated propertiese0
- Setting
- Soile0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soil pH and basic cation- and aluminum-associated properties were significantly (P ≤ 0.05) correlated with shoot mass and shoot N uptake”
t0“WHITE CLOVER”
Claim · model-written summary
The soil property correlations improved with time but remained below 0.80 at seven weeks.
- Taxon
- WHITE CLOVERTrifolium repenst0
- Outcome
- correlations (r)e0
- Direction
- improvede0
- Value
- 0.80e0
- Qualifier
- even at 7 weekse0
- Setting
- soile1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Although correlations (r) improved with time, they never exceeded 0.80, even at 7 weeks”
t0“WHITE CLOVER”
e1“Nearlinear responses to soil pH increases were found for shoot mass, shoot N uptake, nodule number, and acetylene reduction activity at 5 and, with the exception of ARA, 7 weeks”
Claim · model-written summary
Asymbiotic plants had similar shoot responses at different times, indicating different growth rates.
- Taxon
- WHITE CLOVERTrifolium repenst0
- Outcome
- shoot responsese0
- Qualifier
- at different timese0
- Comparator
- symbiotically grown plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Asymbiotically grown (NH4NO3-treated) plants gave similar shoot responses, but at different times, indicating dissimilar growth rate responses compared with the symbiotically grown plants”
t0“WHITE CLOVER”
Claim · model-written summary
Rhizobial inoculum level significantly altered the outcome of symbiosis.
- Taxon
- WHITE CLOVERTrifolium repenst0
- Treatment
- Rhizobial inoculum levelse0
- Interactor
- Rhizobium leguminosarum bv. trifoliiRhizobium leguminosarum bv. trifoliit1symbiont
- Outcome
- outcome of the symbiosise0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Rhizobial inoculum levels altered the outcome of the symbiosis significantly, indicative of a rhizobial survival limitation”
t0“WHITE CLOVER”
t1“Rhizobium leguminosarum bv. trifolii”
Claim · model-written summary
The model system demonstrated utility for studying early liming effects on white clover symbiosis.
- Taxon
- white cloverTrifolium repense0
- Outcome
- utility of the model systeme0
- Value
- 3 weeks or lesse0
- Setting
- near-natural, acidic Ultisole0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“these results demonstrate the utility of the model system for studying the early (3 weeks or less) effects of low-level liming on the development of the white clover symbiosis in a near-natural, acidic Ultisol”
The same questions in other papers
lime · growth · Trifolium repens (white clover)Results differ
9 papers in the same direction as this paper · 4 in the opposite direction
- positive
- positive
- no effect
10 papers more in this group
See all 14 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.