Abstract
Abstract We examined the relationship between P nutrition of soybean [ Glycine max (L.) Merr. cv. ‘Davis’] and N 2 fixation by five strains of Rhizobium japonicum ranging from an ineffective (SM‐5) to a highly effective (USDA 110) symbiosis with soybean. Phosphorus at 0, 50, 125, and 400 mg P kg −1 soil (P 0 , P 50 , P 125 , P 400 ) as Ca(H 2 PO 4 ) 2 · H 2 O was applied to pots containing 2.7 kg of a P‐fixing humoxic tropohumult free of R. japonicum . Treatments consisting of + N and five strains of R. japonicum and the four P treatments were arranged in a complete factorial replicated three times. With 400 mg P kg −1 soil treatments ranked + N > USDA 110 > USDA 31> USDA 123> USDA 33>SM‐5 for shoot dry weight and accumulation of N in the shoot. There were no significant strain effects for shoot dry weight, shoot N or nodule activity at P o . Strain rankings were the same at the intermediate levels of P but differences were smaller. Although nodule number was somewhat enhanced by P, it bore no relationship to strain effectiveness and was not a factor limiting N 2 fixation at low P. Nodule dry weight and nitrogenase activities significantly increased with P additions. The concentrations of N and P in the shoot also increased with P additions. The concentrations of shoot P and N were higher in plants provided mineral N at the low and intermediate P levels than in the inoculated plants. The results show that P nutrition is important in interpreting the N 2 fixation capability of strains of Rhizobium . Synergism between P and Rhizobium inputs requires that to obtain maximal response to the application of one input necessitates employing the other at maximum levels.
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Claims 9
Claim · model-written summary
At the highest phosphorus level, shoot dry weight and shoot nitrogen ranked mineral nitrogen above USDA 110, USDA 31, USDA 123, USDA 33 and SM‐5.
- Taxon
- soybean
Glycine maxt0 - Treatment
- 400 mg P kg −1 soile0
- Outcome
- shoot dry weight and accumulation of N in the shoote0
- Direction
- rankede0
- Qualifier
- + N > USDA 110 > USDA 31> USDA 123> USDA 33>SM‐5e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“With 400 mg P kg −1 soil treatments ranked + N > USDA 110 > USDA 31> USDA 123> USDA 33>SM‐5 for shoot dry weight and accumulation of N in the shoot.”
t0“soybean [ Glycine max (L.) Merr. cv. ‘Davis’]”
t1“strains of Rhizobium japonicum”
Claim · model-written summary
At zero phosphorus, strain effects on shoot dry weight, shoot nitrogen and nodule activity were not significant.
- Taxon
- soybeanGlycine maxt0
- Treatment
- P oe0
- Outcome
- shoot dry weight, shoot N or nodule activitye0
- Direction
- no significant strain effectse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“There were no significant strain effects for shoot dry weight, shoot N or nodule activity at P o .”
t0“soybean [ Glycine max (L.) Merr. cv. ‘Davis’]”
t1“strains of Rhizobium japonicum”
Claim · model-written summary
Intermediate phosphorus levels retained the strain ranking with smaller differences.
- Taxon
- soybeanGlycine maxt0
- Treatment
- intermediate levels of Pe0
- Outcome
- Strain rankingse0
- Direction
- smallere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Strain rankings were the same at the intermediate levels of P but differences were smaller.”
t0“soybean [ Glycine max (L.) Merr. cv. ‘Davis’]”
Claim · model-written summary
Phosphorus somewhat increased nodule number.
- Taxon
- soybeanGlycine maxt0
- Treatment
- Pe0
- Outcome
- nodule numbere0
- Direction
- enhancede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Although nodule number was somewhat enhanced by P, it bore no relationship to strain effectiveness and was not a factor limiting N 2 fixation at low P.”
t0“soybean [ Glycine max (L.) Merr. cv. ‘Davis’]”
Claim · model-written summary
Nodule number was unrelated to strain effectiveness.
- Taxon
- soybeanGlycine maxt0
- Outcome
- nodule numbert1
- Direction
- no relationshipe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“it bore no relationship to strain effectiveness”
t0“soybean [ Glycine max (L.) Merr. cv. ‘Davis’]”
t1“nodule number was somewhat enhanced by P”
e1“strains of Rhizobium japonicum”
Claim · model-written summary
Phosphorus addition significantly increased nodule dry weight and nitrogenase activities.
- Taxon
- soybeanGlycine maxt0
- Treatment
- P additionse0
- Outcome
- Nodule dry weight and nitrogenase activitiese0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nodule dry weight and nitrogenase activities significantly increased with P additions.”
t0“soybean [ Glycine max (L.) Merr. cv. ‘Davis’]”
Claim · model-written summary
Phosphorus addition increased shoot nitrogen and phosphorus concentrations.
- Taxon
- soybeanGlycine maxt0
- Treatment
- P additionse0
- Outcome
- concentrations of N and P in the shoote0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The concentrations of N and P in the shoot also increased with P additions.”
t0“soybean [ Glycine max (L.) Merr. cv. ‘Davis’]”
Claim · model-written summary
Mineral nitrogen produced higher shoot phosphorus and nitrogen concentrations than inoculation at low and intermediate phosphorus.
- Taxon
- soybeanGlycine maxt0
- Treatment
- mineral Ne0
- Outcome
- concentrations of shoot P and Ne0
- Direction
- highere0
- Qualifier
- low and intermediate P levelse0
- Comparator
- inoculated plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The concentrations of shoot P and N were higher in plants provided mineral N at the low and intermediate P levels than in the inoculated plants.”
t0“soybean [ Glycine max (L.) Merr. cv. ‘Davis’]”
Claim · model-written summary
Maximal response to either phosphorus or Rhizobium input requires maximal use of the other.
- Taxon
- soybeanGlycine maxt0
- Outcome
- employing the other at maximum levelse0
RhizobiumOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Synergism between P and Rhizobium inputs requires that to obtain maximal response to the application of one input necessitates employing the other at maximum levels.”
t0“soybean [ Glycine max (L.) Merr. cv. ‘Davis’]”
The same questions in other papers
phosphorus · symbiosis · Glycine max (soybean)Positive and negative results
70 papers in the same direction as this paper · 9 in the opposite direction · 1 reporting no difference from an alternative
- positive
- positive
- positive
77 papers more in this group
See all 81 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.