Abstract
Abstract Leguminous plants grown in sewage sludge–amended soils can acquire nitrogen by assimilation of nitrate and ammonium from the soil solution or from atmospheric‐dinitrogen (N 2 ) fixation through association with N 2 ‐fixing bacteria. We proposed that operation of both metabolic processes could contribute to alleviate the impact of drought in sludge‐treated plants. A greenhouse experiment was conducted to evaluate the involvement of nodule metabolism in the use efficiency of water and N in sludge‐treated plants. Treatments comprised (1) plants inoculated with rhizobia and amended with sewage sludge; (2) plants inoculated with rhizobia without any amendment; and (3) noninoculated plants supplied with ammonium nitrate, each under well‐watered and drought conditions. Under drought, sludge‐treated plants had increased plant growth and higher photosynthetic and water‐use efficiencies than untreated plants. Drought stimulated nitrate reductase and GS/GOGAT activities but did not affect the activities of phosphoenolpyruvate carboxylase and malate dehydrogenase or the leghemoglobin concentration. The results suggest that under drought conditions, both N 2 fixation and nitrate assimilation in nodules of sludge‐treated plants contributed to improve plant N supply and to increase the drought tolerance of alfalfa.
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Claims 5
Claim · model-written summary
Under drought, sludge-treated alfalfa plants had increased plant growth compared with untreated plants.
- Taxon
- alfalfa
Medicago sativat0 - Treatment
- sludge-treatede1
- Outcome
- plant growthe1
- Direction
- increasede1
- Qualifier
- Under droughte1
- Comparator
- untreated plantse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“alfalfa”
e1“Under drought, sludge-treated plants had increased plant growth and higher photosynthetic and water-use efficiencies than untreated plants”
Claim · model-written summary
Under drought, sludge-treated alfalfa plants had higher photosynthetic and water-use efficiencies than untreated plants.
- Taxon
- alfalfaMedicago sativat0
- Treatment
- sludge-treatede1
- Outcome
- photosynthetic and water-use efficienciese1
- Direction
- highere1
- Qualifier
- Under droughte1
- Comparator
- untreated plantse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“alfalfa”
e1“Under drought, sludge-treated plants had increased plant growth and higher photosynthetic and water-use efficiencies than untreated plants”
Claim · model-written summary
Drought stimulated nitrate reductase and GS/GOGAT activities.
- Taxon
- alfalfaMedicago sativat0
- Treatment
- Droughte1
- Outcome
- nitrate reductase and GS/GOGAT activitiese1
- Direction
- stimulatede1
- Comparator
- well-waterede2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“alfalfa”
e1“Drought stimulated nitrate reductase and GS/GOGAT activities”
e2“each under well-watered and drought conditions”
Claim · model-written summary
Drought did not affect the activities of phosphoenolpyruvate carboxylase and malate dehydrogenase or the leghemoglobin concentration.
- Taxon
- alfalfaMedicago sativat0
- Outcome
- activities of phosphoenolpyruvate carboxylase and malate dehydrogenase or the leghemoglobin concentratione1
- Direction
- did not affecte1
- Comparator
- well-waterede2
Not reportedTreatment
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“alfalfa”
e1“did not affect the activities of phosphoenolpyruvate carboxylase and malate dehydrogenase or the leghemoglobin concentration”
e2“each under well-watered and drought conditions”
Claim · model-written summary
The authors interpret that under drought both N2 fixation and nitrate assimilation in nodules of sludge-treated plants improved plant N supply and increased drought tolerance of alfalfa.
- Taxon
- alfalfaMedicago sativae1
- Organ / stage
- nodulese1
- Outcome
- improve plant N supply and to increase the drought tolerancee1
- Qualifier
- N 2 fixation and nitrate assimilatione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“under drought conditions, both N 2 fixation and nitrate assimilation in nodules of sludge-treated plants contributed to improve plant N supply and to increase the drought tolerance of alfalfa”
The same questions in other papers
organic · growth · Medicago sativa (alfalfa)Positive and negative results
2 papers in the same direction as this paper · 2 in the opposite direction
- negative
- no effect
- positive
1 paper more in this group
See all 5 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.