Abstract
The decomposition processes of Azolla in water and soil in relation to the availability of Azolla-nitrogen to rice plants were determined using 15N as a tracer. Among the 3 species of Azolla (8 strains) used in this experiment, Azolla pinnata from Malaysia attained the highest biomass and supplied the largest amount of decaying materials to water. Azolla mexicana showed intermediate characteristics in growth and detachment of old tissues. Azolla filiculoides grew very slowly and developed symptoms of decay at early stages. The amount of ammonium excreted from Azolla into the water was negligible. When Azolla was incorporated into soil, A. pinnata underwent the most active mineralization process, followed by A. filiculoides and A. mexicana. Among the A. pinnata strains, the one from Malaysia released the largest amount of ammonium into soils. Within 6 weeks about two thirds of the nitrogen were lost from Azolla that was placed on the surface of flooded soils. Losses were about 30% from Azolla that was incorporated. Rice plants grown in a pot absorbed 50% 15N-labeled Azolla-nitrogen incorporated at the time of transplanting. When Azolla was kept on the surface of water, less than 10% of its nitrogen was available to the rice plant. In the field trial, larger amounts of Azolla-nitrogen were available to rice when Azolla was incorporated than when it was placed on the soil surface. However, the availability following incorporation (12-27%) was much lower than pots. A later application (78 days after transplanting) resulted in a higher contribution of Azolla-nitrogen to grain-nitrogen than an earlier application (30 or 53 days after transplanting).
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Claims 15
Claim · model-written summary
Azolla pinnata from Malaysia attained the highest biomass among the three Azolla species.
- Taxon
- Azolla pinnata
Azolla pinnatae1 - Outcome
- biomasse1
- Direction
- higheste1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Azolla pinnata from Malaysia attained the highest biomass and supplied the largest amount of decaying materials to water”
Claim · model-written summary
Azolla pinnata from Malaysia supplied the largest amount of decaying materials to water.
- Taxon
- Azolla pinnataAzolla pinnatae1
- Outcome
- amount of decaying materialse1
- Direction
- largeste1
- Qualifier
- to watere1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Azolla pinnata from Malaysia attained the highest biomass and supplied the largest amount of decaying materials to water”
Claim · model-written summary
Azolla mexicana showed intermediate characteristics in growth and in detachment of old tissues.
- Taxon
- Azolla mexicanaAzolla mexicanae1
- Outcome
- characteristics in growth and detachment of old tissuese1
- Direction
- intermediatee1
Verbatim
e1“Azolla mexicana showed intermediate characteristics in growth and detachment of old tissues”
Claim · model-written summary
Azolla filiculoides grew very slowly.
- Taxon
- Azolla filiculoides
Azolla filiculoidese1 - Outcome
- grewe1
- Direction
- very slowlye1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Azolla filiculoides grew very slowly”
Claim · model-written summary
Azolla filiculoides developed symptoms of decay at early stages.
- Taxon
- Azolla filiculoidesAzolla filiculoidese1
- Outcome
- symptoms of decaye1
- Qualifier
- at early stagese1
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Azolla filiculoides grew very slowly and developed symptoms of decay at early stages”
Claim · model-written summary
The amount of ammonium excreted from Azolla into the water was negligible.
AzollaOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“The amount of ammonium excreted from Azolla into the water was negligible”
Claim · model-written summary
When Azolla was incorporated into soil, A. pinnata had the most active mineralization process, ahead of A. filiculoides and A. mexicana.
- Taxon
- A. pinnataAzolla pinnatae1
- Treatment
- incorporated into soile1
- Outcome
- mineralization processe1
- Direction
- most activee1
- Comparator
- A. filiculoides and A. mexicanae1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“When Azolla was incorporated into soil, A. pinnata underwent the most active mineralization process, followed by A. filiculoides and A. mexicana”
Claim · model-written summary
Among the A. pinnata strains, the one from Malaysia released the largest amount of ammonium into soils.
- Taxon
- A. pinnataAzolla pinnatae1
- Material
- the one from Malaysiae1
- Outcome
- amount of ammoniume1
- Direction
- largeste1
- Qualifier
- into soilse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Among the A. pinnata strains, the one from Malaysia released the largest amount of ammonium into soils”
Claim · model-written summary
Within 6 weeks about two thirds of the nitrogen were lost from Azolla placed on the surface of flooded soils.
- Treatment
- placed on the surface of flooded soilse1
- Outcome
- nitrogene1
- Direction
- loste1
- Value
- about two thirdse1
- Qualifier
- Within 6 weekse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Within 6 weeks about two thirds of the nitrogen were lost from Azolla that was placed on the surface of flooded soils”
Claim · model-written summary
Losses of about 30% of nitrogen occurred from incorporated Azolla.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Losses were about 30% from Azolla that was incorporated”
Claim · model-written summary
When Azolla was kept on the surface of water, less than 10% of its nitrogen was available to the rice plant.
- Taxon
- rice plant
Oryza sativae1 - Treatment
- kept on the surface of watere1
- Outcome
- nitrogen was availablee1
- Value
- less than 10%e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“When Azolla was kept on the surface of water, less than 10% of its nitrogen was available to the rice plant”
Claim · model-written summary
Rice plants grown in a pot absorbed 50% of 15N-labeled Azolla-nitrogen incorporated at transplanting.
- Taxon
- Rice plantsOryza sativae1
- Treatment
- incorporated at the time of transplantinge1
- Outcome
- absorbede1
- Value
- 50%e1
- Setting
- in a pote1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Rice plants grown in a pot absorbed 50% 15N-labeled Azolla-nitrogen incorporated at the time of transplanting”
Claim · model-written summary
In the field trial, larger amounts of Azolla-nitrogen were available to rice when Azolla was incorporated than when it was placed on the soil surface.
- Taxon
- riceOryza sativae1
- Treatment
- incorporatede1
- Outcome
- Azolla-nitrogen were availablee1
- Direction
- larger amountse1
- Comparator
- placed on the soil surfacee1
- Setting
- field triale1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“In the field trial, larger amounts of Azolla-nitrogen were available to rice when Azolla was incorporated than when it was placed on the soil surface”
Claim · model-written summary
In the field trial, availability of Azolla-nitrogen after incorporation (12-27%) was much lower than in pots.
- Taxon
- riceOryza sativae2
- Treatment
- incorporatione1
- Outcome
- availabilitye1
- Direction
- much lowere1
- Value
- 12-27%e1
- Comparator
- potse1
- Setting
- field triale3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“However, the availability following incorporation (12-27%) was much lower than pots”
e2“larger amounts of Azolla-nitrogen were available to rice”
e3“In the field trial”
Claim · model-written summary
A later application at 78 days after transplanting gave a higher contribution of Azolla-nitrogen to grain-nitrogen than an earlier application at 30 or 53 days.
- Taxon
- riceOryza sativae2
- Organ / stage
- graine1
- Treatment
- later application (78 days after transplanting)e1
- Outcome
- contribution of Azolla-nitrogen to grain-nitrogene1
- Direction
- highere1
- Comparator
- earlier application (30 or 53 days after transplanting)e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“A later application (78 days after transplanting) resulted in a higher contribution of Azolla-nitrogen to grain-nitrogen than an earlier application (30 or 53 days after transplanting)”
e2“larger amounts of Azolla-nitrogen were available to rice”
The same questions in other papers
transplanting · organism · Oryza sativa (rice)Positive and negative results
31 papers in the same direction as this paper · 3 in the opposite direction
- negative
- no effect
- negative
31 papers more in this group
See all 35 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.