Abstract
ABSTRACT Decreasing fresh water availability has intensified the search for alternative rice cultivation systems with reduced water input, but most evidence suggests negative effects on growth of lowland (LL) rice cultivars. Yield in such production systems may be improved by selection of adapted aerobic ‘Han Dao’ (HD) rice cultivars. Lowland and HD rice were compared under sole nitrate or ammonium supply as well as under mixed supply of both nitrogen (N) forms during the seedling and tillering stage; pronounced differences were found in response to the supplied N form. Shoot dry mass (DM) of HD was significantly lower than that of LL under sole and predominant ammonium supply, whereas LL showed the opposite trend, with significantly lower shoot DM under sole-nitrate supply. Nitrogen concentration of LL rice under sole-nitrate supply was significantly lower compared with other treatments at tillering stage. Han Dao rice had a significantly higher potassium (K) concentration than LL rice under sole-nitrate supply, while the opposite result was observed under sole-ammonium supply. At seedling stage, the portion of N that was taken up from nitrate-N varied from 30% to 40% in HD and LL rice in treatments 75N/25A and 50N/50A, while at both growth stages, predominant ammonium supply resulted in a lower portion (20%) of nitrate-derived N in LL than in HD rice. The portion of nitrate-derived N increased at tillering stage (from 40% to 70%). These results further illustrate a synergistic effect of co-provision of nitrate and ammonium on total N fluxes compared with supply of sole nitrate or sole ammonium. It was concluded that the interaction between N form and tiller formation during early growth stages deserves strong attention for the identification of aerobic rice cultivars.
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Claims 10
Claim · model-written summary
Han Dao shoot dry mass was significantly lower than lowland rice under sole and predominant ammonium.
- Taxon
- Rice
Oryza sativat0 - Material
- HDe0
- Treatment
- sole and predominant ammonium supplye0
- Outcome
- Shoot dry mass (DM)e0
- Direction
- lowere0
- Comparator
- LLe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Shoot dry mass (DM) of HD was significantly lower than that of LL under sole and predominant ammonium supply”
t0“Rice”
Claim · model-written summary
Lowland rice shoot dry mass was significantly lower under sole nitrate.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“LL showed the opposite trend, with significantly lower shoot DM under sole-nitrate supply.”
t0“Rice”
Claim · model-written summary
Lowland rice nitrogen concentration was significantly lower with sole nitrate at tillering.
- Taxon
- riceOryza sativae0
- Material
- LL ricee0
- Organ / stage
- tillering stagee0
- Treatment
- sole-nitrate supplye0
- Outcome
- Nitrogen concentratione0
- Direction
- lowere0
- Comparator
- other treatmentse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nitrogen concentration of LL rice under sole-nitrate supply was significantly lower compared with other treatments at tillering stage.”
Claim · model-written summary
Han Dao potassium concentration exceeded lowland rice under sole nitrate.
- Taxon
- riceOryza sativae0
- Material
- Han Dao ricee0
- Treatment
- sole-nitrate supplye0
- Outcome
- potassium (K) concentratione0
- Direction
- highere0
- Comparator
- LL ricee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Han Dao rice had a significantly higher potassium (K) concentration than LL rice under sole-nitrate supply”
Claim · model-written summary
Lowland rice potassium concentration exceeded Han Dao under sole ammonium.
- Taxon
- RiceOryza sativat0
- Treatment
- sole-ammonium supplye0
- Outcome
- potassium (K) concentratione1
- Comparator
- Han Dao ricee1
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the opposite result was observed under sole-ammonium supply.”
e1“Han Dao rice had a significantly higher potassium (K) concentration than LL rice under sole-nitrate supply, while the opposite result was observed under sole-ammonium supply.”
t0“Rice”
Claim · model-written summary
Nitrate contributed 30% to 40% of nitrogen uptake at seedling stage under 75N/25A and 50N/50A.
- Taxon
- riceOryza sativae0
- Organ / stage
- seedling stagee0
- Treatment
- 75N/25A and 50N/50Ae0
- Outcome
- portion of N that was taken up from nitrate-Ne0
- Value
- 30% to 40%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At seedling stage, the portion of N that was taken up from nitrate-N varied from 30% to 40% in HD and LL rice in treatments 75N/25A and 50N/50A”
Claim · model-written summary
Predominant ammonium gave lowland rice a lower nitrate-derived nitrogen portion than Han Dao rice, at 20%.
- Taxon
- riceOryza sativae0
- Material
- LLe0
- Treatment
- predominant ammonium supplye0
- Outcome
- portion (20%) of nitrate-derived Ne0
- Direction
- lowere0
- Value
- 20%e0
- Comparator
- HD ricee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“predominant ammonium supply resulted in a lower portion (20%) of nitrate-derived N in LL than in HD rice.”
Claim · model-written summary
Nitrate-derived nitrogen rose from 40% to 70% at tillering.
- Taxon
- RiceOryza sativat0
- Organ / stage
- tillering stagee0
- Outcome
- portion of nitrate-derived Ne0
- Direction
- increasede0
- Value
- from 40% to 70%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The portion of nitrate-derived N increased at tillering stage (from 40% to 70%).”
t0“Rice”
Claim · model-written summary
Combined nitrate and ammonium supply synergistically increased total nitrogen fluxes against either sole form.
- Taxon
- RiceOryza sativat0
- Treatment
- co-provision of nitrate and ammoniume0
- Outcome
- total N fluxese0
- Direction
- synergistic effecte0
- Comparator
- supply of sole nitrate or sole ammoniume0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a synergistic effect of co-provision of nitrate and ammonium on total N fluxes compared with supply of sole nitrate or sole ammonium.”
t0“Rice”
Claim · model-written summary
The authors recommend attention to nitrogen form and tiller formation when identifying aerobic rice cultivars.
- Taxon
- riceOryza sativae0
- Organ / stage
- tiller formation during early growth stagese0
- Outcome
- deserves strong attention for the identification of aerobic rice cultivarse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the interaction between N form and tiller formation during early growth stages deserves strong attention for the identification of aerobic rice cultivars.”
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nitrogen · nutrient: content · Oryza sativa (rice)Positive and negative results
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See all 511 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.