Abstract
Upland rice and dry-cultivated paddy rice have been attracted more and more attention because of limited water re- sources in China. Researches on interaction between water and nitrogen supplies for crop resistance to drought stress has become the hot topic regarding regulation on nutritional physiology. However, there is little information available on effect of nitrogen (N) nutrition on grain yield and its components of upland rice and paddy rice under different cultivation methods. The objective of this study was to evaluate the difference between upland rice and paddy rice and interaction between cultivation methods and N levels. One upland rice cultivar Zhonghan 3 (japonica) and one paddy rice cultivar Yangjing 9538 (japonica) were grown under moist cultivation (MC, control) or bare dry-cultivation (DC) with three N levels, low amount of N (LN, 100 kg ha-1), normal amount of N (NN, 200 kg ha-1), and high amount of N (HN, 300 kg ha-1). The results showed that, compared with NN, the grain yield under HN was lower for both upland and paddy rice under DC and for paddy rice under MC, whereas higher for upland rice under MC. With the increase in N levels, upland rice and paddy rice showed higher productive tillers, more or fewer spikelets per panicle, lower percentage of ripened grains under two cultivation methods. However, the percentage of ripened grains was reduced more for paddy rice than for upland rice. There was no significant difference in 1 000-grain weight for upland rice among three N levels, whereas grain weight was reduced with the increase in N levels. Compared with MC, DC showed no significant difference in grain weight for upland rice, whereas a significant decrease for paddy rice. DC significantly increased the percentage of ripened grains for both upland and paddy rice, and that were more for upland rice than for paddy rice. Compared with paddy rice, upland rice showed less number of adventitious roots, lower nitrogen absorption ability and lower productive tillering ability, fewer pani- cles, fewer spikelets per panicle and lower grain yield. However, upland rice exhibited quicker increase in adventitious roots and slower declining in leaf nitrogen content from jointing to heading, and a faster declining speed in chlorophyll content (SPAD value) after flowering. Also, upland rice had less negative response to water stress and more positive response to N. The results suggest that the response to cultivation methods and N levels varies largely between upland rice and paddy rice. The approaches to in- crease the grain yield of both paddy and upland rice were discussed.
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Claims 15
Claim · model-written summary
High N lowered grain yield relative to normal N in both rice types under dry cultivation and paddy rice under moist cultivation.
Verbatim
e0“compared with NN, the grain yield under HN was lower for both upland and paddy rice under DC and for paddy rice under MC”
Claim · model-written summary
High N raised upland rice grain yield under moist cultivation.
- Taxon
- upland rice
Oryza sativae0 - Direction
- highere0
Not reportedTreatmentComparatorOutcome
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“whereas higher for upland rice under MC”
Claim · model-written summary
Increasing N raised productive tillers in both rice types.
- Taxon
- upland riceOryza sativae0
- Treatment
- increase in N levelse0
- Outcome
- productive tillerse0
- Direction
- highere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“With the increase in N levels, upland rice and paddy rice showed higher productive tillers”
Claim · model-written summary
Increasing N changed spikelets per panicle variably.
- Taxon
- upland riceOryza sativat0
- Outcome
- spikelets per paniclee0
- Direction
- more or fewere0
Not reportedTreatmentComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“more or fewer spikelets per panicle”
t0“Upland Rice”
Claim · model-written summary
Increasing N lowered ripened grain percentage in both rice types, more in paddy rice.
Not reportedTreatment
Verbatim
e0“lower percentage of ripened grains under two cultivation methods. However, the percentage of ripened grains was reduced more for paddy rice than for upland rice.”
Claim · model-written summary
Upland rice grain weight did not differ significantly across N levels.
- Taxon
- upland riceOryza sativae0
- Treatment
- three N levelse0
- Outcome
- 1 000-grain weighte0
- Direction
- no significant differencee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“There was no significant difference in 1 000-grain weight for upland rice among three N levels”
Claim · model-written summary
Grain weight declined as N increased.
Not reportedComparator
Verbatim
e0“grain weight was reduced with the increase in N levels”
t0“paddy rice”
Claim · model-written summary
Dry cultivation did not significantly change upland rice grain weight.
- Taxon
- upland riceOryza sativae0
- Treatment
- DCe0
- Outcome
- grain weighte0
- Direction
- no significant differencee0
- Comparator
- MCe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Compared with MC, DC showed no significant difference in grain weight for upland rice”
Claim · model-written summary
Dry cultivation significantly decreased paddy rice grain weight.
Not reportedTreatmentComparatorOutcome
Verbatim
e0“whereas a significant decrease for paddy rice”
Claim · model-written summary
Dry cultivation increased ripened grain percentage in both rice types, more in upland rice.
- Taxon
- upland riceOryza sativae0
- Treatment
- DCe0
- Outcome
- percentage of ripened grainse0
- Direction
- increasede0
- Comparator
- paddy ricee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“DC significantly increased the percentage of ripened grains for both upland and paddy rice, and that were more for upland rice than for paddy rice.”
Claim · model-written summary
Upland rice had fewer adventitious roots and weaker nitrogen absorption and productive tillering than paddy rice.
- Taxon
- upland riceOryza sativae0
- Outcome
- less number of adventitious roots, lower nitrogen absorption ability and lower productive tillering abilitye0
- Comparator
- paddy ricee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Compared with paddy rice, upland rice showed less number of adventitious roots, lower nitrogen absorption ability and lower productive tillering ability”
Claim · model-written summary
Upland rice had fewer panicles and spikelets and lower yield than paddy rice.
- Taxon
- upland riceOryza sativat0
- Outcome
- fewer pani- cles, fewer spikelets per panicle and lower grain yielde0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“fewer pani- cles, fewer spikelets per panicle and lower grain yield”
t0“Upland Rice”
Claim · model-written summary
Upland rice showed a quicker rise in adventitious roots and slower decline in leaf nitrogen from jointing to heading.
- Taxon
- upland riceOryza sativae0
- Organ / stage
- from jointing to headinge0
- Outcome
- quicker increase in adventitious roots and slower declining in leaf nitrogen contente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“upland rice exhibited quicker increase in adventitious roots and slower declining in leaf nitrogen content from jointing to heading”
Claim · model-written summary
Upland rice showed faster postflowering chlorophyll decline.
- Taxon
- upland riceOryza sativat0
- Organ / stage
- after floweringe0
- Outcome
- chlorophyll content (SPAD value)e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a faster declining speed in chlorophyll content (SPAD value) after flowering”
t0“Upland Rice”
Claim · model-written summary
Upland rice had less negative response to water stress and more positive response to N.
- Taxon
- upland riceOryza sativae0
- Outcome
- less negative response to water stress and more positive response to Ne0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“upland rice had less negative response to water stress and more positive response to N”
The same questions in other papers
nitrogen · yield · Oryza sativa (rice)Positive and negative results
1,802 papers in the same direction as this paper · 193 in the opposite direction · 49 reporting no difference from an alternative
- negative
- negative
- negative
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