Abstract
Nitrogen deficiency is one of the most important nutritional disorders in lowland rice producing areas around the world. Nitrogen fertilizer recommendations for lowland rice (Oryza sativa L.) varieties grown on Inceptisols are limited. The objective of this study was to evaluate the response of lowland rice (cv. Metica 1) to added N and to determine N use efficiency and nutrient accumulation during the crop growth cycle. A field experiment was conducted during 3 consecutive years in the central part of Brazil on a Haplaquept Inceptisol. Nitrogen levels used were 0, 30, 60, 90, 120,150, 180, and 210 kg N ha−1. Nitrogen fertilization significantly increased dry matter and grain yield. Ninty percent of the maximum grain yield (6400 kg ha−1) was obtained with the application of 120 kg N ha−1 in the first year of experimentation. In the second and third years, 90% of the maximum yields (6345 and 5203 kg ha−1) were obtained at 90 and 78 kg N ha−1, respectively. Yield components were also significantly affected by N treatments. Among yield components, panicle length and panicle number m 2 had highest correlations with grain yield (r=0.70** and 0.78**); maximum grain yield across the 3 years was achieved at about 583 panicles m 2. Dry matter production and grain yield at the highest N level (210 kg N ha−1) across the 3 years were 9423 and 6389 kg ha−1, respectively. At this grain + straw yield, the rice crop accumulated 139 kg N, 26 kg P, 218 kg K, 36 kg Ca, 24 kg Mg, 850 g Zn, 5971 g Mn, 125 g Cu, 4629 g Fe, and 104 g B. Nitrogen use efficiency defined in several ways, decreased with increasing N rates. Agronomic efficiency across 3 yeras averaged over N rates, was 23 kg of grain produced per kg of N applied. Physiological efficiency was 146 kg biological yield (grain + straw) produced per kg of N accumulated across the 3 year and N rates. Average agrophysiological efficiency was 63 kg grain produced per kg of N accumulated in the grains plus + straw. Apparent N recovery efficiency was 39% across the 3 years and N rates. Average nitrogen utilization efficiency was 58 kg of grain produced per kg N utilized by the rice crop. Soil pH and calcium concentration in the soil decreased significantly at higher N rates, whereas, soil Al3+ level was significantly increased after the harvest of the third rice crop.
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Claims 20
Claim · model-written summary
Nitrogen fertilization significantly increased rice dry matter.
Not reportedComparator
Verbatim
e0“Nitrogen fertilization significantly increased dry matter and grain yield.”
t0“LOWLAND RICE”
Claim · model-written summary
Nitrogen fertilization significantly increased grain yield.
Not reportedComparator
Verbatim
e0“Nitrogen fertilization significantly increased dry matter and grain yield.”
t0“LOWLAND RICE”
Claim · model-written summary
In year one, 120 kg N ha−1 produced 90% of maximum grain yield, 6400 kg ha−1.
Verbatim
e0“Ninty percent of the maximum grain yield (6400 kg ha−1) was obtained with the application of 120 kg N ha−1 in the first year of experimentation.”
t0“LOWLAND RICE”
Claim · model-written summary
In year two, 90 kg N ha−1 produced 90% of maximum yield, 6345 kg ha−1.
Verbatim
e0“In the second and third years, 90% of the maximum yields (6345 and 5203 kg ha−1) were obtained at 90 and 78 kg N ha−1, respectively.”
t0“LOWLAND RICE”
Claim · model-written summary
Nitrogen treatments significantly affected rice yield components.
Verbatim
e0“Yield components were also significantly affected by N treatments.”
t0“LOWLAND RICE”
Claim · model-written summary
Panicle length correlated with grain yield at r=0.70.
Not reportedDirection
Verbatim
e0“panicle length and panicle number m 2 had highest correlations with grain yield (r=0.70** and 0.78**)”
t0“LOWLAND RICE”
Claim · model-written summary
Panicle number correlated with grain yield at r=0.78.
Not reportedDirection
Verbatim
e0“panicle length and panicle number m 2 had highest correlations with grain yield (r=0.70** and 0.78**)”
t0“LOWLAND RICE”
Claim · model-written summary
Maximum grain yield across three years occurred near 583 panicles per square metre.
Verbatim
e0“maximum grain yield across the 3 years was achieved at about 583 panicles m 2.”
t0“LOWLAND RICE”
Claim · model-written summary
At the highest nitrogen rate, dry matter production across three years was 9423 kg ha−1.
Verbatim
e0“Dry matter production and grain yield at the highest N level (210 kg N ha−1) across the 3 years were 9423 and 6389 kg ha−1, respectively.”
t0“LOWLAND RICE”
Claim · model-written summary
At the highest nitrogen rate, grain yield across three years was 6389 kg ha−1.
Verbatim
e0“Dry matter production and grain yield at the highest N level (210 kg N ha−1) across the 3 years were 9423 and 6389 kg ha−1, respectively.”
t0“LOWLAND RICE”
Claim · model-written summary
Rice accumulated the reported N, P and K quantities at the reported yield.
- Taxon
- rice crop
Oryza sativae0 - Outcome
- accumulated 139 kg N, 26 kg P, 218 kg Ke0
- Value
- 139 kg Ne0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the rice crop accumulated 139 kg N, 26 kg P, 218 kg K, 36 kg Ca, 24 kg Mg, 850 g Zn, 5971 g Mn, 125 g Cu, 4629 g Fe, and 104 g B.”
Claim · model-written summary
Rice accumulated the reported Ca, Mg and Zn quantities.
- Taxon
- rice cropOryza sativae0
- Outcome
- 36 kg Ca, 24 kg Mg, 850 g Zne0
- Value
- 36 kg Cae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the rice crop accumulated 139 kg N, 26 kg P, 218 kg K, 36 kg Ca, 24 kg Mg, 850 g Zn, 5971 g Mn, 125 g Cu, 4629 g Fe, and 104 g B.”
Claim · model-written summary
Rice accumulated the reported Mn, Cu and Fe quantities.
- Taxon
- rice cropOryza sativae0
- Outcome
- 5971 g Mn, 125 g Cu, 4629 g Fee0
- Value
- 5971 g Mne0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the rice crop accumulated 139 kg N, 26 kg P, 218 kg K, 36 kg Ca, 24 kg Mg, 850 g Zn, 5971 g Mn, 125 g Cu, 4629 g Fe, and 104 g B.”
Claim · model-written summary
Rice accumulated 104 g B.
- Taxon
- rice cropOryza sativae0
- Outcome
- accumulatede0
- Value
- 104 g Be0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the rice crop accumulated 139 kg N, 26 kg P, 218 kg K, 36 kg Ca, 24 kg Mg, 850 g Zn, 5971 g Mn, 125 g Cu, 4629 g Fe, and 104 g B.”
Claim · model-written summary
Nitrogen use efficiency decreased as nitrogen rate rose.
Verbatim
e0“Nitrogen use efficiency defined in several ways, decreased with increasing N rates.”
t0“LOWLAND RICE”
Claim · model-written summary
Average agronomic efficiency was 23 kg grain per kg nitrogen applied.
Verbatim
e0“Agronomic efficiency across 3 yeras averaged over N rates, was 23 kg of grain produced per kg of N applied.”
t0“LOWLAND RICE”
Claim · model-written summary
Physiological efficiency was 146 kg biological yield per kg accumulated nitrogen.
Verbatim
e0“Physiological efficiency was 146 kg biological yield (grain + straw) produced per kg of N accumulated across the 3 year and N rates.”
t0“LOWLAND RICE”
Claim · model-written summary
Average agrophysiological efficiency was 63 kg grain per kg accumulated nitrogen.
Verbatim
e0“Average agrophysiological efficiency was 63 kg grain produced per kg of N accumulated in the grains plus + straw.”
t0“LOWLAND RICE”
Claim · model-written summary
Apparent nitrogen recovery was 39%; nitrogen utilization averaged 58 kg grain per kg nitrogen used.
- Taxon
- rice cropOryza sativae0
- Outcome
- Apparent N recovery efficiencye0
- Value
- 39%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Apparent N recovery efficiency was 39% across the 3 years and N rates. Average nitrogen utilization efficiency was 58 kg of grain produced per kg N utilized by the rice crop.”
Claim · model-written summary
Higher nitrogen rates lowered soil pH and calcium and raised Al3+ after the third crop.
- Taxon
- rice cropOryza sativae0
- Treatment
- higher N ratese0
- Outcome
- Soil pH and calcium concentration in the soile0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soil pH and calcium concentration in the soil decreased significantly at higher N rates, whereas, soil Al3+ level was significantly increased after the harvest of the third rice crop.”
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fertilization · growth · Oryza sativa (rice)Positive and negative results
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- no effect
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3,182 papers in the same direction as this paper · 207 in the opposite direction · 65 reporting no difference from an alternative
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See all 3,455 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.