Abstract
Rice ( Oryza sativa L.) growers sometimes have yield losses because of inadequate rice population densities. One way to partially alleviate the yield loss resulting from inadequate plant populations may be to increase early season N fertilization. The objective of this study was to determine whether the N response differed among significantly different plant populations of the two predominant cultivars grown in the South. Field experiments were conducted in 1987 and 1988 at Keiser, AR. The treatments were cultivar (‘Lemont’ and ‘Newbonnet’), preflood N rates (0, 40, 70, and 100 lb/acre), and seeding rates (5, 40, and 125 seeds/sq ft). Grain yield increased linearly with N increases at the inadequate population density (5 seeds/sq ft seeding rate with a mean population of 3.1 plants/sq ft). At near‐optimum (40 seeds/sq ft, 21.8 plants/sq ft) and excessive populations (125 seeds/sq ft, 67.8 plants/sq ft) there was a large yield increase in response to the first N increment (0 to 40 lb N/acre) and smaller increases in response to the next two N increments (40 to 70, and 70 to 100 lb N/acre). Yield component responses to N varied with population: at the inadequate population, increases were the result of greater tillering; at the near‐optimum population, yield increases were the result of a combination of increases in tillering and in the number of seeds per panicle; and at the excessive plant population, yield increases were primarily the result of increased numbers of seeds per panicle. It is recommended that inadequate rice populations should have substantially greater early season N rates.
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Claims 7
Claim · model-written summary
At inadequate rice density, grain yield increased linearly with nitrogen.
- Taxon
- Rice
Oryza sativat0 - Treatment
- N increasese0
- Outcome
- Grain yielde0
- Direction
- increasede0
- Qualifier
- inadequate population density (5 seeds/sq ft seeding rate with a mean population of 3.1 plants/sq ft)e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grain yield increased linearly with N increases at the inadequate population density (5 seeds/sq ft seeding rate with a mean population of 3.1 plants/sq ft).”
t0“Rice”
Claim · model-written summary
At near-optimum and excessive populations the first nitrogen increment produced a large yield increase.
- Taxon
- RiceOryza sativat0
- Treatment
- first N increment (0 to 40 lb N/acre)e0
- Outcome
- yielde0
- Direction
- increasee0
- Qualifier
- near‐optimum (40 seeds/sq ft, 21.8 plants/sq ft) and excessive populations (125 seeds/sq ft, 67.8 plants/sq ft)e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At near‐optimum (40 seeds/sq ft, 21.8 plants/sq ft) and excessive populations (125 seeds/sq ft, 67.8 plants/sq ft) there was a large yield increase in response to the first N increment (0 to 40 lb N/acre)”
t0“Rice”
Claim · model-written summary
At near-optimum and excessive populations later nitrogen increments gave smaller yield increases.
- Taxon
- RiceOryza sativat0
- Treatment
- next two N increments (40 to 70, and 70 to 100 lb N/acre)e0
- Outcome
- increasese0
- Direction
- increasese0
- Qualifier
- smallere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“smaller increases in response to the next two N increments (40 to 70, and 70 to 100 lb N/acre)”
t0“Rice Plant Population Density Effect on Early‐Season Nitrogen Requirement”
Claim · model-written summary
At inadequate density nitrogen yield gains resulted from greater tillering.
- Taxon
- RiceOryza sativat0
- Organ / stage
- tilleringe0
- Outcome
- increasese0
- Qualifier
- greater tilleringe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“at the inadequate population, increases were the result of greater tillering”
t0“Rice”
Claim · model-written summary
At near-optimum density nitrogen yield gains reflected more tillering and seeds per panicle.
- Taxon
- RiceOryza sativat0
- Organ / stage
- tilleringe0
- Outcome
- yield increasese0
- Qualifier
- increases in tillering and in the number of seeds per paniclee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“at the near‐optimum population, yield increases were the result of a combination of increases in tillering and in the number of seeds per panicle”
t0“Rice”
Claim · model-written summary
At excessive density yield gains primarily reflected more seeds per panicle.
- Taxon
- RiceOryza sativat0
- Organ / stage
- paniclee0
- Outcome
- yield increasese0
- Qualifier
- increased numbers of seeds per paniclee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“at the excessive plant population, yield increases were primarily the result of increased numbers of seeds per panicle”
t0“Rice”
Claim · model-written summary
The authors recommend greater early nitrogen rates for inadequate rice populations.
- Taxon
- riceOryza sativae0
- Outcome
- substantially greater early season N ratese0
- Direction
- greatere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“It is recommended that inadequate rice populations should have substantially greater early season N rates.”
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
- no effect
- positive
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See all 2,045 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.