Abstract
Core Ideas Nitrogen availability and fertilization can increase sunflower see yield. Nitrogen fertilization may decrease oil concentration of oilseed sunflower. Nitrogen fertilization increases sunflower lodging risk in windy regions. The N and P recommendations for sunflowers growers in North Dakota have not been changed in 30 yr. Twenty‐two N and P rate experiments were conducted during 2014 and 2015. The objective was to determine the response of seed yield, oil concentration, and lodging to available N and P. In 2014 studies were a randomized complete block split plot with N rate as main plots and P rate as subplots. Nitrogen was applied at rates of 0, 45, 90, 134, 179, and 224 kg N ha −1 . Phosphorus was applied to establish P rates of 0, 13, 26, and 39 kg P ha −1 . In 2015, the field design included only 0 and 26 kg P ha −1 . Experiments were taken to yield and lodging was recorded at harvest. Oil seed sunflower (17 experimental locations) was also analyzed for oil concentration. The N response of sunflower seed yield was quadratic. Increased N rate resulted in lower oil concentration in half of the oilseed experiments. Increased N rate was linearly related to increasing lodging at several sites. Phosphate fertilization had little effect on seed yield, oil concentration, and lodging, despite many of the sites having soil P levels considered ‘low’. Future N rate recommendations should be based on seed yield response with increasing N and oil concentration reduction with increasing N for oilseed sunflower. A limit to maximum N rate should also be considered because of the lodging risk in this wind‐plagued region.
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Claims 6
Claim · model-written summary
Sunflower seed yield showed a quadratic response to nitrogen.
- Taxon
- sunflower
Helianthus annuuse0 - Treatment
- Ne0
- Outcome
- sunflower seed yielde0
- Qualifier
- quadratice0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The N response of sunflower seed yield was quadratic.”
Claim · model-written summary
In half the oilseed experiments increased nitrogen lowered oil concentration.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- Increased N ratee0
- Outcome
- oil concentratione0
- Direction
- lowere0
- Qualifier
- in half of the oilseed experimentse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Increased N rate resulted in lower oil concentration in half of the oilseed experiments.”
t0“Sunflower”
Claim · model-written summary
Increasing nitrogen was linearly related to more lodging at several sites.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- Increased N ratee0
- Outcome
- lodginge0
- Direction
- increasinge0
- Qualifier
- at several sitese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Increased N rate was linearly related to increasing lodging at several sites.”
t0“Sunflower”
Claim · model-written summary
Phosphate fertilization had little effect on seed yield, oil concentration and lodging.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- Phosphate fertilizatione0
- Outcome
- seed yield, oil concentration, and lodginge0
- Direction
- little effecte0
- Qualifier
- despite many of the sites having soil P levels considered ‘low’e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Phosphate fertilization had little effect on seed yield, oil concentration, and lodging, despite many of the sites having soil P levels considered ‘low’.”
t0“Sunflower”
Claim · model-written summary
Authors recommend basing future nitrogen rates on seed yield gains and oil concentration reductions.
- Taxon
- sunflowerHelianthus annuuse0
- Outcome
- Future N rate recommendationse0
- Qualifier
- seed yield response with increasing N and oil concentration reduction with increasing Ne0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Future N rate recommendations should be based on seed yield response with increasing N and oil concentration reduction with increasing N for oilseed sunflower.”
Claim · model-written summary
Authors advise considering a maximum nitrogen rate because of lodging risk.
- Taxon
- SunflowerHelianthus annuust0
- Outcome
- A limit to maximum N ratee0
- Qualifier
- because of the lodging risk in this wind‐plagued regione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A limit to maximum N rate should also be considered because of the lodging risk in this wind‐plagued region.”
t0“Sunflower”
The same questions in other papers
nitrogen · quality: oil · Helianthus annuus (common sunflower)Results differ
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- positive
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12 papers in the same direction as this paper · 76 in the opposite direction
- positive
- no effect
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See all 89 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.