Abstract
Split nitrogen (N) application to oats delays final decisionson total application rate, which could help achieve the economic optimum fertilization rate (OptN) and reduce nitrogen losses. Later topdressing allows adjustment of fertilizer level at a stage when it is easier to predict nitrogen supply from soil. The objectives were: to investigate whether topdressing can be applied after stem elongation and to assess effects on yield and quality in different oat varieties; and to study the variation in optimum N-rate and the possibility to predict and readjust it during the growing season. In 14 field experiments conducted in Sweden 2020–2022, the effect of split nitrogen application, with topdressing at growth stage (GS) 32, GS45, or GS55–61, on yield and quality in six different oat varieties was evaluated. Late topdressing increased grain protein concentration and decreased fat content, but variety was more important for target quality. Compared with a single early application, late topdressing did not affect yield significantly. Year and site influenced yield and quality, similarly for all varieties, but had an impact on the effect N-treatment had on protein. A multiple regression analysis showed that yield at OptN and N-uptake in unfertilized plots at GS31–47, can explain the variation in OptN and thus be used to estimate OptN. Topdressing as late as at GS45–61 increased the chances both of higher protein and more accurate prediction of OptN. Therefore, recommendations for late topdressing can be preferable if there is a target for high protein or if there are incentives to use crop sensors for late and accurate adjustments of N fertilization rates between and within fields. The recommendations should not be dependent on variety.
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Claims 11
Claim · model-written summary
Late topdressing increased oat grain protein concentration.
- Taxon
- oat
Avena sativat0 - Treatment
- Late topdressinge0
- Outcome
- grain protein concentratione0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Late topdressing increased grain protein concentration and decreased fat content, but variety was more important for target quality.”
t0“oat”
Claim · model-written summary
Late topdressing decreased oat fat content.
- Taxon
- oatAvena sativat0
- Treatment
- Late topdressinge0
- Outcome
- fat contente0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Late topdressing increased grain protein concentration and decreased fat content, but variety was more important for target quality.”
t0“oat”
Claim · model-written summary
Variety mattered more than topdressing for target oat quality.
- Taxon
- oatAvena sativat0
- Material
- varietye0
- Outcome
- target qualitye0
- Direction
- more importante0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Late topdressing increased grain protein concentration and decreased fat content, but variety was more important for target quality.”
t0“oat”
Claim · model-written summary
Late topdressing did not significantly change yield versus a single early application.
- Taxon
- oatAvena sativat0
- Treatment
- late topdressinge0
- Outcome
- yielde0
- Direction
- did not affecte0
- Comparator
- a single early applicatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Compared with a single early application, late topdressing did not affect yield significantly.”
t0“oat”
Claim · model-written summary
Year and site influenced yield and quality similarly across varieties.
- Taxon
- oatAvena sativat0
- Outcome
- yield and qualitye0
- Qualifier
- similarly for all varietiese0
- Setting
- Year and sitee0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Year and site influenced yield and quality, similarly for all varieties, but had an impact on the effect N-treatment had on protein.”
t0“oat”
Claim · model-written summary
Year and site changed the nitrogen-treatment effect on protein.
- Taxon
- oatAvena sativat0
- Treatment
- N-treatmente0
- Outcome
- proteine0
- Setting
- Year and sitee0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Year and site influenced yield and quality, similarly for all varieties, but had an impact on the effect N-treatment had on protein.”
t0“oat”
Claim · model-written summary
Yield at OptN and nitrogen uptake in unfertilized plots explained variation in OptN and supported its estimation.
- Taxon
- oatAvena sativat0
- Outcome
- variation in OptNe0
- Qualifier
- yield at OptN and N-uptake in unfertilized plots at GS31–47e0
Not reportedComparatorValue
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Schema note from the model: Qualitative model result lacks a value or comparator
Verbatim
e0“A multiple regression analysis showed that yield at OptN and N-uptake in unfertilized plots at GS31–47, can explain the variation in OptN and thus be used to estimate OptN.”
t0“oat”
Claim · model-written summary
Topdressing at GS45–61 increased the chance of higher protein.
- Taxon
- oatAvena sativat0
- Treatment
- Topdressing as late as at GS45–61e0
- Outcome
- higher proteine0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Topdressing as late as at GS45–61 increased the chances both of higher protein and more accurate prediction of OptN.”
t0“oat”
Claim · model-written summary
Topdressing at GS45–61 increased the chance of more accurate OptN prediction.
- Taxon
- oatAvena sativat0
- Treatment
- Topdressing as late as at GS45–61e0
- Outcome
- more accurate prediction of OptNe0
- Direction
- increasede0
Not reportedComparatorValue
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Schema note from the model: Qualitative method result lacks a value or comparator
Verbatim
e0“Topdressing as late as at GS45–61 increased the chances both of higher protein and more accurate prediction of OptN.”
t0“oat”
Claim · model-written summary
The authors recommend late topdressing for high-protein targets or accurate sensor-guided nitrogen adjustment.
- Taxon
- oatAvena sativat0
- Outcome
- late topdressinge0
- Qualifier
- if there is a target for high protein or if there are incentives to use crop sensorse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Therefore, recommendations for late topdressing can be preferable if there is a target for high protein or if there are incentives to use crop sensors for late and accurate adjustments of N fertilization rates between and within fields.”
t0“oat”
Claim · model-written summary
The authors advise that topdressing recommendations should not depend on variety.
- Taxon
- oatAvena sativat0
- Outcome
- recommendations should not be dependent on varietye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The recommendations should not be dependent on variety.”
t0“oat”
The same questions in other papers
fertilization · quality: protein · Avena sativa (oats)Results differ
24 papers in the same direction as this paper · 3 in the opposite direction
- negative
- no effect
- no effect
24 papers more in this group
See all 28 papers →fertilization · yield · Avena sativa (oats)Positive and negative results
16 papers in the same direction as this paper · 143 reporting no difference from an alternative
- positive
- positive
- positive
156 papers more in this group
See all 160 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.