Abstract
Abstract High nitrogen (N) supply is required for high‐yielding soybean, but low soil temperatures in either early production systems or cool environments delay nodulation and limit biological nitrogen fixation (BNF). Because cytokinins are key signalling hormones in mediating nodule formation and our initial controlled environment experiment indicated that seed cytokinin treatment increased early BNF and total nodule area, it was used in field trials. Cytokinin was applied (seed or foliar) to two commercial soybean genotypes (DM50I17 and DM40R16) in field trials with early (September and early November) and conventional (late November) sowing dates in Argentina. In the field, DMR50I7 achieved consistent yields across sowing dates because increased BNF compensated for limited soil N uptake in early sowing dates, also leading to 25% higher nitrogen use efficiency (NUE). Surprisingly, soil N uptake was more cold‐sensitive than BNF with greater and prolonged N fixation in early sowing, perhaps through delayed nodulation, leading to improved N harvest index. Cytokinin seed treatment increased BNF (26%) in DM40R16 especially in early sowing dates. Although cytokinin improved cold tolerance of BNF, this was not explained by altered nodulation and did not increase yield. Here we show genetic differences in N supply in commercial soybean genotypes and the importance of BNF to maintain yield in early sown soybean.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by-nc. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 10
Claim · model-written summary
Cytokinin seed treatment increased biological nitrogen fixation by 26% in DM40R16, especially in early sowing.
- Taxon
- soybean
Glycine maxt0 - Material
- DM40R16e1
- Treatment
- Cytokinin seed treatmente1
- Outcome
- BNFe1
- Direction
- increasede1
- Value
- 26%e1
- Qualifier
- especially in early sowing datese1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“soybean yield and biological nitrogen fixation”
e1“Cytokinin seed treatment increased BNF (26%) in DM40R16 especially in early sowing dates”
Claim · model-written summary
Genotype DMR50I7 achieved consistent yields across sowing dates.
- Taxon
- soybeanGlycine maxt0
- Material
- DMR50I7e2
- Outcome
- yieldse2
- Qualifier
- across sowing datese2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“soybean yield and biological nitrogen fixation”
e2“In the field, DMR50I7 achieved consistent yields across sowing dates because increased BNF compensated for limited soil N uptake in early sowing dates, also leading to 25% higher nitrogen use efficiency (NUE)”
Claim · model-written summary
Increased BNF compensated for limited soil N uptake in DMR50I7, which explains its consistent yields.
- Taxon
- soybeanGlycine maxt0
- Material
- DMR50I7e2
- Outcome
- consistent yieldse2
- Qualifier
- increased BNF compensated for limited soil N uptakee2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“soybean yield and biological nitrogen fixation”
e2“In the field, DMR50I7 achieved consistent yields across sowing dates because increased BNF compensated for limited soil N uptake in early sowing dates, also leading to 25% higher nitrogen use efficiency (NUE)”
Claim · model-written summary
DMR50I7 had 25% higher nitrogen use efficiency.
- Taxon
- soybeanGlycine maxt0
- Material
- DMR50I7e2
- Outcome
- nitrogen use efficiency (NUE)e2
- Direction
- highere2
- Value
- 25%e2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“soybean yield and biological nitrogen fixation”
e2“In the field, DMR50I7 achieved consistent yields across sowing dates because increased BNF compensated for limited soil N uptake in early sowing dates, also leading to 25% higher nitrogen use efficiency (NUE)”
Claim · model-written summary
Early sowing gave greater and prolonged N fixation in soybean.
- Taxon
- soybeanGlycine maxt0
- Treatment
- early sowinge4
- Outcome
- N fixatione4
- Direction
- greatere4
- Qualifier
- prolongede4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“soybean yield and biological nitrogen fixation”
e4“with greater and prolonged N fixation in early sowing”
Claim · model-written summary
Delayed nodulation may improve the N harvest index of early-sown soybean.
- Taxon
- soybeanGlycine maxt0
- Outcome
- improved N harvest indexe5
- Qualifier
- delayed nodulatione5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“soybean yield and biological nitrogen fixation”
e5“perhaps through delayed nodulation, leading to improved N harvest index”
Claim · model-written summary
Cytokinin improved cold tolerance of biological nitrogen fixation, not explained by altered nodulation.
- Taxon
- soybeanGlycine maxt0
- Treatment
- cytokinine6
- Outcome
- cold tolerance of BNFe6
- Direction
- improvede6
- Qualifier
- this was not explained by altered nodulatione6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“soybean yield and biological nitrogen fixation”
e6“Although cytokinin improved cold tolerance of BNF, this was not explained by altered nodulation and did not increase yield”
Claim · model-written summary
Cytokinin did not increase soybean yield.
- Taxon
- soybeanGlycine maxt0
- Treatment
- cytokinine6
- Outcome
- yielde6
- Direction
- did not increasee6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“soybean yield and biological nitrogen fixation”
e6“Although cytokinin improved cold tolerance of BNF, this was not explained by altered nodulation and did not increase yield”
Claim · model-written summary
Commercial soybean genotypes differ genetically in N supply.
- Taxon
- soybeanGlycine maxt0
- Material
- commercial soybean genotypese7
- Outcome
- N supplye7
- Qualifier
- genetic differencese7
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“soybean yield and biological nitrogen fixation”
e7“Here we show genetic differences in N supply in commercial soybean genotypes and the importance of BNF to maintain yield in early sown soybean”
Claim · model-written summary
BNF is important for maintaining yield in early-sown soybean.
- Taxon
- soybeanGlycine maxt0
- Treatment
- early sowne7
- Outcome
- yielde7
- Direction
- maintaine7
- Qualifier
- importance of BNFe7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“soybean yield and biological nitrogen fixation”
e7“Here we show genetic differences in N supply in commercial soybean genotypes and the importance of BNF to maintain yield in early sown soybean”
The same questions in other papers
class · symbiosis · Glycine max (soybean)Positive and negative results
8 papers in the same direction as this paper · 2 in the opposite direction
- positive
- negative
- negative
7 papers more in this group
See all 11 papers →seed treatment · symbiosis · Glycine max (soybean)Positive and negative results
18 papers in the same direction as this paper · 4 in the opposite direction · 1 reporting no difference from an alternative
- no effect
- no effect
- negative
20 papers more in this group
See all 24 papers →class · yield · Glycine max (soybean)Positive and negative results
4 papers in the same direction as this paper · 38 in the opposite direction
- positive
- positive
- positive
39 papers more in this group
See all 43 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.