Abstract
Limitations in nutrient availability apparently can restrict plant response to CO 2 enrichment; however, the alterations in physiological processes associated with such restrictions have not been defined. This experiment was conducted to investigate certain physiological responses of N‐limited soybean [ Glycine max (L.) Merr. cv. Lee] plants growing in a CO 2 enriched environment and to examine their role in determining growth and yield. The nonnodulating soybean plants were grown to maturity in controlled environment chambers at 350 or 700 μL L −1 CO 2 and at 0.05, 1.0, 2.5, 5.0, or 10.0 m M KNO − 3 supplied in nutrient solution. Substantial increases in whole‐plant growth and seed yield occurred in both CO 2 treatments with increasing nitrate levels; the increases were greater, however, at high CO 2 . At all NO − 3 levels except the lowest, exposure to high CO 2 resulted in increased total leaf area, mean net assimilation rate, NO − 3 uptake, and N utilization efficiency. Increased NO − 3 uptake was associated with larger root systems, as uptake per unit of root mass was lower than controls. Carbon dioxide enrichment had little effect on dry matter partitioning among plant parts or harvest index. Alterations in partitioning were related to differences in NO − 3 supply. The results suggest that atmospheric CO 2 enrichment can stimulate seed yield of soybean even when the availability of N in the rhizosphere is limited.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. 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 9
Claim · model-written summary
Whole-plant growth and seed yield increased in both CO2 treatments with increasing nitrate levels.
- Taxon
- soybean
Glycine maxe5 - Treatment
- increasing nitrate levelse0
- Outcome
- seed yielde0
- Direction
- increasese0
- Setting
- controlled environment chamberse5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Substantial increases in whole‐plant growth and seed yield occurred in both CO 2 treatments with increasing nitrate levels; the increases were greater, however, at high CO 2”
e5“The nonnodulating soybean plants were grown to maturity in controlled environment chambers”
Claim · model-written summary
The seed yield increase with nitrate was greater at high CO2.
- Taxon
- soybeanGlycine maxe5
- Treatment
- high CO 2e0
- Outcome
- seed yielde0
- Direction
- greatere0
- Setting
- controlled environment chamberse5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Substantial increases in whole‐plant growth and seed yield occurred in both CO 2 treatments with increasing nitrate levels; the increases were greater, however, at high CO 2”
e5“The nonnodulating soybean plants were grown to maturity in controlled environment chambers”
Claim · model-written summary
High CO2 increased total leaf area and mean net assimilation rate of soybean at all nitrate levels except the lowest.
- Taxon
- soybeanGlycine maxe5
- Treatment
- exposure to high CO 2e1
- Outcome
- total leaf area, mean net assimilation ratee1
- Direction
- increasede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“At all NO − 3 levels except the lowest, exposure to high CO 2 resulted in increased total leaf area, mean net assimilation rate, NO − 3 uptake, and N utilization efficiency”
e5“The nonnodulating soybean plants were grown to maturity in controlled environment chambers”
Claim · model-written summary
High CO2 increased N utilization efficiency of soybean at all nitrate levels except the lowest.
- Taxon
- soybeanGlycine maxe5
- Treatment
- exposure to high CO 2e1
- Outcome
- N utilization efficiencye1
- Direction
- increasede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“At all NO − 3 levels except the lowest, exposure to high CO 2 resulted in increased total leaf area, mean net assimilation rate, NO − 3 uptake, and N utilization efficiency”
e5“The nonnodulating soybean plants were grown to maturity in controlled environment chambers”
Claim · model-written summary
High CO2 increased nitrate uptake of soybean at all nitrate levels except the lowest.
- Taxon
- soybeanGlycine maxe5
- Treatment
- exposure to high CO 2e1
- Outcome
- NO − 3 uptakee1
- Direction
- increasede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“At all NO − 3 levels except the lowest, exposure to high CO 2 resulted in increased total leaf area, mean net assimilation rate, NO − 3 uptake, and N utilization efficiency”
e5“The nonnodulating soybean plants were grown to maturity in controlled environment chambers”
Claim · model-written summary
Increased nitrate uptake was associated with larger root systems of soybean.
- Taxon
- soybeanGlycine maxe5
- Organ / stage
- root systemse2
- Outcome
- root systemse2
- Direction
- largere2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“Increased NO − 3 uptake was associated with larger root systems, as uptake per unit of root mass was lower than controls”
e5“The nonnodulating soybean plants were grown to maturity in controlled environment chambers”
Claim · model-written summary
Uptake per unit of root mass of soybean was lower than in controls.
- Taxon
- soybeanGlycine maxe5
- Outcome
- uptake per unit of root masse2
- Direction
- lowere2
- Comparator
- controlse2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“Increased NO − 3 uptake was associated with larger root systems, as uptake per unit of root mass was lower than controls”
e5“The nonnodulating soybean plants were grown to maturity in controlled environment chambers”
Claim · model-written summary
Carbon dioxide enrichment had no appreciable effect on dry matter partitioning or harvest index of soybean.
- Taxon
- soybeanGlycine maxe5
- Treatment
- Carbon dioxide enrichmente3
- Outcome
- dry matter partitioning among plant parts or harvest indexe3
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e3“Carbon dioxide enrichment had little effect on dry matter partitioning among plant parts or harvest index”
e5“The nonnodulating soybean plants were grown to maturity in controlled environment chambers”
Claim · model-written summary
Partitioning of soybean dry matter was related to nitrate supply.
- Taxon
- soybeanGlycine maxe5
- Treatment
- NO − 3 supplye4
- Outcome
- partitioninge4
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“Alterations in partitioning were related to differences in NO − 3 supply”
e5“The nonnodulating soybean plants were grown to maturity in controlled environment chambers”
The same questions in other papers
co2 · nutrient: efficiency · Glycine max (soybean)Positive and negative results
1 in the opposite direction
- no effect
co2 · nutrient: content · Glycine max (soybean)Positive and negative results
11 papers in the same direction as this paper · 14 in the opposite direction · 1 reporting no difference from an alternative
- no effect
- no effect
- positive
23 papers more in this group
See all 27 papers →co2 · yield · Glycine max (soybean)Positive and negative results
85 papers in the same direction as this paper · 10 in the opposite direction
- positive
- positive
- positive
92 papers more in this group
See all 96 papers →co2 · growth · Glycine max (soybean)Positive and negative results
82 papers in the same direction as this paper · 16 in the opposite direction · 2 reporting no difference from an alternative
- positive
- positive
- positive
97 papers more in this group
See all 101 papers →nitrogen · yield · Glycine max (soybean)Positive and negative results
317 papers in the same direction as this paper · 91 in the opposite direction · 7 reporting no difference from an alternative
- negative
- negative
- no effect
412 papers more in this group
See all 416 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.