Abstract
Abstract The effect of soil water suction and root temperature on rates of nitrogen fixation, transpiration, and net photosynthesis of soybeans ( Glycine max (L.) Merr.) was studied in laboratory experiments. The range of root temperature and soil water suction considered was 15.6 to 37.8 C and 0.30 to 2.50 bars, respectively. With increasing root temperature rates of nitrogen fixation, transpiration and photosynthesis increased slowly at first and then rapidly until an optimum temperature was reached followed by a decrease at higher temperatures. Optimum temperatures were 27, 30, and 27 C for rates of nitrogen fixation, transpiration, and net photosynthesis, respectively. Rates of the three parameters decreased with increasing soil water suction. The amount of nitrogen fixed per unit of CO 2 absorbed was highest at a root temperature of 23.9 C and lowest at 37.8 C. This ratio decreased with increasing soil water suction at all temperatures considered. Changes in transpiration rate resulting from changes in soil temeprature were attributed to temperature effects on viscosity and metabolic activity. Effects of soil water suction and soil temperature on nitrogen fixation indicated in this study emphasize the complex symbiotic nature of the process. Mechanisms by which the two environmental parameters might affect the rate of fixation were indicated but not clearly elucidated by the results of the experiments.
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Claims 6
Claim · model-written summary
Nitrogen fixation increased with root temperature to an optimum of 27 C, then decreased.
- Taxon
- soybeans
Glycine maxe1 - Treatment
- increasing root temperaturee0
- Outcome
- nitrogen fixatione0
- Direction
- increasede0
- Value
- 27 Ce0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“With increasing root temperature rates of nitrogen fixation, transpiration and photosynthesis increased slowly at first and then rapidly until an optimum temperature was reached followed by a decrease at higher temperatures. Optimum temperatures were 27, 30, and 27 C for rates of nitrogen fixation, transpiration, and net photosynthesis, respectively.”
e1“The effect of soil water suction and root temperature on rates of nitrogen fixation, transpiration, and net photosynthesis of soybeans ( Glycine max (L.) Merr.) was studied in laboratory experiments.”
Claim · model-written summary
Transpiration increased with root temperature to an optimum of 30 C, then decreased.
- Taxon
- soybeansGlycine maxe1
- Treatment
- increasing root temperaturee0
- Outcome
- transpiratione0
- Direction
- increasede0
- Value
- 27, 30, and 27 Ce0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“With increasing root temperature rates of nitrogen fixation, transpiration and photosynthesis increased slowly at first and then rapidly until an optimum temperature was reached followed by a decrease at higher temperatures. Optimum temperatures were 27, 30, and 27 C for rates of nitrogen fixation, transpiration, and net photosynthesis, respectively.”
e1“The effect of soil water suction and root temperature on rates of nitrogen fixation, transpiration, and net photosynthesis of soybeans ( Glycine max (L.) Merr.) was studied in laboratory experiments.”
Claim · model-written summary
Net photosynthesis increased with root temperature to an optimum of 27 C, then decreased.
- Taxon
- soybeansGlycine maxe1
- Treatment
- increasing root temperaturee0
- Outcome
- net photosynthesise0
- Direction
- increasede0
- Value
- 27 Ce0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“With increasing root temperature rates of nitrogen fixation, transpiration and photosynthesis increased slowly at first and then rapidly until an optimum temperature was reached followed by a decrease at higher temperatures. Optimum temperatures were 27, 30, and 27 C for rates of nitrogen fixation, transpiration, and net photosynthesis, respectively.”
e1“The effect of soil water suction and root temperature on rates of nitrogen fixation, transpiration, and net photosynthesis of soybeans ( Glycine max (L.) Merr.) was studied in laboratory experiments.”
Claim · model-written summary
Increasing soil water suction decreased nitrogen fixation, transpiration and net photosynthesis.
- Taxon
- soybeansGlycine maxe1
- Treatment
- increasing soil water suctione0
- Outcome
- nitrogen fixation, transpiration, and net photosynthesise1
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Rates of the three parameters decreased with increasing soil water suction.”
e1“The effect of soil water suction and root temperature on rates of nitrogen fixation, transpiration, and net photosynthesis of soybeans ( Glycine max (L.) Merr.) was studied in laboratory experiments.”
Claim · model-written summary
Nitrogen fixed per unit of CO 2 absorbed was highest at 23.9 C and lowest at 37.8 C.
- Taxon
- soybeansGlycine maxe1
- Outcome
- nitrogen fixed per unit of CO 2 absorbede0
- Direction
- higheste0
- Value
- 23.9 Ce0
- Comparator
- 37.8 Ce0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The amount of nitrogen fixed per unit of CO 2 absorbed was highest at a root temperature of 23.9 C and lowest at 37.8 C.”
e1“The effect of soil water suction and root temperature on rates of nitrogen fixation, transpiration, and net photosynthesis of soybeans ( Glycine max (L.) Merr.) was studied in laboratory experiments.”
Claim · model-written summary
Nitrogen fixed per unit of CO 2 absorbed decreased with increasing soil water suction at all temperatures.
- Taxon
- soybeansGlycine maxe1
- Treatment
- increasing soil water suctione0
- Outcome
- nitrogen fixed per unit of CO 2 absorbede2
- Direction
- decreasede0
- Qualifier
- at all temperatures considerede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This ratio decreased with increasing soil water suction at all temperatures considered.”
e2“The amount of nitrogen fixed per unit of CO 2 absorbed was highest at a root temperature of 23.9 C and lowest at 37.8 C.”
e1“The effect of soil water suction and root temperature on rates of nitrogen fixation, transpiration, and net photosynthesis of soybeans ( Glycine max (L.) Merr.) was studied in laboratory experiments.”
The same questions in other papers
soil water · physiology: photosynthesis · Glycine max (soybean)Positive and negative results
3 papers in the same direction as this paper · 2 in the opposite direction
- positive
- positive
- negative
2 papers more in this group
See all 6 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.