Abstract
Abstract A 2‐year field study was conducted to determine the possibility of supplementing soil and symbiotically‐fixed nitrogen of soybeans with nitrogen fertilizer. In 1947, during a hot dry growing season marked responses were obtained from added nitrogen. The number of nodules per plant decreased 80 to 90%, there were appreciable increases in seed yields, nitrogen content of the seed increased, and oil content decreased. In 1949, with adequate rainfall, moderate temperatures, and 30 to 40 days additional growing season there was little to no response to added nitrogen. The number of nodules per plant on the untreated plots was larger than in 1947, and the largest application of ammonium nitrate resulted in only a 35% decrease in number of nodules. The yield of seed increased very little, and no change occurred in the nitrogen and oil contents of the seed. A comparison of three dates of side‐dressing with plow‐down treatments indicated that the most effective utilization occurred with plow‐down applications. This experiment helps explain some of the variation in response of soybeans to nitrogen fertilizers. Rainfall and temperature conditions during the growing season apparently have a direct influence on the sufficiency of symbiotically‐fixed nitrogen for maximum yields, thus indirectly influencing the response to added nitrogen.
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Claims 11
Claim · model-written summary
Added nitrogen decreased the number of nodules per plant by 80 to 90% in the hot dry 1947 season.
- Taxon
- Soybeans
Glycine maxt0 - Treatment
- added nitrogene1
- Outcome
- number of nodules per plante2
- Direction
- decreasede2
- Value
- 80 to 90%e2
- Setting
- hot dry growing seasone1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“of Soybeans”
e1“In 1947, during a hot dry growing season marked responses were obtained from added nitrogen”
e2“The number of nodules per plant decreased 80 to 90%, there were appreciable increases in seed yields, nitrogen content of the seed increased, and oil content decreased”
Claim · model-written summary
Added nitrogen increased seed yield in the hot dry 1947 season.
- Taxon
- SoybeansGlycine maxt0
- Treatment
- added nitrogene1
- Outcome
- seed yieldse2
- Direction
- increasese2
- Setting
- hot dry growing seasone1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“of Soybeans”
e1“In 1947, during a hot dry growing season marked responses were obtained from added nitrogen”
e2“The number of nodules per plant decreased 80 to 90%, there were appreciable increases in seed yields, nitrogen content of the seed increased, and oil content decreased”
Claim · model-written summary
Added nitrogen increased seed nitrogen content in the hot dry 1947 season.
- Taxon
- SoybeansGlycine maxt0
- Treatment
- added nitrogene1
- Outcome
- nitrogen content of the seede2
- Direction
- increasede2
- Setting
- hot dry growing seasone1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“of Soybeans”
e1“In 1947, during a hot dry growing season marked responses were obtained from added nitrogen”
e2“The number of nodules per plant decreased 80 to 90%, there were appreciable increases in seed yields, nitrogen content of the seed increased, and oil content decreased”
Claim · model-written summary
Added nitrogen decreased seed oil content in the hot dry 1947 season.
- Taxon
- SoybeansGlycine maxt0
- Treatment
- added nitrogene1
- Outcome
- oil contente2
- Direction
- decreasede2
- Setting
- hot dry growing seasone1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“of Soybeans”
e1“In 1947, during a hot dry growing season marked responses were obtained from added nitrogen”
e2“The number of nodules per plant decreased 80 to 90%, there were appreciable increases in seed yields, nitrogen content of the seed increased, and oil content decreased”
Claim · model-written summary
In 1949, with adequate rainfall and moderate temperatures, soybeans showed little to no response to added nitrogen.
- Taxon
- SoybeansGlycine maxt0
- Outcome
- response to added nitrogene3
- Qualifier
- little to noe3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“of Soybeans”
e3“In 1949, with adequate rainfall, moderate temperatures, and 30 to 40 days additional growing season there was little to no response to added nitrogen”
Claim · model-written summary
Nodule number per plant on untreated plots was larger in 1949 than in 1947.
- Taxon
- SoybeansGlycine maxt0
- Outcome
- number of nodules per plante4
- Qualifier
- larger than in 1947e4
- Comparator
- untreated plotse4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“of Soybeans”
e4“The number of nodules per plant on the untreated plots was larger than in 1947”
Claim · model-written summary
The largest ammonium nitrate application decreased nodule number by only 35%.
- Taxon
- SoybeansGlycine maxt0
- Treatment
- largest application of ammonium nitratee5
- Outcome
- number of nodulese5
- Direction
- decreasee5
- Value
- 35%e5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“of Soybeans”
e5“the largest application of ammonium nitrate resulted in only a 35% decrease in number of nodules”
Claim · model-written summary
Added nitrogen increased seed yield very little in the 1949 trial.
- Taxon
- SoybeansGlycine maxt0
- Treatment
- added nitrogene3
- Outcome
- yield of seede6
- Direction
- increasede6
- Qualifier
- very littlee6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“of Soybeans”
e3“In 1949, with adequate rainfall, moderate temperatures, and 30 to 40 days additional growing season there was little to no response to added nitrogen”
e6“The yield of seed increased very little, and no change occurred in the nitrogen and oil contents of the seed”
Claim · model-written summary
Added nitrogen caused no change in seed nitrogen and oil contents in 1949.
- Taxon
- SoybeansGlycine maxt0
- Treatment
- added nitrogene3
- Outcome
- nitrogen and oil contentse6
- Direction
- no changee6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“of Soybeans”
e3“In 1949, with adequate rainfall, moderate temperatures, and 30 to 40 days additional growing season there was little to no response to added nitrogen”
e6“The yield of seed increased very little, and no change occurred in the nitrogen and oil contents of the seed”
Claim · model-written summary
Plow-down applications were the most effective utilization of applied nitrogen compared with side-dressing.
- Taxon
- SoybeansGlycine maxt0
- Treatment
- plow‐down applicationse7
- Outcome
- utilizatione7
- Direction
- most effectivee7
- Comparator
- side‐dressinge7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“of Soybeans”
e7“A comparison of three dates of side‐dressing with plow‐down treatments indicated that the most effective utilization occurred with plow‐down applications”
Claim · model-written summary
Rainfall and temperature during the growing season are apparently a direct influence on the sufficiency of symbiotically fixed nitrogen for maximum soybean yields.
- Taxon
- SoybeansGlycine maxt0
- Outcome
- sufficiency of symbiotically‐fixed nitrogen for maximum yieldse6
- Qualifier
- Rainfall and temperature conditions during the growing seasone6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“of Soybeans”
e6“Rainfall and temperature conditions during the growing season apparently have a direct influence on the sufficiency of symbiotically‐fixed nitrogen for maximum yields”
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