Abstract
Nitrogen application during soybean [ Glycine max (L.) Merrill] reproductive stages has the potential to increase soybean productivity. The objective of this study was to determine the impact of N fertilizer applied to the soil at the beginning pod growth stage on soybean yield and grain quality. Additional objectives were to study alternative N fertilizer and application practices that might enhance soybean use of applied N. A field study was conducted at five locations in Iowa during 1999 and 2000. Nitrogen treatments were urea and polymer‐coated urea broadcast and subsurface band placed between the rows at 45 and 90 kg N ha −1 and a no‐N control. The study showed few, small, and inconsistent effects of N material, placement, and rate on grain yield and quality components at individual sites or when combined across individual sites. There were no significant effects on grain yield, with only a 39 kg ha −1 increase from applied N. Grain protein, oil, and fiber concentrations were the same with or without N application. Aboveground plant dry matter (DM) at the R6 growth stage was greater with the higher N rate, but plant DM with N application was lower than the no‐N control. Nitrogen concentration in plant DM was significantly increased with applied N. In conclusion, N application increased N concentration in R6 soybean plants, but N rate and alternative application practices had no positive effect on plant DM, grain N concentration and removal, grain yield, or grain quality components. It was concluded that growers should not consider fertilizer N applied to soil during early reproductive stages as a method to increase soybean yield or grain quality.
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Claims 8
Claim · model-written summary
Nitrogen material, placement and rate had few, small and inconsistent effects on yield and quality.
- Taxon
- soybean
Glycine maxt0 - Treatment
- N material, placement, and ratee0
- Outcome
- grain yield and quality componentse0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“few, small, and inconsistent effects of N material, placement, and rate on grain yield and quality components”
t0“Soybean”
Claim · model-written summary
Applied nitrogen did not significantly affect grain yield; the observed increase was 39 kg ha−1.
- Taxon
- soybeanGlycine maxt0
- Treatment
- applied Ne0
- Outcome
- grain yielde0
- Direction
- increaseinferrede0
- Value
- 39 kg ha −1e0
- Comparator
- no‐N controle1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“There were no significant effects on grain yield, with only a 39 kg ha −1 increase from applied N.”
t0“Soybean”
e1“the no‐N control”
Claim · model-written summary
Grain protein, oil and fiber concentrations were unchanged with nitrogen application.
- Taxon
- soybeanGlycine maxt0
- Treatment
- N applicatione0
- Outcome
- Grain protein, oil, and fiber concentrationse0
- Direction
- the samee0
- Comparator
- without N applicatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grain protein, oil, and fiber concentrations were the same with or without N application.”
t0“Soybean”
Claim · model-written summary
Aboveground dry matter at R6 was greater at the higher nitrogen rate.
- Taxon
- soybeanGlycine maxt0
- Organ / stage
- R6 growth stagee0
- Treatment
- higher N ratee0
- Outcome
- Aboveground plant dry matter (DM)e0
- Direction
- greatere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Aboveground plant dry matter (DM) at the R6 growth stage was greater with the higher N rate”
t0“Soybean”
Claim · model-written summary
Plant dry matter with nitrogen was lower than the no-N control.
- Taxon
- soybeanGlycine maxt0
- Treatment
- N applicatione0
- Outcome
- plant DMe0
- Direction
- lowere0
- Comparator
- no‐N controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“plant DM with N application was lower than the no‐N control.”
t0“Soybean”
Claim · model-written summary
Applied nitrogen significantly increased nitrogen concentration in plant dry matter.
- Taxon
- soybeanGlycine maxt0
- Treatment
- applied Ne0
- Outcome
- Nitrogen concentration in plant DMe0
- Direction
- significantly increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nitrogen concentration in plant DM was significantly increased with applied N.”
t0“Soybean”
Claim · model-written summary
Nitrogen rate and alternative practices had no positive effect on grain nitrogen concentration and removal.
- Taxon
- soybeanGlycine maxt0
- Treatment
- N rate and alternative application practicese0
- Outcome
- grain N concentration and removale0
- Direction
- no positive effecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“N rate and alternative application practices had no positive effect on plant DM, grain N concentration and removal, grain yield, or grain quality components.”
t0“Soybean”
Claim · model-written summary
Growers should not use early reproductive soil nitrogen to increase yield or grain quality.
- Taxon
- soybeanGlycine maxt0
- Outcome
- fertilizer N applied to soil during early reproductive stagese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“growers should not consider fertilizer N applied to soil during early reproductive stages as a method to increase soybean yield or grain quality.”
t0“Soybean”
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