Abstract
The optimum rate of nitrogen application for quality and maximum herbage production was determined. Sweet potato crops applied with various rates of nitrogen (N) significantly produced higher yields than the control. The herbage yield increased as the N rates were increased but the ROI [return on investment] started to decline at 120- and 150 kg N/ha per application with only 26 and 8%, respectively. The optimum rate of N application after every herbage harvest was at 30 kg/ha. This rate gave 34% greater herbage yield and 14% more on ROI than the control. Other on-farm trials should be conducted in 2 or more sites during the wet and dry seasons. The N rates and the frequency of N application may be reduced since its effect on herbage yield was not significant.
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Claims 9
Claim · model-written summary
Nitrogen application increased sweet potato herbage yield relative to control.
- Taxon
- Sweet potato
_Flower.jpg?width=60)
Ipomoea batatase0 - Treatment
- various rates of nitrogen (N)e0
- Outcome
- yieldse0
- Direction
- highere0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_Flower.jpg?width=500)
Verbatim
e0“Sweet potato crops applied with various rates of nitrogen (N) significantly produced higher yields than the control”
Claim · model-written summary
Herbage yield rose as nitrogen rates increased.
- Taxon
- sweet potatoIpomoea batatast0
- Treatment
- N ratese0
- Outcome
- herbage yielde0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The herbage yield increased as the N rates were increased”
t0“sweet potato”
Claim · model-written summary
Return on investment declined at 120 kg N/ha per application to 26%.
- Taxon
- sweet potatoIpomoea batatast0
- Treatment
- 120- and 150 kg N/ha per applicatione0
- Outcome
- ROI [return on investment]e0
- Direction
- declinee0
- Value
- 26e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the ROI [return on investment] started to decline at 120- and 150 kg N/ha per application with only 26 and 8%, respectively”
t0“sweet potato”
Claim · model-written summary
Return on investment declined at 150 kg N/ha per application to 8%.
- Taxon
- sweet potatoIpomoea batatast0
- Treatment
- 150 kg N/ha per applicatione0
- Outcome
- ROI [return on investment]e0
- Direction
- declinee0
- Value
- 8%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the ROI [return on investment] started to decline at 120- and 150 kg N/ha per application with only 26 and 8%, respectively”
t0“sweet potato”
Claim · model-written summary
The recommended nitrogen rate after each herbage harvest was 30 kg/ha.
- Taxon
- sweet potatoIpomoea batatast0
- Outcome
- optimum rate of N application after every herbage harveste0
- Value
- 30 kg/hae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The optimum rate of N application after every herbage harvest was at 30 kg/ha”
t0“sweet potato”
Claim · model-written summary
At 30 kg/ha nitrogen, herbage yield was 34% greater than control.
- Taxon
- sweet potatoIpomoea batatast0
- Treatment
- 30 kg/hae1
- Outcome
- herbage yielde0
- Direction
- greatere0
- Value
- 34%e0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This rate gave 34% greater herbage yield and 14% more on ROI than the control”
t0“sweet potato”
e1“The optimum rate of N application after every herbage harvest was at 30 kg/ha”
Claim · model-written summary
At 30 kg/ha nitrogen, return on investment was 14% more than control.
- Taxon
- sweet potatoIpomoea batatast0
- Treatment
- 30 kg/hae1
- Outcome
- ROIe0
- Direction
- moree0
- Value
- 14%e0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This rate gave 34% greater herbage yield and 14% more on ROI than the control”
t0“sweet potato”
e1“The optimum rate of N application after every herbage harvest was at 30 kg/ha”
Claim · model-written summary
The authors recommended trials at two or more sites in wet and dry seasons.
- Taxon
- sweet potatoIpomoea batatast0
- Outcome
- on-farm trials should be conducted in 2 or more sites during the wet and dry seasonse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Other on-farm trials should be conducted in 2 or more sites during the wet and dry seasons”
t0“sweet potato”
Claim · model-written summary
The authors suggested reducing nitrogen rates and application frequency because herbage yield effects were not significant.
- Taxon
- sweet potatoIpomoea batatast0
- Outcome
- N rates and the frequency of N application may be reducede0
- Qualifier
- effect on herbage yield was not significante0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The N rates and the frequency of N application may be reduced since its effect on herbage yield was not significant”
t0“sweet potato”
The same questions in other papers
nitrogen · yield · Ipomoea batatas (sweet potato)Results differ
30 papers in the same direction as this paper · 4 in the opposite direction
- negative
- no effect
- no effect
31 papers more in this group
See all 35 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.