Abstract
Abstract Splitting nitrogen (N) application is beneficial for enhancing sweetpotato growth and promoting optimum yields under reduced N rates; however, studies concerning how split N can affect sweetpotato N dynamics and utilization are limited. Field experiments were conducted from 2015 to 2016 to determine how split N application affects sweetpotato N uptake and N use efficiency (NUE) under a reduced N rate. Two cultivars (Xushu 22 and Shangshu 19) were planted under four N treatments, a conventional basal application of 100 kg N ha −1 (100:0), a basal application of 80 kg N ha −1 (80:0), two equal split applications of 80 kg N ha −1 (basal and 35 days after transplanting, 40:40) and a N omission treatment (N0). Data from two years revealed that sweetpotato yields decreased at a reduced 20% N rate with a basal application (80:0); however, the reduced 20% N rate with a split application (40:40) significantly increased the yield by 16.6–19.0%. Although the 80:0 treatment decreased sweetpotato N uptake, the 40:40 treatment increased the N uptake by increasing the N uptake rate and prolonging the duration of the fast N uptake phase. In comparison to the basal application, the split N application used N more efficiently, showing consistently higher levels of agronomic use efficiency, recovery efficiency, physiological efficiency and partial factor productivity. NUEs under split N improved due to increased N uptake during the middle and late growth stages and a higher N partition ratio to the storage root. The above results indicate that split N application provides better N for crop developmental stages and is recommended as an alternative approach to simultaneously increasing storage root yield and NUE under a reduced N rate in sweetpotato production in China.
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Claims 10
Claim · model-written summary
Basal 20% nitrogen reduction decreased yield.
- Taxon
- sweetpotato
_Flower.jpg?width=60)
Ipomoea batatase0 - Treatment
- a reduced 20% N rate with a basal application (80:0)e0
- Outcome
- sweetpotato yieldse0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_Flower.jpg?width=500)
Verbatim
e0“sweetpotato yields decreased at a reduced 20% N rate with a basal application (80:0)”
Claim · model-written summary
Split application at the reduced rate significantly raised yield by 16.6–19.0%.
- Taxon
- sweetpotatoIpomoea batatast0
- Treatment
- the reduced 20% N rate with a split application (40:40)e0
- Outcome
- yielde0
- Direction
- increasede0
- Value
- 16.6–19.0%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the reduced 20% N rate with a split application (40:40) significantly increased the yield by 16.6–19.0%”
t0“improves nitrogen uptake and use efficiency in sweetpotato”
Claim · model-written summary
Basal 80:0 application reduced nitrogen uptake.
- Taxon
- sweetpotatoIpomoea batatase0
- Treatment
- 80:0 treatmente0
- Outcome
- sweetpotato N uptakee0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the 80:0 treatment decreased sweetpotato N uptake”
Claim · model-written summary
Split 40:40 application increased nitrogen uptake.
- Taxon
- sweetpotatoIpomoea batatast0
- Treatment
- 40:40 treatmente0
- Outcome
- N uptakee0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the 40:40 treatment increased the N uptake by increasing the N uptake rate and prolonging the duration of the fast N uptake phase”
t0“improves nitrogen uptake and use efficiency in sweetpotato”
Claim · model-written summary
Split application increased nitrogen uptake rate.
- Taxon
- sweetpotatoIpomoea batatast0
- Treatment
- 40:40 treatmente0
- Outcome
- N uptake ratee0
- Direction
- increasinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the 40:40 treatment increased the N uptake by increasing the N uptake rate and prolonging the duration of the fast N uptake phase”
t0“improves nitrogen uptake and use efficiency in sweetpotato”
Claim · model-written summary
Split application prolonged the fast nitrogen uptake phase.
- Taxon
- sweetpotatoIpomoea batatast0
- Treatment
- 40:40 treatmente0
- Outcome
- duration of the fast N uptake phasee0
- Direction
- prolonginge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the 40:40 treatment increased the N uptake by increasing the N uptake rate and prolonging the duration of the fast N uptake phase”
t0“improves nitrogen uptake and use efficiency in sweetpotato”
Claim · model-written summary
Split nitrogen application improved four nitrogen use efficiency measures.
- Taxon
- sweetpotatoIpomoea batatast0
- Treatment
- split N applicatione0
- Outcome
- agronomic use efficiency, recovery efficiency, physiological efficiency and partial factor productivitye0
- Direction
- highere0
- Comparator
- basal applicatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In comparison to the basal application, the split N application used N more efficiently, showing consistently higher levels of agronomic use efficiency, recovery efficiency, physiological efficiency and partial factor productivity”
t0“improves nitrogen uptake and use efficiency in sweetpotato”
Claim · model-written summary
Split application increased middle and late stage uptake.
- Taxon
- sweetpotatoIpomoea batatast0
- Treatment
- split Ne0
- Outcome
- N uptake during the middle and late growth stagese0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“NUEs under split N improved due to increased N uptake during the middle and late growth stages”
t0“improves nitrogen uptake and use efficiency in sweetpotato”
Claim · model-written summary
Split application raised the nitrogen partition ratio to storage roots.
- Taxon
- sweetpotatoIpomoea batatast0
- Treatment
- split Ne0
- Outcome
- N partition ratio to the storage roote0
- Direction
- highere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“NUEs under split N improved due to increased N uptake during the middle and late growth stages and a higher N partition ratio to the storage root”
t0“improves nitrogen uptake and use efficiency in sweetpotato”
Claim · model-written summary
The authors recommend split nitrogen application at reduced rate.
- Taxon
- sweetpotatoIpomoea batatase0
- Outcome
- split N applicatione0
- Qualifier
- under a reduced N ratee0
- Setting
- Chinae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“split N application provides better N for crop developmental stages and is recommended as an alternative approach to simultaneously increasing storage root yield and NUE under a reduced N rate in sweetpotato production in China”
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
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