Abstract
Abstract Previous work suggests that some sweet potato ( Ipomoea batatas , L.) cultivars can produce high storage root yields on soils without fertilizer N addition. This study was conducted to compare storage root yields, total biomass, N uptake and fibrous root weights of sweet potato cultivars grown on low N level soils with and without N addition. In 1987 and 1988, improved sweet potato cultivars developed at International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria were grown with and without 50 kg N ha −1 in Oxic Paleustalfs with low N and C concentrations. Yields of 21 to 38 Mg ha −1 were produced for four of the five improved cultivars grown in soil without N addition. Total biomass, foliage, fibrous root and storage root weights and N concentration in leaves were not influenced by fertilizer N addition. Up to 158 and 89 kg N ha −1 uptake in total biomass occurred with the +N and −N treatments, respectively. Indigenous soil N levels and fibrous root weights for − N vs. +N treatments could not account for the total N uptake and biomass produced on soils without N addition.
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Claims 6
Claim · model-written summary
Four of five improved sweet potato cultivars yielded 21 to 38 Mg ha −1 without nitrogen addition.
- Taxon
- Sweet Potato
_Flower.jpg?width=60)
Ipomoea batatast0 - Material
- improved cultivarse0
- Treatment
- without N additione0
- Outcome
- Yieldse0
- Value
- 21 to 38 Mg ha −1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_Flower.jpg?width=500)
Verbatim
e0“Yields of 21 to 38 Mg ha −1 were produced for four of the five improved cultivars grown in soil without N addition.”
t0“Sweet Potato”
Claim · model-written summary
Nitrogen addition did not influence total biomass, foliage, fibrous root or storage root weights.
- Taxon
- Sweet PotatoIpomoea batatast0
- Treatment
- fertilizer N additione0
- Outcome
- Total biomass, foliage, fibrous root and storage root weightse0
- Direction
- not influencede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Total biomass, foliage, fibrous root and storage root weights and N concentration in leaves were not influenced by fertilizer N addition.”
t0“Sweet Potato”
Claim · model-written summary
Nitrogen addition did not influence leaf nitrogen concentration.
- Taxon
- Sweet PotatoIpomoea batatast0
- Organ / stage
- leavese0
- Treatment
- fertilizer N additione0
- Outcome
- N concentration in leavese0
- Direction
- not influencede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Total biomass, foliage, fibrous root and storage root weights and N concentration in leaves were not influenced by fertilizer N addition.”
t0“Sweet Potato”
Claim · model-written summary
Total biomass nitrogen uptake reached 158 kg N ha −1 with nitrogen addition.
- Taxon
- Sweet PotatoIpomoea batatast0
- Treatment
- +Ne0
- Outcome
- N ha −1 uptake in total biomasse0
- Value
- 158e0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Up to 158 and 89 kg N ha −1 uptake in total biomass occurred with the +N and −N treatments, respectively.”
t0“Sweet Potato”
Claim · model-written summary
Total biomass nitrogen uptake reached 89 kg N ha −1 without nitrogen addition.
- Taxon
- Sweet PotatoIpomoea batatast0
- Treatment
- −Ne0
- Outcome
- N ha −1 uptake in total biomasse0
- Value
- 89 kg N ha −1e0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Up to 158 and 89 kg N ha −1 uptake in total biomass occurred with the +N and −N treatments, respectively.”
t0“Sweet Potato”
Claim · model-written summary
Indigenous soil nitrogen and fibrous root weights could not account for nitrogen uptake and biomass without nitrogen addition.
- Taxon
- Sweet PotatoIpomoea batatast0
- Organ / stage
- fibrous roote0
- Outcome
- total N uptake and biomass producede0
- Qualifier
- could not account fore0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Indigenous soil N levels and fibrous root weights for − N vs. +N treatments could not account for the total N uptake and biomass produced on soils without N addition.”
t0“Sweet Potato”
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